Skirball Institute and NYU Neuroscience Institute
NYU School of Medicine
November 6, 2012
Long-term cortical synaptic plasticity improves sensory perception
Synapses and receptive fields of the cerebral cortex are plastic. However, changes to specific inputs must be coordinated within neural networks to ensure that excitability and feature selectivity are appropriately configured for perception of the sensory environment. Here I will discuss previous and unpublished results showing how long-lasting positive and negative changes to auditory cortical synapses in adult rats were induced by pairing sounds with activation of the cholinergic neuromodulatory system. Synaptic modifications were precisely orchestrated across entire receptive fields, conserving mean excitation while reducing overall variance, and parameters of cortical synaptic receptive fields (frequency and intensity) could be modified independently. Computational analysis indicated that decreased variability should increase detection and discrimination of near-threshold or previously imperceptible stimuli, and we confirmed this psychophysically in behaving animals. I will also describe newer results comparing the effects of acetylcholine to the other main attention-related modulator, noradrenalin. Our work indicates that direct modification of specific cortical inputs leads to wide-scale synaptic changes, which collectively support improved auditory perception and enhanced behavioral performance.