Brain and Mind Institute Seminar

07-01-09 Wednesday, 12h15, AI1153

Robert Froemke
Center for Integrative Neuroscience University of California, San Francisco
http://keck.ucsf.edu/keck/

A synaptic memory trace for cortical receptive field plasticity

Abstract:

In conclusion, heterogeneous networks are capable of performing tasks involving hundreds of events that appear in different contexts, indicating that mixed selectivity may be a general principle underlying important high cognitive functions. Neural networks of the cerebral cortex continually change throughout life, allowing us to learn from our sensations of the world. While the developing cortex is readily altered by sensory experience, older brains are less plastic. Adult cortical plasticity seems to require more widespread coordination across diverse brain regions, including the activation of subcortical neuromodulator systems, reflecting the importance of behavioural significance and context for learning. Here I will present the results of recent experiments on the synaptic basis of receptive field plasticity in adult primary auditory cortex. I will describe the changes both to spike output and to synaptic input after sensory stimuli were paired with electrical stimulation of the nucleus basalis- a key center for attention, arousal, and learning. I will then discuss the network elements and temporal dynamics of excitatory and inhibitory synaptic plasticity in vivo, their possible relation to spike-timing-dependent plasticity, and newer results on synaptic receptive field plasticity in young animals.

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