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Dopaminergic neurons of the substantia nigra pars compacta are excited by nicotine and acetylcholine, and possess both high-affinity nicotine binding sites and intense acetylcholinesterase activity, consistent with a cholinoceptive role. A probable source of cholinergic afferents is the pedunculopontine nucleus, which forms part of a prominent group of(More)
Extracellular recordings of single unit activity were made in the substantia nigra (SN) of chloral hydrate-anaesthetized rats. Dopaminergic neurones of the pars compacta (SNC) were stimulated by (-)-nicotine bitartrate (1.0 mg kg-1) given subcutaneously (s.c.). This action was prevented by the secondary amine mecamylamine HCl (2.0 mg kg-1 i.v.) but not by a(More)
The immunoperoxidase technique was used to study the effect of adrenalectomy on vasopressin (VP) immunoreactivity in the hypothalamic paraventricular nucleus of rat. In control animals, relatively few VP-immunostained parvocellular neurons were found in addition to a large population of magnocellular VP neurons. Seven to 14 days after bilateral(More)
The responses of dopamine cells in the substantia nigra to iontophoretically administered dopamine and intravenous apomorphine were compared to the responses of spontaneously active neurons in the caudate nucleus. Dopaminergic cells were six to ten times more sensitive to dopamine and intravenous apomorphine than 86 percent of the caudate cells tested. This(More)
Certain neurons in the brain are specifically and intensely stained by a histochemical method which demonstrates nicotinamide adenine dinucleotide phosphate NADPH-diaphorase activity. The cell types containing this enzyme in certain areas of the rat forebrain were examined by combining NADPH-diaphorase histochemistry with the indirect immunofluorescence(More)
Three groups of gamma-aminobutyric acid--containing neurons were found in the mammillary region of the posterior hypothalamus. The groups correspond to the tuberal, caudal, and postmammillary caudal magnocellular nuclei. Many cells in these nuclei were retrogradely labeled with fast blue after the injection of this fluorescent dye into the neocortex.(More)
Fine networks of phenylethanolamine N-methyltransferase (PNMT)-immunoreactive fibers are found in the hypothalamic paraventricular nucleus--mainly in the anterior, dorsal and dorso-medial parvicellular subdivisions, the lateral hypothalamus (dorsal, lateral and ventral to the fornix) and in the central amygdaloid nucleus. Coronal hemisections of the(More)
In this study, we investigated the effects of acute caffeine administration on the activity of midbrain dopamine neurons. Caffeine significantly depressed the firing rates of dopamine neurons in the ventral tegmental area (A10 group), but had no significant effect on the firing rates of dopamine neurons in the substantia nigra zona compacta (A9 group). The(More)