CSF-contacting and other somatostatin-immunoreactive neurons in the brains of Anguilla anguilla, Phoxinus phoxinus, and Salmo gairdneri (Teleostei)

Cell Tissue Res. 1983;233(2):319-34. doi: 10.1007/BF00238299.

Abstract

A system of somatostatin-immunoreactive neurons was demonstrated in the brains of the eel, Anguilla anguilla, the European minnow, Phoxinus phoxinus, and the rainbow trout, Salmo gairdneri, by means of the light-microscopic indirect immunoperoxidase technique. In the anterior periventricular nucleus, somatostatin-immunoreactive cerebrospinal fluid (CSF)-contacting neurons display intensely stained intraventricular dendritic protrusions, perikarya, and axonal processes. The latter taper into a somatostatin-immunoreactive fiber plexus extending to the infundibulum, the proximal neurohypophysis, and the lateral and mammillary recesses. In addition, somatostatin-immunoreactive neurons were demonstrated in the magnocellular preoptic, entopeduncular and dorsolateral thalamic nuclei, further in the pretectal area and the ventrolateral tegmentum. Somatostatin-immunoreactive fiber bundles project via the stria medullaris toward the habenular nucleus; they also course in the dorsomedial-ventrolateral direction at the level of the pretectal-tegmental area, and within the ventral and dorsal tegmentum. The presence of somatostatin in a variety of different neurons of the teleost brain is discussed in connection with their tentative inhibitory function. The CSF-contacting neurons of the anterior periventricular nucleus are supposed to function as sensors that pass information from the CSF to the somatostatin system of the hypothalamus and/or other components of the neuroendocrine apparatus.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Chemistry*
  • Cyprinidae / physiology
  • Diencephalon / analysis
  • Eels / physiology
  • Fishes / physiology*
  • Immunoenzyme Techniques
  • Mesencephalon / analysis
  • Neurons / analysis
  • Somatostatin / analysis*
  • Somatostatin / cerebrospinal fluid
  • Species Specificity
  • Trout / physiology

Substances

  • Somatostatin