Monoamine innervation of the organum vasculosum laminae terminalis (OVLT): a high resolution radioautographic study in the rat
The monoamine innervation of the organum vasculosum laminae terminalis (OVLT) was examined in the adult rat by light and electron microscope radioautography after intraventricular administration of tritiated serotonin (( 3H)5-HT) or dopamine (( 3H)DA). Radioautographic and biochemical controls after 5,7-dihydroxytryptamine or 6-hydroxydopamine lesioning established the respective serotonin (5-HT) and catecholamine (CA) identities of the axonal varicosities labeled under the conditions of the present experiments. For descriptive purposes, the OVLT was subdivided in three parts: two parenchymal zones, one juxtaventricular, the other juxtavascular, and the vascular core. Almost 10% of all axonal varicosities in the OVLT were found to be labeled with (3H)5-HT. This 5-HT innervation was most prominent in the rostrocaudal and ventrodorsal portions of the juxtaventricular zone and the dorsal aspect of the juxtavascular zone; there was none in the vascular core. (3H)DA-labeled varicosities were much less abundant and yet more numerous than earlier histofluorescent and immunohistochemical studies would have predicted. They predominated in the juxtavascular zone, where a majority presumably had a dopamine (DA) rather than a noradrenaline identity. Some were also found in the vascular core, where they most likely corresponded to peripheral autonomic noradrenaline endings. In the juxtaventricular zone of the OVLT, a significant proportion of the (3H)5-HT-labeled varicosity profiles could be observed to form axodendritic synapses, but in the juxtavascular zone no 5-HT or any (3H)DA-labeled ones were ever seen in synaptic junction. In the juxtavascular zone, the 5-HT and the presumed DA endings established close relationships with neurosecretory axons, and with astrocytic or tanycytic processes on which they occasionally formed synaptoid contacts.
- Research Organization:
- Laboratoire de Neurobiologie, C.N.R.S. Marseille (France)
- OSTI ID:
- 6691775
- Journal Information:
- J. Comp. Neurol.; (United States), Vol. 272:4
- Country of Publication:
- United States
- Language:
- English
Similar Records
Quantified regional and laminar distribution of the noradrenaline innervation in the anterior half of the adult rat cerebral cortex
Autoradiographic localization of relaxin binding sites in rat brain
Related Subjects
DOPAMINE
TISSUE DISTRIBUTION
NERVES
AUTORADIOGRAPHY
SEROTONIN
RATS
TRITIUM COMPOUNDS
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
AZOLES
CARDIOTONICS
CARDIOVASCULAR AGENTS
DISTRIBUTION
DRUGS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INDOLES
LABELLED COMPOUNDS
MAMMALS
NERVOUS SYSTEM
NEUROREGULATORS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENOLS
POLYPHENOLS
PYRROLES
RADIOPROTECTIVE SUBSTANCES
RODENTS
SYMPATHOMIMETICS
TRYPTAMINES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques