Kivonat:
Secretin and its receptors show wide distribution in the central
nervous system. It was demonstrated previously that intravenous
(i.v.) and intracerebroventricular (i.c.v.) application of
secretin influenced the behavior of rat, mouse, and human. In
our previous experiment, we used a special animal model,
Japanese waltzing mice (JWM). These animals run around without
stopping (the ambulation distance is very limited) and they do
not bother with their environment. The i.c.v. secretin
attenuated this hyperactive repetitive movement. In the present
work, the effect of i.c.v. and intranasal (i.n.) application of
secretin was compared. We have also looked for the presence of
secretin receptors in the brain structures related to motor
functions. Two micrograms of i.c.v. secretin improved the
horizontal movement of JWM, enhancing the ambulation distance.
It was nearly threefold higher in treated than in control
animals. The i.n. application of secretin to the left nostril
once or twice a day or once for 3 days more effectively
enhanced the ambulation distance than i.c.v. administration.
When secretin was given twice a day for 3 days it had no effect.
Secretin did not improve the explorative behavior (the rearing),
of JWM. With the use of in situ hybridization, we have found
very dense secretin receptor labeling in the cerebellum. In the
primary motor cortex and in the striatum, only a few labeled
cells were seen. It was supposed that secretin exerted its
effect through specific receptors, mainly present in the
cerebellum.
