A role for the angiotensin AT4 receptor subtype in overcoming scopolamine-induced spatial memory deficits.
Regul Pept
; 102(2-3): 147-56, 2001 Dec 15.
Article
en En
| MEDLINE
| ID: mdl-11730987
There is increasing interest in the role of the brain angiotensin AT4 receptor subtype in cognitive processing. This receptor subtype is activated by angiotensin IV (AngIV), is heavily distributed in the mammalian hippocampus, neocortex, and cerebellum, and has been linked with a learning and memory function. The present investigation utilized intracerebroventricular (i.c.v.)-infused scopolamine hydrobromide (scop), a muscarinic receptor antagonist, to disrupt acquisition of the circular water maze task of spatial memory. All animals received 2 days of training trials (five trials/day) using a visible platform in an effort to preclude subsequent confounding by scopolamine-induced sensory and/or motor impairments. In the first experiment, i.c.v.-infused scopolamine (70 nmol) was followed by 0, 10, 100, or 1000 pmol i.c.v. doses of Nle(1)-AngIV in separate groups of rats. Results indicated that each dose of Nle(1)-AngIV improved the poor acquisition of this task induced by scopolamine treatment. However, the 100- and 1000-pmol doses were most effective with respect to latency and distance to find the submerged pedestal. A second experiment demonstrated that treatment with a specific AT4 receptor antagonist, Nle(1), Leual(3)-AngIV (1000 pmol), blocked the ability of Nle(1)-AngIV (100 pmol) to improve the performance of scopolamine-compromised rats. These results support the notion that hippocampal AT4 receptors are involved in spatial memory processing, and that activation of these binding sites can overcome the disruption of spatial memory accompanying treatment with a muscarinic receptor antagonist.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Escopolamina
/
Receptores de Angiotensina
/
Trastornos de la Memoria
Límite:
Animals
Idioma:
En
Revista:
Regul Pept
Año:
2001
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Países Bajos