Model for (a)synchronous/spontaneous release, applied to CCK-positive Interneuron synapses

Abstract

Asynchronous and spontaneous neurotransmitter release remain elusive and constitute topics of considerable research both from the experimental and modeling perspective. This study proposes a parsimonious model that accounts for all modes of vesicle exocytosis and Short-Term Synaptic Plasticity (STSP). The modeling novelty is based on principles of slow-fast dynamical systems theory. The model's validity is shown by its good agreement with experimental data obtained from in vitro electrophysiological dual whole-cell recordings between local cholecystokinin (CKK)-positive, Schaffer collateral associated (SCA) interneurons in the CA1 region of rat hippocampus~\cite{AfiaAli2007,AfiaAli2010}. These unitary synapses display asynchronous release, governed by the retrograde release of endocannabinoid in response to post-synaptic membrane depolarisation. This work will advance our understanding of the physiology underlying differential exocytosis, and facilitate large-scale neuronal simulations.