Kivonat:
Secretin shows a wide distribution in the brain. Functional
significance of central secretin is stressed since it has been
associated with autism and schizophrenia. The presence of the
secretin receptor was previously demonstrated in the brain by
different methods. Neurons in the cerebellum, hypothalamic
paraventricular and supraoptic nuclei, and in the vascular organ
of lamina terminalis were shown to express secretin receptor
mRNA by using in situ hybridization with digoxigenin-labeled
probe. In this work, we used a very sensitive radioactive in
situ hybridization technique and systematically mapped the
expression of secretin receptor mRNA in the brain. The densest
labeling was observed in the nucleus of solitary tract and in
the laterodorsal thalamic nucleus, where decreasing number of
receptors was seen in the vascular organ of lamina terminalis,
and the lateral habenular complex, and then in the supraoptic
nucleus. Only a few scattered labeled cells were observed in the
median frontal gyrus, entorhinal cortex, hypothalamic
paraventricular nucleus, perifornical region, lateral
hypothalamic area, head of the caudate nucleus, spinal
trigeminal nucleus, and cerebellum. Secretin receptor mRNA
showed a far wider distribution than was known before,
suggesting a more significant functional relevance than thought
earlier.