JPET xPharm- The Comprehensive Pharmacology Reference

Home Help [Feedback] [For Subscribers] [Archive] [Search] --
QUICK SEARCH:   [advanced]


     

Journal of Pharmacology And Experimental Therapeutics Fast Forward
First published on October 7, 2005; DOI: 10.1124/jpet.105.092718

This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
jpet.105.092718v1
316/2/608    most recent
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
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
Right arrow Author home page(s):
Bela Szabo
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Engler, B.
Right arrow Articles by Szabo, B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Engler, B.
Right arrow Articles by Szabo, B.


Received for publication July 18, 2005.
Revised September 18, 2005.
Accepted for publication October 6, 2005.

Effects of exogenous and endogenous cannabinoids on GABAergic neurotransmission between the caudate-putamen and the globus pallidus in the mouse

Birgit Engler 1, Ilka Freiman 1, Michal Urbanski 1, Bela Szabo 1*

1 Dept. of Pharmacology, University of Freiburg

* Address correspondence to: E-mail: szabo{at}pharmakol.uni-freiburg.de

Abstract

Globus pallidus neurons receive GABAergic input from the caudate-putamen via the striato-pallidal pathway. Anatomical studies indicate that many CB1 cannabinoid receptors are localised on terminals of striato-pallidal axons. Accordingly, the hypothesis of the present work was that activation of CB1 receptors presynaptically inhibits neurotransmission between striato-pallidal axons and globus pallidus neurons. In sagittal mouse brain slices, striato-pallidal axons were electrically stimulated in the caudate-putamen and the resulting GABAergic inhibitory post-synaptic currents (IPSCs) were recorded in globus pallidus neurons. The synthetic cannabinoid receptor agonists WIN55212-2 and CP55940 decreased the amplitude of IPSCs. The CB1 receptor antagonist rimonabant prevented the inhibition by WIN55212-2, pointing to involvement of CB1 receptors. Depolarisation of globus pallidus neurons induced a weak and short-lasting suppression of IPSCs (i.e., depolarisation-induced suppression of inhibition, DSI, occurred). Prevention of DSI by rimonabant indicates that endocannabinoids released from the postsynaptic neurons acted on CB1 receptors to suppress synaptic transmission. WIN55212-2 did not modify currents in globus pallidus neurons elicited by GABA released from its chemically bound ("caged") form by a flash pulse, suggesting that WIN55212-2 depressed neurotransmission presynaptically. For studying the mechanism of the inhibition of GABA release, terminals of striato-pallidal axons were labelled with a calcium-sensitive fluorescent dye. WIN55212-2 depressed the action potential-evoked increase in axon terminal calcium concentration. The results show that activation of CB1 receptors by exogenous and endogenous cannabinoids leads to presynaptic inhibition of neurotransmission between striato-pallidal axons and globus pallidus neurons. Depression of the action potential-evoked calcium influx into axon terminals is the probable mechanism of this inhibition.


Key words: basal ganglia, cannabinoid, electrophysiology, endocannabinoids, presynaptic receptor, synaptic transmission


This article has been cited by other articles:


Home page
 NeurologyHome page
E. Benarroch
Endocannabinoids in basal ganglia circuits: Implications for Parkinson disease
Neurology, July 17, 2007; 69(3): 306 - 309.
[Full Text] [PDF]

Home page
 J. Pharmacol. Exp. Ther.Home page
E. Sanchez-Pastor, X. Trujillo, M. Huerta, and F. Andrade
Effects of Cannabinoids on Synaptic Transmission in the Frog Neuromuscular Junction
J. Pharmacol. Exp. Ther., May 1, 2007; 321(2): 439 - 445.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
A. Hernandez, O. Ibanez-Sandoval, A. Sierra, R. Valdiosera, D. Tapia, V. Anaya, E. Galarraga, J. Bargas, and J. Aceves
Control of the Subthalamic Innervation of the Rat Globus Pallidus by D2/3 and D4 Dopamine Receptors
J Neurophysiol, December 1, 2006; 96(6): 2877 - 2888.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
B. Szabo, M. J. Urbanski, T. Bisogno, V. D. Marzo, A. Mendiguren, W. U. Baer, and I. Freiman
Depolarization-induced retrograde synaptic inhibition in the mouse cerebellar cortex is mediated by 2-arachidonoylglycerol
J. Physiol., November 15, 2006; 577(1): 263 - 280.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
M. E. Hofmann, B. Nahir, and C. J. Frazier
Endocannabinoid-Mediated Depolarization-Induced Suppression of Inhibition in Hilar Mossy Cells of the Rat Dentate Gyrus
J Neurophysiol, November 1, 2006; 96(5): 2501 - 2512.
[Abstract] [Full Text] [PDF]


Home Help [Feedback] [For Subscribers] [Archive] [Search] --
All ASPET Journals Molecular Pharmacology Pharmacological Reviews
Molecular Interventions Drug Metabolism and Disposition

Copyright © 2005 by the American Society for Pharmacology and Experimental Therapeutics.