m8ta
You are not authenticated, login.
text: sort by
tags: modified
type: chronology
{231} is owned by tlh24.
[0] Suner S, Fellows MR, Vargas-Irwin C, Nakata GK, Donoghue JP, Reliability of signals from a chronically implanted, silicon-based electrode array in non-human primate primary motor cortex.IEEE Trans Neural Syst Rehabil Eng 13:4, 524-41 (2005 Dec)

[0] Isoda M, Hikosaka O, Role for subthalamic nucleus neurons in switching from automatic to controlled eye movement.J Neurosci 28:28, 7209-18 (2008 Jul 9)

[0] Sodagar AM, Wise KD, Najafi K, A fully integrated mixed-signal neural processor for implantable multichannel cortical recording.IEEE Trans Biomed Eng 54:6 Pt 1, 1075-88 (2007 Jun)

[0] Aflalo TN, Graziano MS, Relationship between unconstrained arm movements and single-neuron firing in the macaque motor cortex.J Neurosci 27:11, 2760-80 (2007 Mar 14)

[0] Moran DW, Schwartz AB, Motor cortical representation of speed and direction during reaching.J Neurophysiol 82:5, 2676-92 (1999 Nov)

[0] Kennedy PR, Mirra SS, Bakay RA, The cone electrode: ultrastructural studies following long-term recording in rat and monkey cortex.Neurosci Lett 142:1, 89-94 (1992 Aug 3)

[0] Boline J, Ashe J, On the relations between single cell activity in the motor cortex and the direction and magnitude of three-dimensional dynamic isometric force.Exp Brain Res 167:2, 148-59 (2005 Nov)

[0] Ashe J, Georgopoulos AP, Movement parameters and neural activity in motor cortex and area 5.Cereb Cortex 4:6, 590-600 (1994 Nov-Dec)

[0] Hepp-Reymond M, Kirkpatrick-Tanner M, Gabernet L, Qi HX, Weber B, Context-dependent force coding in motor and premotor cortical areas.Exp Brain Res 128:1-2, 123-33 (1999 Sep)

[0] Maier MA, Bennett KM, Hepp-Reymond MC, Lemon RN, Contribution of the monkey corticomotoneuronal system to the control of force in precision grip.J Neurophysiol 69:3, 772-85 (1993 Mar)[1] Smith AM, Hepp-Reymond MC, Wyss UR, Relation of activity in precentral cortical neurons to force and rate of force change during isometric contractions of finger muscles.Exp Brain Res 23:3, 315-32 (1975 Sep 29)

[0] Amirikian B, Georgopoulos AP, Directional tuning profiles of motor cortical cells.Neurosci Res 36:1, 73-9 (2000 Jan)

[0] Teich MC, Heneghan C, Lowen SB, Ozaki T, Kaplan E, Fractal character of the neural spike train in the visual system of the cat.J Opt Soc Am A Opt Image Sci Vis 14:3, 529-46 (1997 Mar)

[0] Afanas'ev SV, Tolkunov BF, Rogatskaya NB, Orlov AA, Filatova EV, Sequential rearrangements of the ensemble activity of putamen neurons in the monkey brain as a correlate of continuous behavior.Neurosci Behav Physiol 34:3, 251-8 (2004 Mar)

{927}
hide / / print
ref: Bartels-2008.09 tags: neurotrophic kennedy speech FM transmitter wireless Georga recording electrophysiology electrode date: 01-19-2017 02:18 gmt revision:6 [5] [4] [3] [2] [1] [0] [head]

PMID-18672003[0] Neurotrophic electrode: method of assembly and implantation into human motor speech cortex.

  • Glass electrode with 3-4 2mil Teflon insulated Au wires within it to record spiking.
  • Induce neurites (e.g. dendrites, axons, blood vessels, oligodendrocytes) to grow up into it using autologous sciatic nerve, and stay for the lifetime of the patient (Kennedy 1989) [1].
    • Histology has revealed axons, but not neurons, within the tissue inside the tip. (Kennedy 1989, 1992a.)
    • No glia in rat and monkey tests; PMID-1421115
    • Inserted 5-6mm into the cortex at an angle of 45 deg. far!?
  • Bipolar amplification on pairs of the Au wires.
  • patients damaged their electrodes due to spasms; same for monkeys, presumably. Seems the electronice and gold wires are also highly fragile. I'm quite familiar with this.
  • Includes a sine wave source for calibration. good idea!
  • Inductively powered @ 1Mhz.
  • FM modulation at 39.2Mz and 43.9Mhz. COTS?
    • The implantable electronics are bulky as can be seen in Figs. 14 and ​and 19. (what a mess?!)
  • 3 patients, 4 years in 2 patients that dies from unrelated causes, over 3 years in a third.
  • describe construction of electrode -- not complicated.

