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) 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 Avignone, E. Articles by Cherubini, E. Search for Related Content PubMed PubMed Citation Articles by Avignone, E. Articles by Cherubini, E.

Muscarinic receptor modulation of GABA-mediated giant depolarizing potentials in the neonatal rat hippocampus

Elena Avignone and Enrico Cherubini

The whole-cell patch clamp technique was used to study the role of muscarinic receptors in regulating the frequency of giant depolarizing potentials (GDPs) in CA3 hippocampal neurones in slices from postnatal (P) P1-P8 rats.

Atropine (1 µM) reduced the frequency of GDPs by 64·2 ± 2·9 %. The acetylcholinesterase inhibitor edrophonium (20 µM) increased the frequency of GDPs in a developmentally regulated way. This effect was antagonized by the M1 muscarinic receptor antagonist pirenzepine.

In the presence of edrophonium, tetanic stimulation of cholinergic fibres induced either an enhancement of GDP frequency (179 ± 79 %) or a membrane depolarization (27 ± 16 mV) associated with an increase in synaptic noise. These effects were prevented by atropine.

Application of carbachol (3 µM) produced an increase in GDP frequency that at P5-P6 was associated with a membrane depolarization and an increase in synaptic noise. These effects were prevented by atropine, pirenzepine (3 µM) and bicuculline (10 µM).

In the presence of pirenzepine, carbachol reduced GDP frequency by 50 ± 4 %. Conversely, in the presence of methoctramine (3 µM), carbachol enhanced GDP frequency by 117 ± 4 %.

It is concluded that endogenous acetylcholine, through the activation of M1 receptors, enhances the release of -aminobutyric acid (GABA), in a developmentally regulated way. On the other hand, carbachol exerts both an up- and downregulation of GABA release through the activation of M1 and M2 receptors, respectively.

This article has been cited by other articles:

				I. L. Hanganu, J. F. Staiger, Y. Ben-Ari, and R. Khazipov Cholinergic Modulation of Spindle Bursts in the Neonatal Rat Visual Cortex In Vivo J. Neurosci., May 23, 2007; 27(21): 5694 - 5705. [Abstract] [Full Text] [PDF]

				V. F. Safiulina, A. M. Kasyanov, R. Giniatullin, and E. Cherubini Adenosine Down-Regulates Giant Depolarizing Potentials in the Developing Rat Hippocampus by Exerting a Negative Control on Glutamatergic Inputs J Neurophysiol, October 1, 2005; 94(4): 2797 - 2804. [Abstract] [Full Text] [PDF]

				V. F Safiulina, A. M Kasyanov, E. Sokolova, E. Cherubini, and R. Giniatullin ATP contributes to the generation of network-driven giant depolarizing potentials in the neonatal rat hippocampus J. Physiol., June 15, 2005; 565(3): 981 - 992. [Abstract] [Full Text] [PDF]

				W. Kilb and H. J. Luhmann Carbachol-induced Network Oscillations in the Intact Cerebral Cortex of the Newborn Rat Cereb Cortex, April 1, 2003; 13(4): 409 - 421. [Abstract] [Full Text] [PDF]

				L. Maggi, C. Le Magueresse, J.-P. Changeux, and E. Cherubini Nicotine activates immature "silent" connections in the developing hippocampus PNAS, February 18, 2003; 100(4): 2059 - 2064. [Abstract] [Full Text] [PDF]

				Y. Momose-Sato, N. Miyakawa, H. Mochida, S. Sasaki, and K. Sato Optical Analysis of Depolarization Waves in the Embryonic Brain: A Dual Network of Gap Junctions and Chemical Synapses J Neurophysiol, January 1, 2003; 89(1): 600 - 614. [Abstract] [Full Text] [PDF]

				A. Peinado Traveling Slow Waves of Neural Activity: A Novel Form of Network Activity in Developing Neocortex J. Neurosci., January 15, 2000; 20(2): RC54 - RC54. [Abstract] [Full Text] [PDF]