m8ta
You are not authenticated, login.
text: sort by
tags: modified
type: chronology
[0] Fetz EE, Perlmutter SI, Prut Y, Functions of mammalian spinal interneurons during movement.Curr Opin Neurobiol 10:6, 699-707 (2000 Dec)

[0] Nishida M, Walker MP, Daytime naps, motor memory consolidation and regionally specific sleep spindles.PLoS ONE 2:4, e341 (2007 Apr 4)

[0] Tamaki M, Matsuoka T, Nittono H, Hori T, Fast sleep spindle (13-15 hz) activity correlates with sleep-dependent improvement in visuomotor performance.Sleep 31:2, 204-11 (2008 Feb 1)

[0] Morin A, Doyon J, Dostie V, Barakat M, Hadj Tahar A, Korman M, Benali H, Karni A, Ungerleider LG, Carrier J, Motor sequence learning increases sleep spindles and fast frequencies in post-training sleep.Sleep 31:8, 1149-56 (2008 Aug 1)

[0] Allman JM, Hakeem A, Erwin JM, Nimchinsky E, Hof P, The anterior cingulate cortex. The evolution of an interface between emotion and cognition.Ann N Y Acad Sci 935no Issue 107-17 (2001 May)

[0] Sabelli HC, Mosnaim AD, Vazquez AJ, Giardina WJ, Borison RL, Pedemonte WA, Biochemical plasticity of synaptic transmission: a critical review of Dale's Principle.Biol Psychiatry 11:4, 481-524 (1976 Aug)[1] Sulzer D, Rayport S, Dale's principle and glutamate corelease from ventral midbrain dopamine neurons.Amino Acids 19:1, 45-52 (2000)[2] Burnstock G, Do some nerve cells release more than one transmitter?Neuroscience 1:4, 239-48 (1976 Aug)

{1417}
hide / / print
ref: -0 tags: synaptic plasticity 2-photon imaging inhibition excitation spines dendrites synapses 2p date: 08-14-2020 01:35 gmt revision:3 [2] [1] [0] [head]

PMID-22542188 Clustered dynamics of inhibitory synapses and dendritic spines in the adult neocortex.

  • Cre-recombinase-dependent labeling of postsynapitc scaffolding via Gephryn-Teal fluorophore fusion.
  • Also added Cre-eYFP to label the neurons
  • Electroporated in utero e16 mice.
    • Low concentration of Cre, high concentrations of Gephryn-Teal and Cre-eYFP constructs to attain sparse labeling.
  • Located the same dendrite imaged in-vivo in fixed tissue - !! - using serial-section electron microscopy.
  • 2230 dendritic spines and 1211 inhibitory synapses from 83 dendritic segments in 14 cells of 6 animals.
  • Some spines had inhibitory synapses on them -- 0.7 / 10um, vs 4.4 / 10um dendrite for excitatory spines. ~ 1.7 inhibitory
  • Suggest that the data support the idea that inhibitory inputs maybe gating excitation.
  • Furthermore, co-inervated spines are stable, both during mormal experience and during monocular deprivation.
  • Monocular deprivation induces a pronounced loss of inhibitory synapses in binocular cortex.

{1494}
hide / / print
ref: -2014 tags: dopamine medium spiny neurons calcium STDP PKA date: 01-07-2020 03:43 gmt revision:2 [1] [0] [head]

PMID-25258080 A critical time window for dopamine actions on the structural plasticity of dendritic spines

  • Remarkably short time window for dopamine to modulate / modify (aggressive) STDP protocol.
  • Showed with the low-affinity calcium indicator Fluo4-FF that peak calcium concentrations in spines is not affected by optogenetic stimulation of dopamine fibers.
  • However, CaMKII activity is modulated by DA activity -- when glutamate uncaging and depolarization was followed by optogenetic stimulation of DA fibers followed, the FRET sensor Camui-CR reported significant increases of CaMKII activity.
  • This increase was abolished by the application of DRAPP-32 inhibiting peptide, which blocks the interaction of dopamine and cAMP-regulated phospoprotein - 32kDa (DRAPP-32) with protein phosphatase 1 (PP-1)
    • Spine enlargement was induced in the absence of optogenetic dopamine when PP-1 was inhibited by calculin A...
    • Hence, phosphorylation of DRAPP-32 by PKA inhibits PP-1 and disinihibts CaMKII. (This causal inference seems loopy; they reference a hippocampal paper, [18])
  • To further test this, they used a FRET probe of PKA activity, AKAR2-CR. This sensor showed that PKA activity extends throughout the dendrite, not just the stimulated spine, and can respond to DA release directly.