____References____

[0] Bartels J, Andreasen D, Ehirim P, Mao H, Seibert S, Wright EJ, Kennedy P, Neurotrophic electrode: method of assembly and implantation into human motor speech cortex.J Neurosci Methods 174:2, 168-76 (2008 Sep 30)
[1] Kennedy PR, The cone electrode: a long-term electrode that records from neurites grown onto its recording surface.J Neurosci Methods 29:3, 181-93 (1989 Sep)

{597}
hide / / print
ref: Suner-2005.12 tags: Suner Utah probe electrophysiology reliability chronic electrode recording longevity histology MEA date: 01-31-2013 22:27 gmt revision:7 [6] [5] [4] [3] [2] [1] [head]

PMID-16425835Reliability of signals from a chronically implanted, silicon-based electrode array in non-human primate primary motor cortex

  • claim that they have done a logitudinal development series that included 39 array implants in 18 monkeys.
  • can get reliable recordings out to 3 months (only? probably the array was forced out of the brain?)
    • however, it seems that their recording quality did not decrease dramatically over those 3 months.
  • excellent methods section.
  • also {1027}

____References____

{823}
hide / / print
ref: Kruger-2010.05 tags: microelectrode array nichrome 7 years rhesus electrophysiology MEA Kruger oblique inverted date: 01-29-2013 07:54 gmt revision:7 [6] [5] [4] [3] [2] [1] [head]

PMID-20577628[0] Seven years of recording from monkey cortex with a chronically implanted multiple electrode.

  • Seven years!! good recordings the whole time, too. As they say, this is a clinically realistic time period. Have they solved the problem?
  • Used 12.5um Ni-Cr-Al wire insulated with 3um of polymide.
    • Wires were then glued to an 8x8 connector block using conductive epoxy.
    • Glued the bundle together with a solution of plexiglas in dichloroethane.
    • Then introduced the 0.3mm bundle into a j-shaped cannula. This allowed them to approach the gray matter inverted, from below (the white matter).
    • implanted 64 ch array into ventral premotor cortex (arm representation?).
  • No apparent degradation of recording quality over that time.
  • Had some serious problems with the quality of their connector.
    • They recommend: "Rather, the contacts on the head should be made from noble metals and be flat or shallowly hollow, so that they can be easily cleaned, and no male contacts can break."
    • Really need to amplify and multiplex prior connector (imho).
  • Claim that them managed to record from two neurons on one channel for nearly 7 years (ch 54).
  • They cite us, but only to indicate that we recommend slow penetration of the brain. They agree with our results that lowering of individual electrodes is better than all at once.

____References____

[0] Kruger J, Caruana F, Volta RD, Rizzolatti G, Seven years of recording from monkey cortex with a chronically implanted multiple microelectrode.Front Neuroengineering 3 Issue 6 (2010 May 28)

{158}
hide / / print
ref: Hashimoto-2003.03 tags: DBS STN subthalamic nucleus globus pallidus electrophysiology date: 03-07-2012 21:57 gmt revision:3 [2] [1] [0] [head]

PMID-12629196[0] Stimulation of the Subthalamic Nucleus Changes the Firing Pattern of Pallidal Neurons

  • why does STN stim work? investigated the effects of STN HFS on neuronal activity of GPi and GPe.
  • monkeys were treated with MPTP
  • used a scaled-down version of human DBS stimulator (cool!)
  • high frequency stimulation resulted in stimulus-synchronized regular firing pattern, plus an overall increase in pallidal firing rate.
    • they think that this synchrony may underlie the beneficial effect of HFS in the STN
  • only behavior was, apparently, what amplitude and frequency were required to alleviate parkinsonian symptoms.
  • if i do DBS in normal monkeys, is there anything to say that the effect will be similar or comparable to treatment stimulation?
  • they remind us that HFS = lesion in terms of alleviating symptoms of parkinsons.

____References____

[0] Hashimoto T, Elder CM, Okun MS, Patrick SK, Vitek JL, Stimulation of the subthalamic nucleus changes the firing pattern of pallidal neurons.J Neurosci 23:5, 1916-23 (2003 Mar 1)

{116}
hide / / print
ref: Iansek-1980.04 tags: globus pallidus GPe GPi electrophysiology 1980 date: 02-29-2012 18:17 gmt revision:2 [1] [0] [head]

PMID-7411442 The monkey globus pallidus: neuronal discharge properties in relation to movement.

  • motor units are generally inactive during inactivity. the relationship to movement of the discharges of such neurons was found to be very specific
    • This is in comparison to other results, which report a sustained firing, esp in GPi.
  • the discharges (as analyzed through histograms) of many neurones were related to only a particular direction of movement about one joint in the right limb.
  • some discharges were related to multijoint movements -> probably due to control of contraction of particular muscles.
    • nonetheless, this relationship was a loose one; there is not a tight coupling between pallidal activity and muscle contraction.
  • some responded to ipsilateral as well as contralateral movements.
    • PMID-7925805 Unilateral leasions in the GP results in bilateral increase in reaction time. hence, GP is involved in initiation. RT speed eventually recovered.
  • only the posterior globus pallidus - well posterior to the maximum expansion - contained movement related cells.
    • the a-p stereotaxic coordinates were less useful than the location of the maximum mediolateral width of the structure.
    • cells occurred in clusters, separated by regoins of non-movement related.
  • cells in the internal segment had no such organization.
  • many of the non-movement related neurons were tonically active.
  • this was before there was A/D recording, apparently!

{164}
hide / / print
ref: DeLong-1985.02 tags: globus pallidus subthalamic STN electrophysiology Georgopoulos DeLong DBS date: 02-24-2012 21:50 gmt revision:5 [4] [3] [2] [1] [0] [head]

PMID-3981228[0] Primate globus pallidus and subthalamic nucleus: functional organization

  • cells respond to arm, leg, and orofacial movements (mostly in the arm tho)
  • ~25% of these responded to passive joint movement - the latency is in accord with proprioceptive driving.
  • arm-related neurons were found throughout the rostrocaudal extent of both globus pallidus segments
  • look @ the articles that cite this!

