Date: Tue, April 10, 15:00-17:00
Place: Room Dw601, D Block, IIS, The University of Tokyo

Invited Speaker: Dr. Allan Gulledge (Dartmouth Medical School)

Title: A new role for acetylcholine in cortical circuits

Abstract:  
Acetylcholine (ACh) plays a critical role in cognition, and decreased
cholinergic input to the cortex contributes to the memory deficits
observed in Alzheimer's Disease and other forms of dementia.  Yet the
mechanisms by which ACh modulates the activity of cortical neurons are
not fully understood. We have found that transient activation of
muscarinic-type ACh receptors produces a powerful inhibitory response in
cortical neurons that provide the bulk of extra-cortical afferent
projections, including layer 5 neurons in the neocortex, and CA1 neurons
in the hippocampus. Cortical neurons primarily participating in
intracortical signaling, including layer 2/3 pyramidal neurons in the
neocortex and CA3 neurons in the hippocampus, were not inhibited by
ACh. These data, which contrast with the traditional view of ACh being a
purely excitatory transmitter, suggest that transient ACh release in the
cortex will suppress cortical output while facilitating intracortical
processing.