The Role of Cannabinoids in the Neurobiology of Sensory Gating: A firing rate model study

Zachariou, Margarita and Dissanayake, Dilshani and Owen, Markus and Mason, Rob and Coombes, Stephen (2006) The Role of Cannabinoids in the Neurobiology of Sensory Gating: A firing rate model study.

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Abstract

Gating of sensory (e.g. auditory) information has been demonstrated as a reduction in the auditory-evoked potential responses recorded in the brain of both normal animals and human subjects. Auditory gating is perturbed in schizophrenic patients and pharmacologically by drugs such as amphetamine, phencyclidine or ketamine, which precipitate schizophrenic-like symptoms in normal subjects. The neurobiological basis underlying this sensory gating can be investigated using local field potential recordings from single electrodes. In this paper we use such technology to investigate the role of cannabinoids in sensory gating. Cannabinoids represent a fundamentally new class of retrograde messengers which are released postsynaptically and bind to presynaptic receptors. In this way they allow fine-tuning of neuronal response, and in particular can lead to so-called depolarization-induced suppression of inhibition (DSI). Our experimental results show that application of the exogenous cannabinoid WIN55, 212-2 can abolish sensory gating as measured by the amplitude of local field responses in rat hippocampal region CA3. Importantly we develop a simple firing rate population model of CA3 and show that gating is heavily dependent upon the presence of a slow inhibitory (GABAB) pathway. Moreover, a simple phenomenological model of cannabinoid dynamics underlying DSI is shown to abolish gating in a manner consistent with our experimental findings.

Item Type:Article
Uncontrolled Keywords:Sensory gating, cannabinoids, depolarization-induced suppression of inhibition, firing rate models
Schools/Departments:Faculty of Science > School of Mathematical Sciences
Faculty of Medicine and Health Sciences > School of Biomedical Sciences
ID Code:421
Deposited By:Coombes, Prof Stephen
Deposited On:06 Oct 2006
Last Modified:27 Jun 2011 11:13

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