____References____

[0] DeLong MR, Crutcher MD, Georgopoulos AP, Primate globus pallidus and subthalamic nucleus: functional organization.J Neurophysiol 53:2, 530-43 (1985 Feb)

{161}
hide / / print
ref: Bergman-1998.01 tags: basal ganglia globus pallidus electrophysiology parkinsons 2001 DBS date: 02-22-2012 18:52 gmt revision:5 [4] [3] [2] [1] [0] [head]

PMID-9464684[0] Physiological aspects of information processing in the basal ganglia of normal and parkinsonian primates.

  • The firing of neurons in the globus pallidus of normal monkeys is almost always uncorrelated.
  • after MPTP treatment, the firing patterns of GP became correlated and oscillatory (see the figures!!)
  • dopamine must support normal segregation of the informational channels in the basal ganglia, and breakdown of this causes the pathology of PD.
  • has a decent diagram of the basal ganglia-thalamo-cortical circuits.
  • two different hypotheses of BG function: segregated and convergent. data support the former.

____References____

[0] Bergman H, Feingold A, Nini A, Raz A, Slovin H, Abeles M, Vaadia E, Physiological aspects of information processing in the basal ganglia of normal and parkinsonian primates.Trends Neurosci 21:1, 32-8 (1998 Jan)

{654}
hide / / print
ref: Isoda-2008.07 tags: STN switching motor control scaccades monkeys electrophysiology DBS date: 02-22-2012 15:02 gmt revision:5 [4] [3] [2] [1] [0] [head]

PMID-18614691[0] Role for subthalamic nucleus neurons in switching from automatic to controlled eye movement.

  • we found neurons that showed a phasic change in activity specifically before volitionally controlled saccades which were switched from automatic saccades
  • A majority of switch-related neurons were considered to inhibit no-longer-valid automatic processes, and the inhibition started early enough to enable the animal to switch.
  • We suggest that the STN mediates the control signal originated from the medial frontal cortex and implements the behavioral switching function using its connections with other basal ganglia nuclei and the superior colliculus.
  • neurons have a really high rate of spiking - what we observe in DBS surgeries.
  • nice. There may be alternate explanations, but this one is plausible.

____References____

{1122}
hide / / print
ref: Gale-2009.03 tags: STN DBS monkey comparison electrophysiology date: 02-21-2012 16:34 gmt revision:2 [1] [0] [head]

PMID-19167367[0] Subthalamic nucleus discharge patterns during movement in the normal monkey and Parkinsonian patient.

  • Compared STN activity in normal monkeys and parkinsonian humans performing the same joystick target acquisition task.
  • PD neurons were much burstier, and had lower variance in responses.
  • Simultaneously recorded neurons in the human demonstrated consistent oscillatory synchronization at restricted frequency bands, whereas synchronized oscillatory neurons in the monkey were not restricted to distinct frequencies (this is possibly not meaningful).
  • the net effect of PD may be a reduction in the physiological degrees of freedom of BG neurons with diminished information carrying capacity.
  • PETHs look bad compared to our results.

____References____

[0] Gale JT, Shields DC, Jain FA, Amirnovin R, Eskandar EN, Subthalamic nucleus discharge patterns during movement in the normal monkey and Parkinsonian patient.Brain Res 1260no Issue 15-23 (2009 Mar 13)

{120}
hide / / print
ref: Bergman-1994.08 tags: subthalamic nucleus STN basal ganglia globus pallidus electrophysiology 1994 MPTP DBS date: 01-26-2012 17:19 gmt revision:3 [2] [1] [0] [head]

PMID-7983515[0] The primate subthalamic nucleus. II. Neuronal activity in the MPTP model of parkinsonism

  • idea: record from STN and GPi before and after MPTP treatment in green monkeys.
  • recorded 4-8hz periodic activity (via autocorrelograms) in significantly more neurons from the MPTP treated animals in both the STN and GPi.
  • mean firing rate was increased in STN,
  • tremor-correlated cells found in both.
  • burst activity higher in both, too.
  • modulations in firing rate due to the application of flexion and extension torque pulses were higher in MPTP animals (duration and amplitude), in both areas.
  • spikes were longer in MPTP
  • no tyrosene hydroxylase activity in the PD mks.
  • PD tremor only frequently occurs in green mks following MPTP

____References____

[0] Bergman H, Wichmann T, Karmon B, DeLong MR, The primate subthalamic nucleus. II. Neuronal activity in the MPTP model of parkinsonism.J Neurophysiol 72:2, 507-20 (1994 Aug)

{214}
hide / / print
ref: Harrison-2003.06 tags: CMOS amplifier headstage electrophysiology neural_recording low_power chopper Reid Harrison date: 01-16-2012 04:43 gmt revision:12 [11] [10] [9] [8] [7] [6] [head]

IEEE-1201998 (pdf) A low-power low-noise CMOS amplifier for neural recording applications

