JN Email Content Delivery
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Neurophysiol 79: 1633-1642, 1998;
0022-3077/98 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Apartis, E.
Right arrow Articles by Bassant, M. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Apartis, E.
Right arrow Articles by Bassant, M. H.

The Journal of Neurophysiology Vol. 79 No. 4 April 1998, pp. 1633-1642
Copyright ©1998 The American Physiological Society

Loss of Rhythmically Bursting Neurons in Rat Medial Septum Following Selective Lesion of Septohippocampal Cholinergic System

Emmanuelle Apartis1, 2, Frederique R. Poindessous-Jazat1, Yvon A. Lamour1, 2, , and Marie H. Bassant1

1 Unité de Recherches de Physiopharmacologie du Système Nerveux, Institut National de la Santé et de la Recherche Médicale U 161, 75014 Paris; and 2 Service d'Explorations Fonctionnelles du Système Nerveux, Hopital Lariboisière, 75010 Paris, France

Apartis, Emmanuelle, Frederique R. Poindessous-Jazat, Yvon A. Lamour, and Marie H. Bassant. Loss of rhythmically bursting neurons in rat medial septum following selective lesion of septohippocampal cholinergic system. J. Neurophysiol. 79: 1633-1642, 1998. The medial septum contains cholinergic and GABAergic neurons that project to the hippocampal formation. A significant proportion of the septohippocampal neurons (SHN) exhibit a rhythmically bursting (RB) activity that is involved in the generation of the hippocampal theta rhythm. The neurochemical nature of septal RB neurons is not firmly established. To address this question, the septal unit activity has been recorded in rats after selective destruction of the cholinergic septal neurons by the immunotoxin 192 IgG-saporin. Experiments have been performed in urethan-anesthetized and unanesthetized rats, 14-21 days after lesion. Acetylcholinesterase (AChE) histochemistry revealed a near-complete loss of cholinergic septal neurons and of cholinergic fibers in the hippocampus. The recorded neurons were located in the medial septum-diagonal band of Broca area. A number of these neurons were identified as projecting to the hippocampus (SHN) by their antidromic response to the electrical stimulation of the fimbria-fornix. In urethan-anesthetized lesioned rats, the percentage of RB neurons decreased significantly as compared with controls (17 vs. 41% for SHNs and 5 vs. 19% for unidentified septal neurons). The axonal conduction velocity and the burst frequency of the SHNs that retained a RB activity were higher in lesioned as compared with control rats. The number of spikes per burst was lower and the burst duration was shorter in lesioned rats as compared with controls. The urethan-resistant hippocampal theta was altered both in terms of frequency and amplitude. In unanesthetized lesioned rats, no RB septal neurons were found during arousal, as compared with 25% in controls. Their number was also markedly reduced during paradoxical sleep (9.7 vs. 38.5%). Histochemistry in 192 IgG-saporin-treated rats showed that RB neurons were found in areas devoid of AChE-positive neurons but containing parvalbumine-positive (presumably GABAergic) neurons. These data show that RB activity is considerably reduced after selective lesion of the cholinergic medial septal neurons. They suggested that the large majority of the RB septal neurons are cholinergic and that the few neurons that display RB activity in lesioned rats are GABAergic.




This article has been cited by other articles:


Home page
 J. Neurosci.Home page
A. Pascale Simon, F. Poindessous-Jazat, P. Dutar, J. Epelbaum, and M.-H. Bassant
Firing properties of anatomically identified neurons in the medial septum of anesthetized and unanesthetized restrained rats.
J. Neurosci., August 30, 2006; 26(35): 9038 - 9046.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
T. E. Fitch, R. N. Sahr, B. J. Eastwood, F. C. Zhou, and C. R. Yang
Dopamine D1/5 Receptor Modulation of Firing Rate and Bidirectional Theta Burst Firing in Medial Septal/Vertical Limb of Diagonal Band Neurons In Vivo
J Neurophysiol, May 1, 2006; 95(5): 2808 - 2820.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
M.-H. Bassant, A. Simon, F. Poindessous-Jazat, Z. Csaba, J. Epelbaum, and P. Dournaud
Medial Septal GABAergic Neurons Express the Somatostatin sst2A Receptor: Functional Consequences on Unit Firing and Hippocampal Theta
J. Neurosci., February 23, 2005; 25(8): 2032 - 2041.
[Abstract] [Full Text] [PDF]

Home page
 J. Neuropsychiatry Clin. Neurosi.Home page
K. N. Loganovsky and K. L. Yuryev
EEG Patterns in Persons Exposed to Ionizing Radiation as a Result of the Chernobyl Accident. Part 2: Quantitative EEG Analysis in Patients Who Had Acute Radiation Sickness
J Neuropsychiatry Clin Neurosci, February 1, 2004; 16(1): 70 - 82.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
X.-J. Wang
Pacemaker Neurons for the Theta Rhythm and Their Synchronization in the Septohippocampal Reciprocal Loop
J Neurophysiol, February 1, 2002; 87(2): 889 - 900.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
M. Wu, M. Shanabrough, C. Leranth, and M. Alreja
Cholinergic Excitation of Septohippocampal GABA But Not Cholinergic Neurons: Implications for Learning and Memory
J. Neurosci., May 15, 2000; 20(10): 3900 - 3908.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online