{1394}
hide / / print
ref: -0 tags: Courtine PDMS soft biomaterials spinal cord e-dura date: 12-22-2017 01:29 gmt revision:0 [head]

Materials and technologies for soft implantable neuroprostheses

  • Quote: In humans, both the spinal cord and its meningeal protective membranes can experience as much as 10–20% tensile strain and
displacement (relative to the spinal canal) during normal postural movements. This motion corresponds to displacements on the order of centimetres17. The deformations relative to the spinal cord in animal models, such as rodents or non-human primates, are likely to be even larger.

{1378}
hide / / print
ref: -0 tags: carbon fiber thread spinning Pasquali Kemere nanotube stimulation date: 02-09-2017 01:09 gmt revision:0 [head]

PMID-25803728 Neural stimulation and recording with bidirectional, soft carbon nanotube fiber microelectrodes.

  • Poulin et al. demonstrated that microelectrodes made solely of CNT fibers22 show remarkable electrochemical activity, sensitivity, and resistance to biofouling compared to conventional carbon fibers when used for bioanalyte detection in vitro.23-25
  • Fibers were insulated with 3 um of block copolymer polystyrene-polybutadiene (PS-b-PBD) (polybutadiene is sythetic rubber)
    • Selected for good properties of biocompatibility, flexibility, resistance to flextural fatigue.
    • Available from Sigma-Aldrich.
    • Custom continuous dip-coating process.
  • 18um diameter, 15 - 20 x lower impedance than equivalently size PtIr.
    • 2.5 - 6x lower than W.
    • In practice, 43um dia, 1450um^2, impedance of 11.2 k; 12.6um, 151k.
  • Charge storage capacity 327 mC / cm^2; PtIr = 1.2 mC/cm^2
  • Wide water window of -1.5V - 1.5V, consistent with noble electrochemical properties of C.
  • Lasts for over 97e6 pulsing cycles beyond the water window, vs 43e6 for PEDOT.
  • Tested via 6-OHDA model of PD disease vs. standard PtIr stimulating electrodes, implanted via 100um PI shuttled attached with PEG.
  • Yes, debatable...
  • Tested out to 3 weeks durability. Appear to function as well or better than metal electrodes.

PMID-23307737 Strong, light, multifunctional fibers of carbon nanotubes with ultrahigh conductivity.

  • Full process:
    1. Dissolve high-quality, 5um long CNT in chlorosulfonic acid (the only known solvent for CNTs)
    2. Filter to remove particles
    3. Extrude liquid crystal dope through a spinneret, 65 or 130um orifice
    4. Into a coagulant, acetone or water
    5. Onto a rotating drum to put tension on the thread & align the CNTs.
    6. Wash in water and dry at 115C.
  • Properties:
    • Tensile strength 1 GPa +- 0.2 GPa.
    • Tensile modulus 120 GPa +- 50, best value 200 GPa
      • Pt: 168 GPa ; Au: 79 GPa.
    • Elongation to break 1.4 %
    • Conductivity: 0.3 MS/m, Iodine doped 5 +- 0.5 MS/m (22 +- 4 microhm cm)
      • Cu: 59.6 MS/m ; Pt: 9.4 MS/m ; Au: 41 MS/m
      • Electrical conductivity drops after annealing @ 600C
      • But does not drop after kinking and repeated mechanical cycling.
  • Theoretical modulus of MWCNT ~ 350 GPa.
  • Fibers well-aligned at ~ 90% the density (measure 1.3 g/cc) of close-packed CNT.

{1360}
hide / / print
ref: -0 tags: L1 cell adhesion neural implants microglia DRG spinal cord dorsal root inflammation date: 11-19-2016 22:55 gmt revision:1 [0] [head]

PMID-22750248 In vivo effects of L1 coating on inflammation and neuronal health at the electrode-tissue interface in rat spinal cord and dorsal root ganglion.