  • detail novel MOS-bipolar pseudoresistor element to permit amplification of low-frequency signals down to milihertz range.
  • 80 microwatt spike amplifier in 0.16mm^2 silicon with 1.5 um CMOS, 1 microwatt EEG amplifier
  • input-referred noise of 2.2uV RMS.
  • has a nice graph comparing the power vs. noise for a number of other published designs
  • i doubt the low-frequency amplification really matters for neural recording, though certainly it matters for EEG.
    • they give an equation for the noise efficiency factor (NEF), as well as much detailed background.
    • NEF better than any prev. reported. Theoretical limit is 2.9 for this topology; they measure 4.8
  • does not compare well to Medtronic amp: http://www.eetimes.com/news/design/showArticle.jhtml?articleID=197005915
    • 2 microwatt! @ 1.8V
    • chopper-stabilized
    • not sure what they are going to use it for - the battery will be killed it it has to telemeter anything!
    • need to find the report for this.
  • tutorial on chopper-stabilized amplifiers -- they have nearly constant noise v.s. frequency, and very low input/output offset.
  • References: {1056} Single unit recording capabilities of a 100 microelectrode array. Nordhausen CT, Maynard EM, Normann RA.
  • [5] see {1041}
  • [9] {1042}
  • [12] {1043}
____References____

Harrison, R.R. and Charles, C. A low-power low-noise CMOS amplifier for neural recording applications Solid-State Circuits, IEEE Journal of 38 6 958 - 965 (2003)

{966}
hide / / print
ref: Olds-1967.01 tags: Olds 1967 limbic system operant conditioning recording rats electrophysiology BMI date: 01-06-2012 03:59 gmt revision:2 [1] [0] [head]

PMID-6077726[0] The limbic system and behavioral reinforcement

  • Can't seem to find Olds 1965, as was a conference proceeding .. this will have to do, despite the lack of figures. images/966_1.pdf
  • First reference I can find of chronic (several weeks) (4-9 microelectrodes, single) recording from the rat.
  • Basically modern methods: commutator + solid state preamplifiers mounted to a counterbalanced slack-relieving arm.
    • If unit responses were observed in recordings from a given probe a week after surgery they were usually recordable indefinitely. 44 years later ...
  • Used a primitive but effective analog spike discriminator based on:
    • minimum amplitude
    • maximum amplitude
    • minimum fall time
    • maximum fall time.
  • Also had a head movement artifact detector, which blanked the recordings (stopped the paper roll) for 2 sec.
  • Reinforced on 'bursting', threshold sufficiently high that it only occurred once every 5-15 minutes.
  • Food reinforcement or 1/4 second train of brain stimulation (30ua, 60Hz, sine, in hypothalamus).
  • Reinforcement was conditioned on an 'acquisition' signal, which is visual (?) Bursting is rewarded for 2 minutes, ignored for 8 minutes.
  • Also recorded control neurons.
  • (they were looking at these things as though anew!) "The most striking aspect of the records so formed [on sheets of paper] was that all discriminators at one time or another exhibited rate changes that had the appearance of waves with a period of 10 to 20 minutes. Waves between units in the same animal were to some degree synchronized." Then describes a ramp ..
  • Longer term variations: FR would vary by a factor of 2-5 over a period of several hours.
    • This would make negatively correlated neurons (on a short time scale) appear positively correlated over long time scales (have to fix this in the BMI!)
  • As this was a conditional reinforcement task, they unexpectedly found that the acquisition periods were systematically different than extinction periods
    • More like pavlovian conditioning, esp in the hippocampus, where a conditioned response was also reflected on a control neuron.
    • Even when the light was lit throughout the acquisition period was replaced by a bell at the beginning of the acq. period, there was still a sustained change in FR.
      • Then during the extinction period: it appeared from the record of responses that a definite operant behavior was tried several times and then stopped altogether."
  • In the pontine nucleus (relay from M1 to cerebellum, v. roughly), judging from the control responses, all were conditioned.
    • Pontine responses seem to correspond with movement of the eyes or head that did not set off the movement detector/blanker.
  • Saw brief and very fast bursts during the extinction periods of the kind that Evarts found to characterize pyramical neurons during sleep.
  • When units shifted from food reward to ICS reward, units became undiffarentiated, and within a day they would be reconditioned.
  • Also tried paralyzing the animal to see if it could still generate operant responses; the animal died, results inconclusive.
  • Flood lights made it hard for the rats to produce the operant behavior.

____References____

[0] Olds J, The limbic system and behavioral reinforcement.Prog Brain Res 27no Issue 144-64 (1967)

{222}
hide / / print
ref: neuro notes-0 tags: clementine thesis electrophysiology fit predictions tlh24 date: 01-06-2012 03:07 gmt revision:4 [3] [2] [1] [0] [head]

ok, so i fit all timestamps from clem022007001 & timarm_log_070220_173947_k.mat to clementine's behavior, and got relatively low SNR for almost everything - despite the fact that I am most likely overfitting. (bin size = 7802 x 1491) the offset is calibrated @ 2587 ms + 50 to center the juice artifact in the first bin. There are 10 lags. There are 21 sorted units.

same thing, but with only the sorted units. juice prediction is, of course, worse.

now, for file clem022007002 & timarm_log_070220_175636_k.mat. first the unsorted:

and the sorted:

{925}
hide / / print
ref: Nicolelis-1997 tags: nicolelis microwire array electrophysiology rats date: 01-05-2012 03:35 gmt revision:2 [1] [0] [head]

PMID-9136763[0] Reconstructing the engram: simultaneous, multisite, many single neuron recordings.

