Cholinergic suppression of visual responses in primate V1 is mediated by GABAergic inhibition

Anita A. Disney, Chiye Aoki, Michael J. Hawken

Research output: Contribution to journalArticle

Abstract

Acetylcholine (ACh) has been implicated in selective attention. To understand the local circuit action of ACh, we iontophoresed cholinergic agonists into the primate primary visual cortex (V1) while presenting optimal visual stimuli. Consistent with our previous anatomical studies showing that GABAergic neurons in V1 express ACh receptors to a greater extent than do excitatory neurons, we observed suppressed visual responses in 36% of recorded neurons outside V1's primary thalamorecipient layer (4c). This suppression is blocked by the GABAA receptor antagonist gabazine. Within layer 4c, ACh release produces a response gain enhancement (Disney AA, Aoki C, Hawken MJ. Neuron 56: 701-713, 2007); elsewhere, ACh suppresses response gain by strengthening inhibition. Our finding contrasts with the observation that the dominant mechanism of suppression in the neocortex of rats is reduced glutamate release. We propose that in primates, distinct cholinergic receptor subtypes are recruited on specific cell types and in specific lamina to yield opposing modulatory effects that together increase neurons' responsiveness to optimal stimuli without changing tuning width.

Original languageEnglish (US)
Pages (from-to)1907-1923
Number of pages17
JournalJournal of neurophysiology
Volume108
Issue number7
DOIs
StatePublished - Oct 1 2012

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Keywords

  • Muscarinic receptor
  • Neuromodulation
  • Visual cortex

ASJC Scopus subject areas

  • Neuroscience(all)
  • Physiology

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