  • Kolarcik CL1, Bourbeau D, Azemi E, Rost E, Zhang L, Lagenaur CF, Weber DJ, Cui XT.
  • Quote: With L1, neurofilament staining was significantly increased while neuronal cell death decreased.
  • These results indicate that L1-modified electrodes may result in an improved chronic neural interface and will be evaluated in recording and stimulation studies.
  • Ok, so this CAM seems to mitigate against microglia / inflammation, but how was it selected vs any of the other CAMs and surface proteins? (This domain is almost completely unknown by me..)
  • Ultimate strategy likely to be a broad combination of mechanical (size, flexibility), biochemical (inflammation, cell migration), electrochamical (surface coatings) and vasculature-avoiding approaches.

{1313}
hide / / print
ref: -0 tags: Kewame carbon nanotube yarn wet spinning CNT date: 03-26-2015 18:29 gmt revision:0 [head]

Neural Stimulation and Recording with Bidirectional, Soft Carbon Nanotube Fiber Microelectrodes

  • 43um diameter CTN yarn
  • Shows superior charge injection / surface area.
  • polystyrene-polybutadiene co-polymer insulation (like ABS, without the acrylonitrile)
  • https://chemistry.beloit.edu/classes/nanotech/CNT/nanotoday3_5_24.pdf -- details on the process of spinning these CNT yarns.
    • Tensile strength still far below commercial carbon fibers or high-strength polymers.

{748}
hide / / print
ref: Leung-2008.08 tags: biocompatibility alginate tissue response immunochemistry microglia insulation spin coating Tresco recording histology MEA date: 01-28-2013 21:19 gmt revision:4 [3] [2] [1] [0] [head]

PMID-18485471[0] Characterization of microglial attachment and cytokine release on biomaterials of differing surface chemistry

  • The important result is that materials with low protein-binding (e.g. alginate) have fewer bound microglia, hence better biocompatibility. It also seems to help if the material is highly hydrophilic.
    • Yes alginate is made from algae.
  • Used Michigan probes for implantation.
  • ED1 = pan-macrophage marker.
    • (quote:) Quantification of cells on the surface indicated that the number of adherent microglia appeared higher on the smooth side of the electrode compared to the grooved, recording site side (Fig. 2B), and declined with time. However, at no point were electrodes completely free of attached and activated microglial cells nor did these cells disappear from the interfacial zone along the electrode tract.
    • but these were not coated with anything new .. ???

____References____

[0] Leung BK, Biran R, Underwood CJ, Tresco PA, Characterization of microglial attachment and cytokine release on biomaterials of differing surface chemistry.Biomaterials 29:23, 3289-97 (2008 Aug)

{991}
hide / / print
ref: Fuentes-2009.03 tags: Nicoelis DCS spinal cord stimulation PD Fuentes Petersson 6-OHDA date: 03-03-2012 02:46 gmt revision:3 [2] [1] [0] [head]

PMID-19299613[0] Spinal cord stimulation restores locomotion in animal models of Parkinson's disease.

  • Motivation: different levels of cortical oscillation during movement and rest (LFO decreased, medium-high freq increased); PD associated with abnormal synchronous corticostriatal oscillations.
  • In epilepsy patients, stimulation of peripheral nerve afferents is effective in desychronizing low-frequency neural activity, reducing the frequency and duration of seizures (8,9,10) PMID-11050139[1] PMID-16886985[2] PMID-18188148[3]
  • DCS (dorsal column stimulation)
    • Epidural, longitudal electrodes, horizontal electrical field.
    • Upper thoracic, mice.
    • 300Hz.
    • simpler and safer than brain surgery.
    • [24] DCS induces no increase in arousal. (Wall, PD. Brain 1970; 93:505.
  • used the tyrosine hydroxyalse inhibitor AMPT
  • M1 LFP: Osc around 1.5-4Hz and 10-15Hz enhanced; osc > 25Hz subdued.
  • DCS increased locomotion by 29x in depleted animals, and 4.9x in normal animals.
  • Also titrated L-DOPA with DAT-KO mice. Without dopamine, there is no movement.
    • DCS increased L-DOPA effectiveness by 5x (1/5 the dose was required)
  • Verified in a 6-OHDA lesion model in rats.
    • Lesioned animals moved more, sham moved less.
  • Activation of locomotion is via striatal medium spiny neurons projecting to the output nuclei of the basal ganglia [26 PMID-8402406[4] ,27 PMID-1695404[5]].
  • In PD, with reduced striatal dopamine levels, the activation threshold of the projection neurons from the striatum is significantly increased [25] PMID-17916382[6].