  • descibes Miguel's microwire arrays.
  • 100 units from 48 microwires in rats.
  • 2.3 units / microwire.
  • stable for weeks -- c.f. 2011. [1]

____References____

[0] Nicolelis MA, Ghazanfar AA, Faggin BM, Votaw S, Oliveira LM, Reconstructing the engram: simultaneous, multisite, many single neuron recordings.Neuron 18:4, 529-37 (1997 Apr)
[1] Freire MA, Morya E, Faber J, Santos JR, Guimaraes JS, Lemos NA, Sameshima K, Pereira A, Ribeiro S, Nicolelis MA, Comprehensive analysis of tissue preservation and recording quality from chronic multielectrode implants.PLoS One 6:11, e27554 (2011)

{393}
hide / / print
ref: Sodagar-2007.06 tags: neural recording telemetry Wise Najafi mulitichannel electrophysiology Michigan ASIC date: 01-03-2012 23:07 gmt revision:4 [3] [2] [1] [0] [head]

PMID-17554826[0] A fully integrated mixed-signal neural processor for implantable multichannel cortical recording.

  • document is rich in details! looks pretty well designed, too.
  • Michigan 3-d electrodes
  • inductively powered, 2Mbps output
  • 64 channels
  • 18b/spike for 64 channels in scan mode, continuous waveforms on 2 channels in monitor mode
  • programmable analog spike detection. resolution: 5 bits.
  • no timestamps - send them out as they come in, with a clock rate fast enough so that this does not matter.
    • temporary storage in SRAM
    • time compression and buffering is somewhat complex (?)
  • only transmit threshold crossings, positive, negative, and both.
    • they do not detail how the signal is telemetered - perhaps this is for another publication.
  • fabricated chip occupies 3.5 x 2.7 mm. 0.5um process.
  • fabricated chip has a power of 200uw @ 1.8V. that's 6.4mW altogether! I need to get down to this figure! (well..)

____References____

{212}
hide / / print
ref: life-notes-2007 tags: electrode assay technology electrophysiology hack ad-hoc date: 01-03-2012 07:10 gmt revision:3 [2] [1] [0] [head]

properties of electrodes that are to penetrate the pia mater of a rhesus macaque:

  1. must easily go into a canned peach (in heavy or light sauce, it does not matter)
  2. does not go into pineapple cross-grain
  3. does go into the end-grain of pineapple
  4. penetrates the skin of a red grape (somewhat fresh) ~= pia
    1. The pia is a bit more tough than this, but is much less firm - if you are implanting electrodes that are any less than extremely sharp - e.g. etched - it will dimple the surface and not penetrate. Very sharp electrodes are key for getting through this tough membrane - which is even tougher in humans!
      • dimpling seems to silence cortical activity (observational evidence for this only)
      • however, once implanted lower-impedance electrodes work better. Low current microstimulation may be able to round the sharp tips of tungsten electrodes - we may want to test this.
    1. microdissection of the pia often damages the surface vasulature of the cortex, leading to localized infarctions, and hence should be avoided (unless you are really good)
    2. Bunching multiple elctrodes into one shaft - that is, making the shaft thicker and duller (albiet staggered) is not a good strategy for entering the brain (need to test the present monkeys).
  1. Cortical layer V (location of large pyramidal cells + betz cells in M1) in humans is 3-3.5mm below the surface, and ~1.6mm deep in rhesus. microwire/microwire arrays should have at least 2mm free wire length if intended for monkeys, and 4mm free wire if intended for humans.
    1. M1/S1 / central sulcus region is mostly inactive under isoflouro anesthesia, somewhat mangled/depressed with light ketamine, and silent with fentanyl. So, be careful with intraoperative recordings - the monkey/rat may be too deep, hence no cells to listen to!

{261}
hide / / print
ref: Aflalo-2007.03 tags: Graziano motor cortex M1 SUA macaque monkey electrophysiology tuning date: 01-03-2012 03:37 gmt revision:1 [0] [head]

PMID-17360898[] Relationship between Unconstrained Arm Movements and Single-Neuron Firing in the Macaque Motor Cortex

  • the best explanation of neuronal firing was the final mulijoint configuration of the arm - it accounted for 36% of the SUA variance.
  • the search for the 'correct' motor parameter (that neurons are tuned to) is an ill-posed experimental question because motor parameters are very intercorrelated.
  • they knock experiments in which the animals are overtrained & the movements limited - and they are right!
  • single electrode recording with cronically implanted steel chamber - e.g. it took a damn long time!
    • imaged the central sulcus through the dura.
    • verified location with single unit responses to palpation of the contralateral hand/arm (in S1) & microstimulation-evoked movements in M1.
  • used optotrak to measure the position of the monkey.
  • occasionally, the monkey attemptted to scratch the experimenter with fast semi-ballistic arm movement. heh. :)
  • movements were seprarated based on speed analysis - that is, all the data were analyzed as discrete segments.
  • neurons were inactive during periods of hand stasis between movements.
  • tested the diversity of their training set in a clever way: they simulated neurons tuned to various parameters of the motion, and tested to see if their analysis could recover the tuning. it could.
    • however, they still used unvalidated regression analysis to test their hypothesis. regression analysis estimates how much variance is estimated by the cosine-tuning model - it returns an R^2.
  • either averaged the neuronal tuning over an entire movement or smoothed the firing rate using a 10hz upper cutoff.
  • Moran & Schwartz' old result seems to be as much a consequence of averaging across trials as it is a consequence of actual tuning...
    • whithout the averaging, only 3% of the variance could be attributed to speed tuning.
  • i think that they have a good point in all of this: when you eliminate sources of variance (e.g. starting position) from the behavior, either by mechanical restraint or simple omission of segments or even better averaging over trials, you will get a higher R^2. but it may be false, a compression of the space along an axis where they are not well correlated!
  • a model in which the final position matters little, but the velocity used to get there does, has been found to account for little of the neuronal variance.
    • instead, neurons are tuned to any of a number of movements that terminate near a preferred direction.
  • observational studies of of the normal psontaneous behavior of monkeys indicate that a high proportion of time is spent using the arm as a postural device.
    • therefore, they expect that neurons are tuned to endpoint posture.
    • modeled the neuronal firing as a gaussian surface in the 8-dimensional space of the arm posture.
  • in comparison to other studies, the offset between neural activity and behavior was not significantly different, over the entire population of recorded neurons, from zero. This may be due to the nature of the task, which was spontaneous and ongoing, not cue and reaction based, as in many other studies.
    • quote: This result suggests that the neuronal tuning to posture reflects reatively more and anticipation of the future state of the limb rather than a feedback signal about a recent state of the limb.

