Abstract
The role of histamine and its receptors in basal ganglia neurocircuitry was assessed in apomorphine-induced turning behavior. Rats with unilateral 6-hydroxydopamine lesions of the substantia nigra pars compacta and medial forebrain bundle were administered histaminergic agents, and apomorphine-induced turning behavior was tested on Days 7 and 14 post-lesion. Compared with saline-treated rats, histidine (500 mg/kg, i.p.), a precursor of histamine, increased turning behavior (p<0.05), while alpha-fluoromethylhistidine (alpha-FMH, 25 microg, i.c.v.), an irreversible inhibitor of histidine decarboxylase, decreased turning behavior (p<0.05) but only on Day 14 post-lesion. Both the histamine H(1) receptor antagonist pyrilamine (10 and 50 microg, i.c.v.) and the H(2) receptor antagonist cimetidine (10 and 50 microg, i.c.v.) significantly decreased turning behavior on Days 7 and 14 post-lesion. The histamine H(3) receptor agonist immepip (10 microg, i.c.v.) decreased turning behavior (p<0.05) on Day 14 post-lesion. The present findings indicate the complex interactions of histamine on basal ganglia function.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Apomorphine / pharmacology*
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Basal Ganglia / drug effects
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Enzyme Inhibitors / administration & dosage
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Enzyme Inhibitors / pharmacology
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Histamine Agonists / pharmacology*
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Histamine H1 Antagonists / pharmacology*
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Histamine H2 Antagonists / pharmacology*
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Histidine / pharmacology
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Histidine Decarboxylase / antagonists & inhibitors
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Histidine Decarboxylase / metabolism*
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Imidazoles / pharmacology
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Injections, Intraventricular
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Male
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Methylhistidines / administration & dosage
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Methylhistidines / pharmacology
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Narcotic Antagonists / pharmacology*
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Oxidopamine / toxicity*
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Piperidines / pharmacology
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Pyrilamine / pharmacology
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Rats
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Rats, Sprague-Dawley
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Stereotyped Behavior / drug effects*
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Sympatholytics / toxicity*
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Synapses / drug effects
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Thiourea / analogs & derivatives
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Thiourea / pharmacology
Substances
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Enzyme Inhibitors
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Histamine Agonists
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Histamine H1 Antagonists
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Histamine H2 Antagonists
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Imidazoles
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Methylhistidines
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Narcotic Antagonists
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Piperidines
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Sympatholytics
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4-(1H-imidazol-4-ylmethyl)piperidine
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Histidine
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alpha-fluoromethylhistidine
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Oxidopamine
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Histidine Decarboxylase
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Thiourea
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Pyrilamine
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Apomorphine
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clobenpropit