____References____

[0] Fuentes R, Petersson P, Siesser WB, Caron MG, Nicolelis MA, Spinal cord stimulation restores locomotion in animal models of Parkinson's disease.Science 323:5921, 1578-82 (2009 Mar 20)
[1] Fanselow EE, Reid AP, Nicolelis MA, Reduction of pentylenetetrazole-induced seizure activity in awake rats by seizure-triggered trigeminal nerve stimulation.J Neurosci 20:21, 8160-8 (2000 Nov 1)
[2] DeGiorgio CM, Shewmon A, Murray D, Whitehurst T, Pilot study of trigeminal nerve stimulation (TNS) for epilepsy: a proof-of-concept trial.Epilepsia 47:7, 1213-5 (2006 Jul)
[3] George MS, Nahas Z, Bohning DE, Lomarev M, Denslow S, Osenbach R, Ballenger JC, Vagus nerve stimulation: a new form of therapeutic brain stimulation.CNS Spectr 5:11, 43-52 (2000 Nov)
[4] Brudzynski SM, Wu M, Mogenson GJ, Decreases in rat locomotor activity as a result of changes in synaptic transmission to neurons within the mesencephalic locomotor region.Can J Physiol Pharmacol 71:5-6, 394-406 (1993 May-Jun)
[5] DeLong MR, Primate models of movement disorders of basal ganglia origin.Trends Neurosci 13:7, 281-5 (1990 Jul)
[6] Grillner S, Wallén P, Saitoh K, Kozlov A, Robertson B, Neural bases of goal-directed locomotion in vertebrates--an overview.Brain Res Rev 57:1, 2-12 (2008 Jan)

{1149}
hide / / print
ref: -0 tags: locomotion decerebrated monkeys spinal cord section STN stimulation date: 03-01-2012 23:53 gmt revision:0 [head]

PMID-7326562 Locomotor control in macaque monkeys

  • Were not able to induce walking with in monkeys with a sectioned spinal cord
  • Were able to induce walking motion by pulsed stimulation of the STN, with varying walking speed with varying currents!
  • Detailed, informative report, more than I have time to record here today.

{1066}
hide / / print
ref: Hagbarth-1983.02 tags: piper rhythm oscillations feedback proprioception spinal reflex date: 01-19-2012 21:41 gmt revision:2 [1] [0] [head]

PMID-6869036[0] The Piper rhythm--a phenomenon related to muscle resonance characteristics?

  • Piper rhythm: the tendency towards rhytmical 40-60 Hz grouping of motor unit potentials in steadily contracting human muscles.
  • Recording of nerves in muscles did not support the idea that the Piper rhythm is dependent on afferent spindle pulses causing reflex entrainment. (loop too slow).
  • TThis wouldn't make sense anyway, as the same rhythm appears in different muscles with markedly different mechanical properties.
  • Likkely cause is the cerebrum, upper oscillations. Interesting!
  • See also: PMID-9862895[1] Cortical correlate of the Piper rhythm in humans.
    • MEG data is consistent with the cortex being the origin of the Piper rhythm.
  • And PMID-10203308[2] Rhythmical corticomotor communication.
    • The rhythmic modulation may form a tool for efficient driving of motor units but we express some reservations about the assumed binding and attention-related roles of the rolandic brain rhythms.
  • PMID-10622378[3] Cortical drives to human muscle: the Piper and related rhythms.
    • Alternately, oscillations may be a form of holding state.
    • They think gamma frequencies are a means of binding together simultaneously activated isometric muscles.
    • Inadequate output from the basal ganglia leads to a disappearance of the beta and piper drives to muscle.
    • Did we see and piper band osc activity? Did not look.

____References____

[0] Hagbarth KE, Jessop J, Eklund G, Wallin EU, The Piper rhythm--a phenomenon related to muscle resonance characteristics?Acta Physiol Scand 117:2, 263-71 (1983 Feb)
[1] Brown P, Salenius S, Rothwell JC, Hari R, Cortical correlate of the Piper rhythm in humans.J Neurophysiol 80:6, 2911-7 (1998 Dec)
[2] Hari R, Salenius S, Rhythmical corticomotor communication.Neuroreport 10:2, R1-10 (1999 Feb 5)
[3] Brown P, Cortical drives to human muscle: the Piper and related rhythms.Prog Neurobiol 60:1, 97-108 (2000 Jan)

{933}
hide / / print
ref: Moritz-2008.12 tags: FES BMI Fetz Moritz Perlmutter spinal cord date: 01-08-2012 05:18 gmt revision:1 [0] [head]

PMID-18923392[0] Direct control of paralysed muscles by cortical neurons.

