Hypothalamo-preoptic histaminergic projections in sleep-wake control in the cat.
Eur J Neurosci
; 6(4): 618-25, 1994 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-8025714
ABSTRACT
Cats were chronically implanted with electrodes for polygraphic recordings and cannulae for intracerebral microinjections in order to study the functional role of histaminergic innervation of the preoptic-anterior hypothalamus in sleep-wake control. alpha-Fluoromethylhistidine (alpha FMH, 50 micrograms in 1 microliter), a specific inhibitor of the histamine-synthesizing enzyme, when injected bilaterally into the preoptic area, where numerous histaminergic fibres and terminal-like structures are present, caused a significant increase in deep slow wave sleep (S2) and paradoxical sleep (PS) and a decrease in wakefulness. In contrast, microinjections of histamine (5 or 30 micrograms in 1 microliter) in the same area dose-relatedly increased wakefulness and decreased both slow wave sleep and paradoxical sleep. The effects of histamine were reduced by pretreatment with mepyramine (1 mg/kg i.p.), a well known histamine H1 receptor antagonist, and were mimicked by a local injection of impromidine (1 microgram in 1 microliter), a potent histamine H2 receptor agonist. Microinjections of mepyramine alone (120 micrograms in 1 microliter) caused an increase in slow wave sleep. These results suggest that preoptic histaminergic innervation is involved in sleep-wake control and that the action might be mediated via both H1 and H2 receptors.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Área Pré-Óptica
/
Sono
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Vigília
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Encéfalo
/
Hipotálamo Anterior
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Histamina
/
Gatos
Limite:
Animals
Idioma:
En
Revista:
Eur J Neurosci
Ano de publicação:
1994
Tipo de documento:
Article