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) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science 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 ISI Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Anderson, M. I. Articles by O'Mara, S. M. Search for Related Content PubMed PubMed Citation Articles by Anderson, M. I. Articles by O'Mara, S. M.

Analysis of Recordings of Single-Unit Firing and Population Activity in the Dorsal Subiculum of Unrestrained, Freely Moving Rats

Department of Psychology and Trinity College Institute of Neuroscience, University of Dublin, Trinity College, Dublin 2, Ireland

Submitted 22 August 2002; accepted in final form 3 March 2003

We examined neuronal activity in the dorsal subiculum of unrestrained, male adult Wistar rats, which were implanted with a moveable eight-electrode microdrive. The subiculum is the primary hippocampal formation output area and is comparatively uninvestigated neurophysiologically. We compared subicular unit activity and the subicular EEG while rats occupied a small, restricted environment and also correlated neuronal activity with the ongoing behavior of the animal. Units were separated using their electrophysiological characteristics into bursting units, regular spiking units, theta-modulated units, and fast spiking units. The bursting and regular spiking unit classes are similar to hippocampal CA1 units, whereas the fast spiking units appear to be interneurons. Bursting units were variable in their behavior: some units bursted regularly, and others bursted only occasionally. Theta-modulated units have not been described before; these were similar to regular spiking units in all respects except that they increased their firing significantly when theta oscillations were present in the simultaneous EEG record. Subicular EEG was similar to hippocampal EEG, with theta oscillations dominating "alert, moving" behaviors, while large amplitude irregular activity (LIA), which included sharp waves, predominated when theta oscillations were not present, mainly during "alert, still" and "quiet" behaviors. A relatively small proportion of subicular recordings (approximately 32%) were phase-locked to theta; this is a smaller proportion than in areas from which the subiculum takes major inputs. The relative lack of entrainment of subicular neurons by this important intrinsic rhythm is suggestive of a limit to which theta might be capable of affecting both subicular and hippocampal information processing more generally.

This article has been cited by other articles:

				W. B. Wilent and D. A. Nitz Discrete Place Fields of Hippocampal Formation Interneurons J Neurophysiol, June 1, 2007; 97(6): 4152 - 4161. [Abstract] [Full Text] [PDF]

				C. P. Wu, H. L. Huang, M. N. Asl, J. W. He, J. Gillis, F. K. Skinner, and L. Zhang Spontaneous rhythmic field potentials of isolated mouse hippocampal-subicular-entorhinal cortices in vitro J. Physiol., October 15, 2006; 576(2): 457 - 476. [Abstract] [Full Text] [PDF]