____References____

{96}
hide / / print
ref: Moran-1999.11 tags: electrophysiology motor cortex Schwartz Moran M1 tuning date: 01-03-2012 03:36 gmt revision:2 [1] [0] [head]

PMID-10561437[0] Motor cortical representation of speed and direction during reaching

  • velocity is represented in the motor cortex.
  • they developed an equation relating firing rate to the position and velocity.
  • EMG direction had significantly different tuning from the cortical activity
    • the effect of speed on EMG was also different.
  • used single-electrode recording - 1,066 cells!!
  • introduce the square-root transformation of the firing rate (from Ashe and Georgopolous 1994)

____References____

{595}
hide / / print
ref: Fu-1993.11 tags: electrophysiology Ebner premotor motor tuning M1 date: 01-03-2012 03:34 gmt revision:1 [0] [head]

PMID-8294972 Neuronal specification of direction and distance during reaching movements in the superior precentral premotor area and primary motor cortex of monkeys. 1993

  • trained monkey to do center-out task, 48 targets (8 angles, 6 distances).
  • single-electrode recording of 197 neurons in the primary motor and secondary motor / premotor (in the superior precentral sulcus).
  • cells were mostly tuned to direction, and less to distance, in both the premovement and movement periods. distance tuning was much stronger in the movement period.
    • tuning was measure by average firing rate for the premovement, movement, and total periods.
  • long, very detailed!

{928}
hide / / print
ref: Kennedy-1989.09 tags: Kennedy neurotrophic electrode recording fabrication 1989 electrophysiology date: 01-03-2012 03:21 gmt revision:2 [1] [0] [head]

PMID-2796391[0] The cone electrode: a long-term electrode that records from neurites grown onto its recording surface.

  • A piece of the sciatic nerve is placed in the glass cone before implantation in the cortex of a rat.
  • A neurite can be an axon or dendrite.

____References____

[0] Kennedy PR, The cone electrode: a long-term electrode that records from neurites grown onto its recording surface.J Neurosci Methods 29:3, 181-93 (1989 Sep)

{150}
hide / / print
ref: Otto-2006.02 tags: electrophysiology recording rejuvenation stimulation MEA date: 01-03-2012 03:21 gmt revision:3 [2] [1] [0] [head]

PMID-16485763[0] Voltage pulses change neural interface properties and improve unit recordings with chronically implanted microelectrodes.

  • stimulation protocol: 1.5 volts, cortical electrode positive, 4 seconds, DC, current measured.
  • results: 10% mean improvement in SNR (not that great, oh well)
    • however, some effects were really profound: complete rejuvenation of the recordings!
  • result: 67% lower impedance.

____References____

[0] Otto KJ, Johnson MD, Kipke DR, Voltage pulses change neural interface properties and improve unit recordings with chronically implanted microelectrodes.IEEE Trans Biomed Eng 53:2, 333-40 (2006 Feb)

{960}
hide / / print
ref: -0 tags: M1 Evarts PTN conduction velocity monkey electrophysiology spinal cord date: 12-25-2011 04:25 gmt revision:0 [head]

PMID-14283057 Relation of Discharge Frequency to conduction velocity in pyramidal tract neurons

  • Not all PTN arise from the giant Betz cells -- there are too many pyramical tract axons, and not enough betz cells.
  • Most axons come from smaller cortical neurons [8,11,12].
  • Large cells have large axons hence the highest conduction velocity. (cite the squid studies...)
  • Estimate conduction velocity my stimulating in the medullary pyramid (e.g. the pyramidal tract at the level of the medulla)
  • Conduction velocity, in m/s, is six times diameter in microns (roughly; he lists no source here)
  • Mean frequency for 28 rapidly conductin units was 4.1 Hz;
    • These had a non-moving FR of fractional Hz.
    • Showed bursts with sleep, a few spikes when drowsy, very quiet when not moving.
  • MFR for 34 slower cells was 15.6 Hz.
    • Resting rate was higher in these cells.
    • Also showed bursts / more irregular firing with sleep.
  • Amazingly clean recordings. envy.
  • Some cells have much more irregular / more
  • Brookhart [2] concluded that large, rapidly conducting pyramidal fibers are probably responsible for the phasic element of movement control, whereas the smaller slower neurons are responsible for the tonic element.
  • Also true in the spinal cord: large afferents of the nuclear bag fibers in the muscle spindle carry transient info; group II are smaller and carry steady-state info.
  • ref Mountcastle [14] regarding reciprocal pairs of neurons being (surprise) reciprocally activated during joint movements.

