Release of acetylcholine in the ventral striatum is influenced by histamine receptors.
To investigate whether histamine receptor ligands influence the in vivo-release of acetylcholine in the ventral striatum, this brain region was superfused with histamine receptor agonists or antagonists through a push-pull cannula and drug effects on the release of acetylcholine were investigated. Histamine, the H1 receptor agonist 2-thiazolyl-ethylamine and the H3 receptor antagonist thioperamide enhanced acetylcholine release, while the H3 receptor agonist (R)-alpha-methylhistamine was ineffective. The results indicate that H1 receptors and H3 receptors modulate acetylcholine release. The thioperamide-induced increase of acetylcholine release might be exerted via H3-receptors located on cholinergic terminals. Alternatively, thioperamide might enhance acetylcholine release by increasing endogenous histamine release via H3 autoreceptors. It is concluded that, via stimulation of striatal H1- and H3 receptors, histaminergic neurons are involved in the regulation of cholinergic neuronal activity in the ventral striatum.
Department of Pharmacology and Toxicology, University of Innsbruck, Austria.
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D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D017442:Histamine Agonists / Q000494:pharmacology; D006633:Histamine Antagonists; D008297:Male; D008761:Methylhistamines / Q000494:pharmacology; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D011968:Receptors, Histamine / Q000187:drug effects / Q000502:physiology*
D017442:Histamine Agonists; D006633:Histamine Antagonists; D008761:Methylhistamines; D010880:Piperidines; D011968:Receptors, Histamine; C069357:alpha-methylhistamine; C052075:thioperamide; D000109:Acetylcholine