HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 564/1/83    most recent jphysiol.2004.080622v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Garner, H. L Articles by Henderson, Z. Search for Related Content PubMed PubMed Citation Articles by Garner, H. L Articles by Henderson, Z.

¹ School of Biomedical Sciences, The Worsley Building, University of Leeds, Leeds LS2 9JT, UK

The medial septum–diagonal band (MSDB) complex, via the septohippocampal pathway, is thought to be critical for the generation and/or maintenance of the hippocampal theta rhythm in vivo. The aim was to determine whether the MSDB is capable of generating and maintaining its own rhythmic firing activity, a mechanism by which it could impose a theta frequency oscillatory activity on the hippocampus. Bath application of 50–300 nM kainate to an in vitro preparation of 20- to 25-day-old rat MSDB elicited rhythmic extracellular field activity primarily within the theta frequency band (4–12 Hz). This activity was observed both at 33°C and at 37°C, and was localized to the midline part of the MSDB that is rich in parvalbumin-containing neurones. The application of neurotransmitter receptor antagonists and putative gap junction blockers showed that the oscillatory field activity was dependent upon the activation of GABA_A receptors and possibly gap junctions, but not on the activation of NMDA, GABA_B, muscarinic or nicotinic receptors. The frequency of the oscillatory activity was reduced by the application of diazepam or low doses of baclofen. Intracellular recording showed that concomitant action potential firing activity in putative GABAergic and cholinergic neurone populations was of a single spiking rather than a bursting firing nature, and was coherent with extracellularly recorded oscillatory field activity. We conclude that kainate activation of neuronal circuitry in the MSDB is capable of synchronization of rhythmic activity in the MSDB, and that this may underlie the mechanism for phase-locking rhythmic burst activity in the MSDB in vivo.

(Received 6 December 2004; accepted after revision 24 January 2005; first published online 27 January 2005)
Corresponding author Z. Henderson: School of Biomedical Sciences, The Worsley Building, University of Leeds, Leeds LS2 9JT, UK. Email: z.henderson{at}leeds.ac.uk

This article has been cited by other articles:

				G. Gonzalez-Burgos and D. A. Lewis GABA Neurons and the Mechanisms of Network Oscillations: Implications for Understanding Cortical Dysfunction in Schizophrenia Schizophr Bull, September 1, 2008; 34(5): 944 - 961. [Abstract] [Full Text] [PDF]

				J. R. Huxter, L. E. Zinyuk, E. v. L. Roloff, V. R. J. Clarke, N. P. Dolman, J. C. A. More, D. E. Jane, G. L. Collingridge, and R. U. Muller Inhibition of Kainate Receptors Reduces the Frequency of Hippocampal Theta Oscillations J. Neurosci., February 28, 2007; 27(9): 2212 - 2223. [Abstract] [Full Text] [PDF]

				F Manseau, M Danik, and S Williams A functional glutamatergic neurone network in the medial septum and diagonal band area J. Physiol., August 1, 2005; 566(3): 865 - 884. [Abstract] [Full Text] [PDF]