Differential depression of inhibitory synaptic responses in feedforward and feedback circuits between different areas of mouse visual cortex

Hongwei Dong, Zhenwei Shao, Jeanne M. Nerbonne, Andreas Burkhalter

Research output: Contribution to journalArticle

29 Scopus citations

Abstract

Recordings of synaptic responses of pyramidal neurons to feedback (FB) inputs from higher to lower areas of visual cortex show that excitatory synaptic responses are only weakly opposed by disynaptic inhibition. Whether weak inhibition is preserved at high frequencies remains unknown. Whole-cell recordings were performed in pyramidal cells of mouse visual cortex to study the frequency dependence of excitatory and inhibitory postsynaptic currents (EPSCs, IPSCs) elicited by feedforward (FF) input from the primary visual cortex (V1) to the higher lateromedial area (LM) and by FB input from the LM to V1. EPSCs showed similar frequency dependencies in FF and FB pathways; the amplitudes decreased during stimulus trains, and the depression was larger at higher frequencies. IPSCs decreased during repetitive stimulation, and the depression increased at higher frequencies. At >20 Hz, the depression of IPSCs in the FB pathway was greater than in the FF pathway. Thus, unlike FF circuits, FB circuits provide balanced excitatory and inhibitory inputs across a wide range of frequencies. This property was shown to be critically important in cortical circuits that modulate the gain of pyramidal cell firing (Chance et al. [2002] Neuron 35:773-782).

Original languageEnglish
Pages (from-to)361-373
Number of pages13
JournalJournal of Comparative Neurology
Volume475
Issue number3
DOIs
StatePublished - Jul 26 2004

Keywords

  • Excitation
  • Inhibition
  • Intracortical connections
  • Short-term plasticity
  • Synaptic depression
  • Visual areas

Fingerprint Dive into the research topics of 'Differential depression of inhibitory synaptic responses in feedforward and feedback circuits between different areas of mouse visual cortex'. Together they form a unique fingerprint.

  • Cite this