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: 92/4/1973    most recent 01036.2003v1 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 (6) Citing Articles via Google Scholar Google Scholar Articles by Nevet, A. Articles by Bergman, H. Search for Related Content PubMed PubMed Citation Articles by Nevet, A. Articles by Bergman, H.

TRANSLATIONAL PHYSIOLOGY

Discharge Rate of Substantia Nigra Pars Reticulata Neurons Is Reduced In Non-Parkinsonian Monkeys With Apomorphine-Induced Orofacial Dyskinesia

¹Department of Physiology, The Hebrew University-Hadassah Medical School, Jerusalem 91120; and ²Center for Neural Computation and ³Eric Roland Center for Neurodegenerative Diseases, The Hebrew University, Jerusalem 91904, Israel

Submitted 27 October 2003; accepted in final form 24 April 2004

Involuntary movements (dyskinesia) are a common symptom of dopamine-replacement therapy in parkinsonian patients, neuroleptic drug treatment of mental patients, and tic disorders. Levodopa-induced dyskinesia has been shown to be associated with substantial reduction of firing rate in the internal part of the globus pallidus. This study characterizes the changes that occur in the activity of the substantia nigra pars reticulata (SNr) of non-parkinsonian (normal) monkeys with apomorphine (APO)-induced orofacial dyskinesia. We conducted extracellular recordings of SNr neurons of two monkeys before and after induction of orofacial dyskinesia by systemic administration of APO. Involuntary orofacial movements appeared a few minutes after the injections and lasted 20–40 min. Almost all recorded neurons changed their firing rate after APO injection (96%), and most declined (70%). The mean amplitude of decreases was also larger than that of increases (40 vs. 21% of the control rate). Changes in firing pattern were not significant on average. Pairs of SNr neurons were uncorrelated before APO injection, similar to the normal pallidum. However, unlike the increased correlations in the pallidum that accompany parkinsonism, orofacilal dyskinesia in non-parkinsonian monkeys was not associated with changes in correlation between SNr neurons. We conclude that normal monkeys treated with APO can model orofacial dyskinesia and tic disorders that are a consequence of dopaminergic over-activity. These symptoms appear to be more related to reduced firing rate of SNr neurons and thus to disinhibition of their targets, than to changes in pattern and synchronization.

This article has been cited by other articles:

				N. Parush, D. Arkadir, A. Nevet, G. Morris, N. Tishby, I. Nelken, and H. Bergman Encoding by Response Duration in the Basal Ganglia J Neurophysiol, December 1, 2008; 100(6): 3244 - 3252. [Abstract] [Full Text] [PDF]

				F.-W. Zhou, S. G. Matta, and F.-M. Zhou Constitutively Active TRPC3 Channels Regulate Basal Ganglia Output Neurons J. Neurosci., January 9, 2008; 28(2): 473 - 482. [Abstract] [Full Text] [PDF]

				A. Nevet, G. Morris, G. Saban, D. Arkadir, and H. Bergman Lack of Spike-Count and Spike-Time Correlations in the Substantia Nigra Reticulata Despite Overlap of Neural Responses J Neurophysiol, October 1, 2007; 98(4): 2232 - 2243. [Abstract] [Full Text] [PDF]

				F.-W. Zhou, J.-J. Xu, Y. Zhao, M. S. LeDoux, and F.-M. Zhou Opposite Functions of Histamine H1 and H2 Receptors and H3 Receptor in Substantia Nigra Pars Reticulata J Neurophysiol, September 1, 2006; 96(3): 1581 - 1591. [Abstract] [Full Text] [PDF]