Professor Stephen Williams

Queensland Brain Institute, University of Queensland

Title: "Cholinergic modulation is an essential component of neocortical circuit computations"


The ascending cholinergic system is known to regulate cognitive functions such as attention, perception and memory, but it remains unclear how this modulation is executed in neocortical circuits. Here we demonstrate that the cholinergic system dynamically controls active dendritic integration in neocortical principal neurons to allow behavioral state control over the fundamental computations produced by neocortical circuits. Direct dendritic recordings from layer 5B pyramidal neurons revealed that the synaptic release of acetylcholine selectively enhanced active dendritic processing and facilitated the associative integration of peri-somatic and dendritic excitatory input. Mechanistically, this action was mediated by the muscarinic acetylcholine receptor (mAChR)-dependent enhancement of dendritic calcium channel activity. In behaving animals, the antagonism of mAChRs attenuated dendritic calcium signals generated by associative integration during an active sensing task. The ascending cholinergic system therefore acts as a permissive modulator to engage a fundamental neocortical computation during active sensation. Thus, we have identified an important biophysical substrate that potentially mediates the capacity of the cholinergic system to regulate higher order brain function. 


About Neuroscience Seminars

Neuroscience seminars at the QBI play a major role in the advancement of neuroscience in the Asia-Pacific region. The primary goal of these seminars is to promote excellence in neuroscience through the exchange of ideas, establishing new collaborations and augmenting partnerships already in place.

Seminars in the QBI Auditorium on Level 7 are held on Wednesdays at 12-1pm, which are sometimes simulcast on Zoom (with approval from the speaker). We also occassionally hold seminars from international speakers via Zoom. The days and times of these seminars will vary depending on the time zone of the speaker. Please see each seminar listed below for details. 


Neuroscience Seminars archive 2005-2018