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[0] Buonomano DV, Merzenich MM, Cortical plasticity: from synapses to maps.Annu Rev Neurosci 21no Issue 149-86 (1998)

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ref: -2012 tags: octopamine STDP locust LTP LTD olfactory bulb date: 03-11-2019 18:59 gmt revision:5 [4] [3] [2] [1] [0] [head]

PMID-22278062 Conditional modulation of spike-timing-dependent plasticity for olfactory learning.

  • Looked at the synapes from the Muschroom body (Kenyon cells, sparse code) to the beta-lobe (bLN) in locusts.
  • Used in-vivo dendrite patch, sharp micropipette.
  • Found that, with a controlled mushroom body extracellular stim for plasticity induction protocol at the KC-> bLN synapese, were able to get potentiation and depression in accord with STDP.
  • This STDP became pure depression in the presence of octopamine
  • See also / supercedes: Synaptic Learning Rules and Sparse Coding in a Model Sensory System Luca A. Finelli ,Seth Haney, Maxim Bazhenov, Mark Stopfer, Terrence J. Sejnowski 2008

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ref: -0 tags: recurrent cortical model adaptation gain V1 LTD date: 03-27-2018 17:48 gmt revision:1 [0] [head]

PMID-18336081 Adaptive integration in the visual cortex by depressing recurrent cortical circuits.

  • Mainly focused on the experimental observation that decreasing contrast increases latency to both behavioral and neural response (latter in the later visual areas..)
  • Idea is that synaptic depression in recurrent cortical connections mediates this 'adaptive integration' time-constant to maintain reliability.
  • Model also explains persistent activity after a flashed stimulus.
  • No plasticity or learning, though.
  • Rather elegant and well explained.

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ref: Buonomano-1998.01 tags: cortical plasticity learning review LTD LTP date: 10-07-2008 03:27 gmt revision:1 [0] [head]

PMID-9530495[0] Cortical plasticity: from synapses to maps

  • focuses on synaptic plasticity as the underlying mechanism of behavior-dependent cortical maps/representations.
  • "within limits, the cortex can allocate cortical area in a use-dependent manner"
  • synaptic plasticity -> STDP via NMDA, etc.
    • demonstrated with intracellular recordings of cat M1 & simultaneous stimulation of the ventrolateral thalamus & intracellular depolarization. Facilitation was short lasting and not present in all neurons.
    • demonstrated in rat auditory cortex / recording in layer 2/3 , stimulate layer 2/3 & White matter/6.
    • review of Ca+ hypothesis of LTP/LTD balance: if the Ca+ influc is below a threshold, LTD occurs; if it is above a certain threshold, LTP.
      • not sure how long LTD has been demonstrated -- 15 min?
  • cellular conditioning = direct induction of plastic changes in the selective responses of individual neurons in vivo as a result of short-term conditioning protocols. this is what we are interested in, for now.
    • this review does not explicitly deal with BG-DA / ACh reinforcement, only timing dependent plasticity, in visual and auditory cortex.
  • cortical plasticity:
    • talk about the revealing/unmasking of hidden responses when sections of cortex are deafferented or digits were amputated.
    • talk about training-based approaches: training increases cortical representation of a sensory modality / skill/ etc. The cortex can differentially 'allocate' area in a use-dependent manner throughout life.
    • cortical map changes are not reflected by changes in thalamic somatotopy.

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