  • FES BMI: route signals around a broken spinal cord.
  • Found that "neurons could control functional stimulation equally well regardless of any prior association to movement". interesting. consistent with previous work. Wonder if I can duplicate this result.
  • Another relatively straightforward (?) paper where most of the difficulty is technology (!!). I mean, what new knowledge was needed to do this? Compare this with the technology that was needed. One of these was very challenging. now, as it come in for my stuff: what does technology let you do? Have to motivate.

____References____

[0] Moritz CT, Perlmutter SI, Fetz EE, Direct control of paralysed muscles by cortical neurons.Nature 456:7222, 639-42 (2008 Dec 4)

{288}
hide / / print
ref: Fetz-2000.12 tags: motor control spinal neurons interneurons movement primitives Fetz review tuning date: 01-03-2012 23:08 gmt revision:4 [3] [2] [1] [0] [head]

PMID-11240278[0] Functions of mammalian spinal interneurons during movement

  • this issue of current opinion in neuro has many reviews of motor control
  • points out that the Bizzi results (they microstimulated & observed a force-field-primitive type organization)
    • others have found that this may be a consequence of decerebration + the structure of the biomechanical groupings of muscles. (see 'update').
  • intraspinal electrodes in the cat provide a secure and reliable method of eliciting forces and movements.
  • CM (corticomotor) cells more often represent synergistic groups of muscles, whereas premotor spinal interneurons are organized to target specific muscles.
    • CMs are therefore more strictly recruited for particular movements.
  • interneurons (IN) are, of course, arrayed in such a way so that antagonist and agonist muscles cross-inhibit eachother (for efficiency)
    • however, we are still able to control the endpoint impedance of the arm - how?
  • spinal interneurons modulate activity during wait period prior to movement!
    • there might be substantial interaction between the cortex and spinal cord.. subjects asked to imagine pressing a foot pedal showed enhanced reflexes in the involved soleus muscle.
      • cognitive priming?
  • spinal reflexes are strongly modulated in movement.

____References____

{893}
hide / / print
ref: Grutzendler-2011.09 tags: two-photon imaging in-vivo neurons recording dendrites spines date: 01-03-2012 01:02 gmt revision:3 [2] [1] [0] [head]

PMID-21880826[0] http://cshprotocols.cshlp.org/content/2011/9/pdb.prot065474.full?rss=1

  • Excellent source of information and references. Go CSH!
  • Possible to image up to 400um deep. PMID-12490949[1]
  • People have used TPLSM imaging for years in mice. PMID-19946265[2]

____References____

[0] Grutzendler J, Yang G, Pan F, Parkhurst CN, Gan WB, Transcranial two-photon imaging of the living mouse brain.Cold Spring Harb Protoc 2011:9, no Pages (2011 Sep 1)
[1] Grutzendler J, Kasthuri N, Gan WB, Long-term dendritic spine stability in the adult cortex.Nature 420:6917, 812-6 (2002 Dec 19-26)
[2] Yang G, Pan F, Gan WB, Stably maintained dendritic spines are associated with lifelong memories.Nature 462:7275, 920-4 (2009 Dec 17)

{942}
hide / / print
ref: Thevathasan-2010.04 tags: DCS DBS spinal cord stimulation PD date: 12-28-2011 20:43 gmt revision:4 [3] [2] [1] [0] [head]

PMID-20404313[0] Spinal cord stimulation failed to relieve akinesia or restore locomotion in Parkinson disease.

  • motivated by [1]
  • Implanted two PD patients with commercial DBS stimulators and electrodes; observed no therapeutic effect.
  • Electric field was axial rather than transverse, hence likely did not activate the same way or same ammount as in the Nicolelis study.
  • Not sure if anyone has tried with other eletrodes... spinal cord stimulation would be great for inductive powering.