{200}
hide / / print
ref: Nicolelis-1997.04 tags: nicolelis kralik electrodes electrophysiology 1997 date: 12-17-2011 01:41 gmt revision:3 [2] [1] [0] [head]

PMID-11812202[0] Techniques for long-term multisite neuronal ensemble recordings in behaving animals.

  • talk about moveable bundles.
  • human-level surgical techniques and anesthesia.
  • new methods of data analysis.

____References____

[0] Kralik JD, Dimitrov DF, Krupa DJ, Katz DB, Cohen D, Nicolelis MA, Techniques for long-term multisite neuronal ensemble recordings in behaving animals.Methods 25:2, 121-50 (2001 Oct)

{267}
hide / / print
ref: Kennedy-1992.08 tags: BMI Kennedy cone electrode electrophysiology recording neurotrophic date: 12-17-2011 01:00 gmt revision:1 [0] [head]

PMID-1407726[] The cone electrode: ultrastructural studies following long-term recording in rat and monkey cortex

  • they placed sciatic nerve inside the glass cone electrode to encourage regrowth.
    • alternatively, they filled the cone electrode with 'matrigel' whatever that 'neurotrophic substance' is.
  • good recordings at 6 months post impantation.
  • virtually no neurons were found in the tissue in any cone
    • however, they saw plenty of mylenated axons. (the mylenation assuredly is good for the quality of recordings hah)
    • in no case was the tissue absent from the glass.

____References____

{236}
hide / / print
ref: Kimura-1996.12 tags: putamen globus pallidus learning basal ganglia electrophysiology projection date: 10-03-2008 17:05 gmt revision:1 [0] [head]

PMID-8985875 Neural information transferred from the putamen to the globus pallidus during learned movement in the monkey.

  • study of the physiology of the projection from the striatum to the external and internal segments of the globus pallidus.
  • Identified neurons which project from the striatum to pallidus via antridromic activation after stim to the GPe / GPi.
  • there were two classes of striatal neurons:
    • tonically active neurons (TANs, rate: 4-8hz)
      • TANs were never activated by antidromic stimulation. therefore, they probably do not project to the pallidus.
    • phasically active neurons (very low basal rate, high frequency discharge in relation to behavioral tasks
      • All PANs found projected to the globus pallidus.
      • PANs were responsive to movement or movement preparation. (or not responsive to the particular behaviors investigated)
        • the PANns that showed activity before movement initiation more frequently projected to GPi and not GPE (or both - need to look at the anatomy more).
      • PANs also show bursts of activity time-locked to the initiation of movement (e.g. time locked to a particular part of the movement).
      • no neurons with sensory response!
  • when they microstimulated in the putamen, a few pallidal neurons showed exitatory response; most showed inhibitory/supressive response.

{104}
hide / / print
ref: Boline-2005.11 tags: electrophysiology motor cortex force isometric Ashe 2005 date: 04-09-2007 22:39 gmt revision:3 [2] [1] [0] [head]

this seems to be the same as {339}, with a different pubmed id & different author list. bug in the system!

PMID-16193273[0] On the relations between single cell activity in the motor cortex and the direction and magnitude of three-dimensional dynamic isometric force* the majority of cells responded to direction

  • few to the magnitude,
  • and ~10% to the direction & magnitude
  • control of static and dynamic motor systems is based on a common control process!
  • 2d task, monkeys, single-unit recording, regression analysis.

____References____

{338}
hide / / print
ref: Ashe-1994.12 tags: Georgoplous motor control M1 S1 SUA electrophysiology 2D date: 04-09-2007 20:27 gmt revision:2 [1] [0] [head]

PMID-7703686[0] Movement parameters and neural activity in motor cortex and area 5

  • 290 cells in the motor cortex and 207 cells in area 5 (S1)
  • median R^2 = 0.581 & 0.530 in motor cortex
  • most prominent representation of target direction; least prominent representation of acceleration. (though statistically significant correlations were observed for all behavioral parameters)

Duke does not have online access to the article :(

____References____

{345}
hide / / print
ref: HeppReymond-1999.09 tags: force motor control grip electrophysiology date: 04-09-2007 20:20 gmt revision:0 [head]

PMID-10473750[0] Context-dependent force coding in motor and premotor cortical areas.

  • here they found neurons related to dF/dt during another isometric precision grip task.

____References____

{286}
hide / / print
ref: Maier-1993.03 tags: force motor control grip electrophysiology date: 04-09-2007 20:20 gmt revision:4 [3] [2] [1] [0] [head]

PMID-8463818[0] Contribution of the monkey corticomotoneuronal system to the control of force in precision grip

  • recorded 33 corticomotoneronal cells
  • used spike-triggered averaging to find putative pyramidal tract neurons.
  • considerable trail-by-trial variability in the cells activity-force relationship
  • and, in an earlier work: PMID-810360[1] Relation of activity in precentral cortical neurons to force and rate of force change during isometric contractions of finger muscles.

