1. Coleman Memorial Laboratory and W. M. Keck Foundation Center for Integrative Neuroscience, Department of Otolaryngology, University of California, San Francisco, California 94143, USA

Correspondence to: Robert C. Froemke¹ Correspondence and requests for materials should be addressed to R.C.F. (Email: rfroemke@phy.ucsf.edu).

Abstract

Receptive fields of sensory cortical neurons are plastic, changing in response to alterations of neural activity or sensory experience^{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}. In this way, cortical representations of the sensory environment can incorporate new information about the world, depending on the relevance or value of particular stimuli^{1, 6, 9}. Neuromodulation is required for cortical plasticity, but it is uncertain how subcortical neuromodulatory systems, such as the cholinergic nucleus basalis, interact with and refine cortical circuits^{13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24}. Here we determine the dynamics of synaptic receptive field plasticity in the adult primary auditory cortex (also known as AI) using in vivo whole-cell recording. Pairing sensory stimulation with nucleus basalis activation shifted the preferred stimuli of cortical neurons by inducing a rapid reduction of synaptic inhibition within seconds, which was followed by a large increase in excitation, both specific to the paired stimulus. Although nucleus basalis was stimulated only for a few minutes, reorganization of synaptic tuning curves progressed for hours thereafter: inhibition slowly increased in an activity-dependent manner to rebalance the persistent enhancement of excitation, leading to a retuned receptive field with new preference for the paired stimulus. This restricted period of disinhibition may be a fundamental mechanism for receptive field plasticity, and could serve as a memory trace^{9, 25} for stimuli or episodes that have acquired new behavioural significance.

MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.