____References____

[0] Thevathasan W, Mazzone P, Jha A, Djamshidian A, Dileone M, Di Lazzaro V, Brown P, Spinal cord stimulation failed to relieve akinesia or restore locomotion in Parkinson disease.Neurology 74:16, 1325-7 (2010 Apr 20)
[1] Fuentes R, Petersson P, Siesser WB, Caron MG, Nicolelis MA, Spinal cord stimulation restores locomotion in animal models of Parkinson's disease.Science 323:5921, 1578-82 (2009 Mar 20)

{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.

{712}
hide / / print
ref: MAPlle-2009.03 tags: sleep spindles learning ripples LFP hippocampus neocortex synchrony SWS REM date: 03-25-2009 15:05 gmt revision:2 [1] [0] [head]

PMID-19245368[0] The influence of learning on sleep slow oscillations and associated spindles and ripples in humans and rats

  • Here we examined whether slow oscillations also group learning-induced increases in spindle and ripple activity, thereby providing time-frames of facilitated hippocampus-to-neocortical information transfer underlying the conversion of temporary into long-term memories.
  • No apparent grouping effect between slow oscillations and learning-induced spindles and ripples in rats.
  • Stronger effect of learning on spindles (neocortex) and ripples (hippocampus) ; less or little effect of learning on slow waves in the neocortex.
  • have a good plot showing their time-series analysis:

____References____

[0] Mölle M, Eschenko O, Gais S, Sara SJ, Born J, The influence of learning on sleep slow oscillations and associated spindles and ripples in humans and rats.Eur J Neurosci 29:5, 1071-81 (2009 Mar)

{701}
hide / / print
ref: Rasch-2009.04 tags: REM learning procedural memory sleep spindles date: 03-23-2009 18:32 gmt revision:3 [2] [1] [0] [head]

PMID-18836440[0] Pharmacological REM sleep suppression paradoxically improves rather than impairs skill memory

  • surpressed REM sleep with SSRIs or norepinephrine reuptake inhibitor
    • yet tested the subjects after a long wash-out: 32 hours, including 2 nights sleep.
  • did not impair word-pair recognition, and improved finger tapping accuracy.
  • sleep spindles are a feature of non-REM sleep.
  • REM sleep is characterized by an abscence of serotonin and norepinephrine; SSRIs and SNRIs increase the levels of these two neurotransmitters, respectively, at the synaptic cleft.
  • clinical studies of depressed patients show no impairment of skill performance during long-term treatment with these drugs, despite marked REM supression
  • did mirror-tracing and finger-tapping tasks.
  • SSRI supressed REM sleep; SNRI almost completely removed REM.
  • treatment increased accuracy of finger tapping task! esp. for the SNRI.
    • increase in accuracy was positively correlated to the change in spindle density.
  • For the mirror task, there were notable improvements after sleep, but no significant difference between placebo, SSRI, and SNRI groups.
  • paired-word retention task has been shown dependent on SWS; it was not affected by pharmacology.
  • They suggest that perhaps SSRI /SNRI supressed simply the typical measures of REM sleep, and that other factors critical for the associated consolidation were unaffected (e.g. high cholinergic activity).
  • result is consistent with [1]

____References____

[0] Rasch B, Pommer J, Diekelmann S, Born J, Pharmacological REM sleep suppression paradoxically improves rather than impairs skill memory.Nat Neurosci no Volume no Issue no Pages (2008 Oct 5)
[1] Tamaki M, Matsuoka T, Nittono H, Hori T, Fast sleep spindle (13-15 hz) activity correlates with sleep-dependent improvement in visuomotor performance.Sleep 31:2, 204-11 (2008 Feb 1)

{703}
hide / / print
ref: Eschenko-2006.12 tags: sleep spindle learning rats date: 03-20-2009 00:40 gmt revision:1 [0] [head]

PMID-17167082[0] Elevated sleep spindle density after learning or after retrieval in rats.

  • sleep spindles = 12–15 Hz oscillations superimposed on slow waves (<1 Hz)
    • they say these 'promote' but infact they may just be effects of some lower-level synchronization / ensemble depolarization.
  • used an odor-response-reward task.
  • spindles reliably appear 1 hour after sleep begins.
  • hippocampal ripples are temporally related to cortical spindles and both are grouped by slow oscillations.
  • showed that pure exploration of novel environments (without the odorant pairing) does not change sleep spindle occurence frequency.

