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: 99/4/1723    most recent 01143.2007v1 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 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 Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Hashimoto, K. Articles by Kita, H. Search for Related Content PubMed PubMed Citation Articles by Hashimoto, K. Articles by Kita, H.

Serotonin Activates Presynaptic and Postsynaptic Receptors in Rat Globus Pallidus

Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee, Memphis, Tennessee

Submitted 17 October 2007; accepted in final form 26 January 2008

Although recent histological, behavioral, and clinical studies suggest that serotonin (5-HT) plays significant roles in the control of pallidal activity, only little is known about the physiological action of 5-HT in the pallidum. Our recent unit recording study in monkeys suggested that 5-HT provides both presynaptic and postsynaptic modulations of pallidal neurons. The present study using rat brain slice preparations further explored these presynaptic and postsynaptic actions of 5-HT. Bath application of 5-HT or the 5-HT_1A/1B/1D/5/7 receptor (R) agonist 5-carboxamidotryptamine maleate (5-CT) depolarized some and hyperpolarized other pallidal neurons. Pretreatments of slices with blockers of the hyperpolarization–cyclic nucleotide-activated current or with the 5-HT_2/7R–selective antagonist mesulergine occluded 5-CT–induced depolarization. The 5-HT_1AR–selective blocker N-[2[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinylcyclohex- anecarboxamide maleate occluded the 5-CT–induced hyperpolarization. These results suggested involvement of 5-HT₇R and 5-HT_1AR in the postsynaptic depolarization and hyperpolarization, respectively. 5-CT presynaptically suppressed both internal capsule stimulation–induced excitatory postsynaptic currents (EPSCs) and striatal stimulation–induced inhibitory postsynaptic currents (IPSCs). The potencies of 5-CT on the presynaptic effects were 20- to 25-fold higher than on postsynaptic effects, suggesting that 5-HT mainly modulates presynaptic sites in the globus pallidus. Experiments with several antagonists suggested involvement of 5-HT_1B/DR in the presynaptic suppression of EPSCs. However, the receptor type involved in the presynaptic suppression of IPSCs was inconclusive. The present results provided evidence that 5-HT exerts significant control over the synaptic inputs and the autonomous activity of pallidal neurons.

This article has been cited by other articles:

				K. Watanabe, T. Kita, and H. Kita Presynaptic Actions of D2-Like Receptors in the Rat Cortico-Striato-Globus Pallidus Disynaptic Connection In Vitro J Neurophysiol, February 1, 2009; 101(2): 665 - 671. [Abstract] [Full Text] [PDF]

				C. Gunay, J. R. Edgerton, and D. Jaeger Channel Density Distributions Explain Spiking Variability in the Globus Pallidus: A Combined Physiology and Computer Simulation Database Approach J. Neurosci., July 23, 2008; 28(30): 7476 - 7491. [Abstract] [Full Text] [PDF]