____References____

{152}
hide / / print
ref: Amirikian-2000.01 tags: Georgopulos directional tuning motor cortex SUA electrophysiology date: 04-05-2007 16:34 gmt revision:2 [1] [0] [head]

PMID-10678534[0] Directional tuning profiles of motor cortical cells

  • trained the monkeys to move to 20 targets in a horizontal plane
    • the larger number of targets allowed a more accurate estimation of the tuning properties of the cells
    • measured tuning based on the spike count during movement.
  • typical r^2 = 0.7 for a modified cosine fit

____References____

{198}
hide / / print
ref: Teich-1997.03 tags: fractal LGN RGC electrophysiology SUA fano_factor date: 02-05-2007 19:00 gmt revision:0 [head]

PMID-9058948[0] Fractal character of the neural spike train in the visual system of the cat

  • excellent description of several analyses of point-process spike trains (here RGC and LGN cells): interevent-interval histogram, rescaled range analysis, the event-number histogram, the Fano factor, the Allan factor, and the periodogram.

http://hardcarve.com/wikipic/Teich1997_fanofactor.gif

____References____

{197}
hide / / print
ref: Afanasev-2004.03 tags: striatum learning reinforcement electrophysiology putamen russians date: 02-05-2007 17:33 gmt revision:3 [2] [1] [0] [head]

PMID-15151178[0] Sequential Rearrangements of the Ensemble Activity of Putamen Neurons in the Monkey Brain as a Correlate of Continuous Behavior

  • recorded 6-7 neurons in the putamen during alternative spatial selection
  • used discriminant analysis (whats that?) to analyze re-arrangements in spike activity
  • dynamics of re-arrangnement were dependent on reinforcement, and mostly contralateral striatum

____References____

{157}
hide / / print
ref: Ito-2003.1 tags: anterior cingulate cortex ACC electrophysiology date: 0-0-2007 0:0 revision:0 [head]

PMID-14526085 Performance Monitoring by the Anterior Cingulate Cortex During Saccade Countermanding

locations of neurons http://www.sciencemag.org/content/vol302/issue5642/images/large/se3831902004.jpeg

{118}
hide / / print
ref: Cooper-2000.09 tags: globus pallidus electrophysiology current clamp channel date: 0-0-2007 0:0 revision:0 [head]

PMID-10970430 Electrophysiological and morphological characteristics of three subtypes of rat globus pallidus neurone in vitro

  • there are 3 morphological types of neurons.
    • A: inward rectfier + low-threshold calcium current = anode break depolarizations.
    • B: no inward rectifier, just fast monophasic AHP. small.
    • C: big! (...)

{117}
hide / / print
ref: Gdowski-2001.02 tags: globus pallidus reward electrophysiology 2001 date: 0-0-2007 0:0 revision:0 [head]

PMID-11160530 Context Dependency in the Globus Pallidus Internal Segment During Targeted Arm Movements

  • most of the movement-responsive neurons had modulations in the cued segment of the task, not in the subsequent relaxed, self-paced phase.
  • this constitutes a reward or context-dependence.
{116}

{153}
hide / / print
ref: Stefani-1995.09 tags: electrophysiology dopamine basal_ganglia motor learning date: 0-0-2007 0:0 revision:0 [head]

PMID-8539419 Electrophysiology of dopamine D-1 receptors in the basal ganglia: old facts and new perspectives.

  • D1 is inhibitory (modulatory) on striatal neurons.
  • D1 cloned in 1990
  • D1 stimulates adenyl cyclase. (cAMP)
  • D1 activity shown to be necessary, but not sufficient, to generate long-term depression in striatal slices.
  • SKF 38393 was designed as a selective D1 receptor agonist; it has been available since the late 70's; it has nanomolar affinity for D1-R. SKF 38393 inhibits action potential discharge in striatal neurons as measued through response to intracellular current depolarizations.
  • striatal cells project to the substantia nigra.
  • alternate hypothesis: D1 activation on the striatonigral afferents to the ventral tegmental area (VTA) promotes GABA release.
    • recall that the VTA projects to the frontal/prefrontal cortex (PFC) via the mesocortical dopiminergic pathway. http://grad.uchc.edu/phdfaculty/antic.html There, DA synapese on spines of distal dendrites in juxtaposition with glutamergic synapses. this guy posits that these DA synapses are involved in the pathology of schizophrenia, and he uses optical techniques to measure the DA/Glu synapses.
    • VTA is just below the red nucleus in rats.
  • some people report that SKF 38393 potentiated depolarizing membrane responses to exogenous NMDA (agonist, excitotoxin).
  • they prefer the magnesium-dependent LTD pathway.
    • D1 receptor antagonist SCH 23390 prevented the generation of LTD in striatum. (Calabresi et al 1992).
    • in DA-depleted slices, LTD could be restored by the co-administration of D1 and D2 agonists.

{155}
hide / / print
ref: Wannier-2002.01 tags: globus_pallidus electrophysiology caudate putamen basal_ganglia date: 0-0-2007 0:0 revision:0 [head]

PMID-11924876 Neuronal activity in primate striatum and pallidum related to bimanual motor actions

  • monkeys had to pull on a spring-loaded drawer and grab food with other hand.
  • half the recorded neurons were responsive to this task.
  • targeted: 20.1 to 14.v mm anterior to the interaural plane of the rhesus monkey brain.
    • 19.2 mm looks good for GPe
    • 17.4 for putamen and caudate (right below area 24 in the cortex - Ventral cingulate cortex)
    • 15.6 for putamen, GPe, and GPi.
  • can these be modulated by imagined movement? e.g. in a BMI?