Central GABAergic innervation of the pituitary in goldfish: a radioautographic and immunocytochemical study at the electron microscope level

Journal Article · Tue Sep 01 04:00:00 EDT 1987 · Gen. Comp. Endocrinol.; (United States)

DOI:https://doi.org/10.1016/0016-6480(87)90186-9· OSTI ID:5786181

Kah, O; Dubourg, P; Martinoli, M G; Rabhi, M; Gonnet, F; Geffard, M; Calas, A

The GABAergic innervation of the goldfish pituitary was studied at the light and electron microscope levels by means of radioautography after in vitro incubation in tritiated gamma-aminobutyric acid (GABA) and immunocytochemistry using antibodies against GABA. Following incubation of pituitary fragments in a medium containing tritiated GABA, a selective uptake of the tracer was observed within the digitations of the neurohypophysis. Silver grain clusters were also observed in the adenohypophyseal tissue. At the electron microscope level, this uptake was found to correspond to nerve endings containing small clear and dense-core vesicles. These labeled profiles were located mainly in neurohypophyseal digitations in close apposition with the basement membrane separating the neurohypophysis from the adenohypophysis. However, they were also encountered in direct contact with most adenohypophyseal cell types in the different lobes. These results were confirmed by immunocytochemical data demonstrating the presence of numerous GABA immunoreactive fibers in both anterior and neurointermediate lobes. They were found either in the digitations of the neurohypophysis or in the adenohypophysis in direct contact with the glandular cells with a distribution and an ultrastructural aspect similar to those observed by radioautography. These data demonstrate that the pituitary of teleosts receives a massive GABAergic innervation. Although physiological data providing a functional significance for such an innervation are lacking, the present study suggests that, as already documented in mammals, GABA may be involved in the neuroendocrine regulation of pituitary functions in teleosts.

• Research Organization: Laboratoire de Physiologie des Interactions Cellulaires, Talence, France
• OSTI ID: 5786181
• Journal Information: Gen. Comp. Endocrinol.; (United States), Journal Name: Gen. Comp. Endocrinol.; (United States) Vol. 67:3; ISSN GCENA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
AMINOBUTYRIC ACID
ANIMALS
AQUATIC ORGANISMS
AUTONOMIC NERVOUS SYSTEM AGENTS
AUTORADIOGRAPHY
BIOLOGICAL FUNCTIONS
BODY
CARBOXYLIC ACIDS
CYTOLOGICAL TECHNIQUES
DRUGS
ELECTRON MICROSCOPY
ENDOCRINE GLANDS
FISHES
FUNCTIONS
GLANDS
GOLDFISH
IMMUNE REACTIONS
LABELLED COMPOUNDS
MICROSCOPY
MOLECULAR STRUCTURE
NEUROREGULATORS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PITUITARY GLAND
STRUCTURE-ACTIVITY RELATIONSHIPS
TRITIUM COMPOUNDS
VERTEBRATES