Breadcrumb

 
 

Cholinergic modulation of the superficial layers of the parasubiculum.

Title:

Cholinergic modulation of the superficial layers of the parasubiculum.

Glasgow, Stephen (2011) Cholinergic modulation of the superficial layers of the parasubiculum. PhD thesis, Concordia University.

[img]
Preview
PDF - Accepted Version
5Mb

Abstract

ABSTRACT

Cholinergic modulation of the superficial layers of the parasubiculum

Stephen D. Glasgow, Ph.D.
Concordia University, 2011

Recent evidence suggests that the parahippocampal area, including the entorhinal cortex and parasubiculum, may play a crucial role in spatial processing and memory formation. However, little is known about the basic cellular and network properties of the parasubiculum, an isocortical brain region that receives input from the hippocampus and other subcortical regions associated with spatial navigation, and projects exclusively to the superficial layers of the entorhinal cortex. Neurons in layer II of the parasubiculum demonstrate theta-frequency membrane potential oscillations at near-threshold voltages that are generated via an interplay between a persistent Na+ current and the hyperpolarization-activated cationic current Ih, and these rhythmic fluctuations in membrane potential may contribute to the generation of oscillatory local field potentials. Further, the parasubiculum receives strong cholinergic projections from the medial septum. Acetylcholine has been linked to theta-frequency oscillations via regulation of cellular and network dynamics through membrane depolarization, while concurrently suppressing excitatory synaptic transmission, and it is likely that cholinergic receptor activation has similar effects in the parasubiculum. I found that activation of cholinergic receptors depolarizes layer II cells of the parasubiculum by exerting numerous effects on K+ channels, including IM and IKir, however also suppresses incoming excitatory synaptic transmission from the CA1. These results indicate that increases in cholinergic tone during network-level theta-frequency oscillations in the parasubiculum may increase neuronal excitability by exerting strong effects on postsynaptic conductances, but may also regulate network dynamics by reducing the strength of incoming afferents.

Divisions:Concordia University > Faculty of Arts and Science > Psychology
Item Type:Thesis (PhD)
Authors:Glasgow, Stephen
Institution:Concordia University
Degree Name:Ph. D.
Program:Psychology
Date:05 May 2011
Thesis Supervisor(s):Chapman, C. Andrew
Keywords:theta, hippocampus, entorhinal, electrophysiology, neuromodulation
ID Code:7503
Deposited By:STEPHEN DOUGLAS GLASGOW
Deposited On:13 Jun 2011 11:05
Last Modified:13 Jun 2011 11:05
All items in Spectrum are protected by copyright, with all rights reserved. The use of items is governed by Spectrum's terms of access.

Repository Staff Only: item control page

Document Downloads

More statistics for this item...

Concordia University - Footer