Modifications of head turning and circling movement following sulpiride microinjections into nucleus accumbens in the rat.
The aim of this study was to determine whether a relationship exists between nucleus accumbens D2 receptors, circling behavior, and its first stage, the head turning. Rats were unilaterally lesioned in the substantia nigra with 6-hydroxydopamine and afterward treated with d-amphetamine IP following bilateral intraaccumbens microinjections (1, 5, 10 micrograms/0.5 microliters) of sulpiride, a D2 receptor antagonist. Computer-assisted video analysis allowed the study of some parameters (number of turns, type of turn, head turning duration, degree and speed) characterizing rotatory activity. Sulpiride microinfusion resulted in a dose-dependent decrease of the number of turns and head rotation speed and in a dose-dependent increase of head-turning duration. Two turn types were observed in relation to the animal's position: a large head-to-tail position with a short-diameter turn type following sulpiride microinjection, and a close head-to-tail position in relation to a wide diameter turn type in the control condition (saline). The results show a relationship between head turning parameters, circling behavior, and D2 receptors in nucleus accumbens, which may be also involved in the regulation of some mechanisms related to sensory-motor integration in the rat.
Emmi
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Institute of Human Physiology, University of Palermo, Italy.
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Amato
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D000818:Animals; D003913:Dextroamphetamine / Q000494:pharmacology; D015259:Dopamine Agents / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D065127:Dopamine D2 Receptor Antagonists; D004305:Dose-Response Relationship, Drug; D006257:Head; D008297:Male; D008845:Microinjections; D009714:Nucleus Accumbens / Q000502:physiology*; D016627:Oxidopamine; D051381:Rats; D017208:Rats, Wistar; D012399:Rotation; D013239:Stereotyped Behavior / Q000187:drug effects*; D013469:Sulpiride / Q000008:administration & dosage / Q000494:pharmacology*; D013563:Sympathectomy, Chemical
D015259:Dopamine Agents; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D013469:Sulpiride; D016627:Oxidopamine; D003913:Dextroamphetamine