____References____

[0] Eschenko O, Mölle M, Born J, Sara SJ, Elevated sleep spindle density after learning or after retrieval in rats.J Neurosci 26:50, 12914-20 (2006 Dec 13)

{680}
hide / / print
ref: Nishida-2007.04 tags: sleep spindle learning nap NREM date: 03-06-2009 17:56 gmt revision:1 [0] [head]

PMID-17406665[0] Daytime naps, motor memory consolidation and regionally specific sleep spindles.

  • asked subjects to learn a motor task with their non-dominant hand, and then tested them 8 hours later.
  • subjects that were allowed a 60-90 minute siesta improved their performance significantly relative to controls and relative to previous performance.
  • when they subtracted EEG activity of the non-learning hemisphere from the learning hemisphere, spindle activity was strongly correlated with offline memory improvement.

____References____

{679}
hide / / print
ref: Tamaki-2008.02 tags: sleep spindle NREM motor learning date: 02-18-2009 17:44 gmt revision:0 [head]

PMID-18274267[0] Fast sleep spindle (13-15 hz) activity correlates with sleep-dependent improvement in visuomotor performance.

  • mirror-tracing task performance improves following a night's sleep.
  • the improvement is correlated with the fast-spindle activity.
  • spindles were detected from EEG recordings with a 10-16hz butterworth filter in matlab. Spindles had to be >= 15uv, >= 0.5s
    • slow spindles = 10-13Hz, predominant in the frontal regions.
    • fast spindles > 13hz, predominant in the parietal regions.

____References____

{672}
hide / / print
ref: Morin-2008.08 tags: sleep spindles NREM motor learning date: 02-18-2009 17:35 gmt revision:2 [1] [0] [head]

PMID-18714787[0] Motor sequence learning increases sleep spindles and fast frequencies in post-training sleep.

  • as you can read in the title, it is the motor learning that increases the spindles. They did not look for causality in the opposite direction.
  • Task was finger-tap motor sequence learning, with control. Subjects had to type on a computer keyboard using the nondominant hand. No visual feedback was given during non-training performance (e.g. during practice).
  • Beta-frequencies are greater in sleep after motor learning. , though this is not correlated with actual consolidation.
  • Other studies have shown that spindles are also more frequent after spatial or verbal learning.
  • observed no effect of SWS on motor sequence learning.

____References____

{655}
hide / / print
ref: Allman-2001.05 tags: anterior cingulate dopamine spindle neurons review date: 12-15-2008 04:13 gmt revision:1 [0] [head]

PMID-11411161[0] The anterior cingulate cortex. The evolution of an interface between emotion and cognition

  • The ACC receives one of the riches dopaminergic innervations of any cortical area.
  • The ACC contains morphologically distinct spindle cells, a recent advance in hominid evolution. (Appears that they are also present in monkeys, since people can perform experiments there too).
  • A large body of EEG data indicates that the anterior cingulate is the source of a 4- to 7-Hertz signal present when the subject is performing a task requiring focused concentration.24 The amplitude of this signal increases with task difficulty.25 When the subject is restless and anxious, the signal is reduced or eliminated; when the anxiety is relieved with drugs, the signal is restored.

____References____

{354}
hide / / print
ref: Sabelli-1976.08 tags: anatomy of the spinal cord interneurons pyramidal tract commissure reflexes date: 04-23-2007 05:12 gmt revision:1 [0] [head]

Anatomy of the spinal cord

  • wow! detailed!!
  • the spinal cord is remarkably complex (of course, considering how old it is and how important it is for structuring movement and locomotion..well..most animals)
  • there is a lot of well-organized circuitry in the spinal cord mediating adaptive phenomena and reflexes like the clasp knife reflex (upper motoneuron disease where the resistance to flexion abruptly melts away when the joint is fully flexed)

____References____

{274}
hide / / print
ref: bookmark-0 tags: DARPA projects quantum electron spin date: 04-04-2007 20:39 gmt revision:0 [head]

http://www.darpa.mil/DSO/trans/transit.htm

{131}
hide / / print
ref: notes-0 tags: insular cortex anterior cingulate spindle neurons date: 0-0-2007 0:0 revision:0 [head]

spindle neurons are found in the insular cortex as well as the anterior cingulate cortex, but only, apparently, in great apes. Activity in the insular cortex has been found to be correlated to feeling empathy.