Simultaneous immunogold labeling of GABAergic terminals and vasopressin-containing neurons in the rat paraventricular nucleus.
The GABAergic innervation of vasopressin-containing cells in the magnocellular part of the paraventricular nucleus was studied at the electron-microscope level using antibodies against GABA and vasopressin. The detection of both GABA and vasopressin on the same ultrathin section, performed with a double-labeling immunogold method, revealed GABAergic terminals in symmetrical synaptic contact with vasopressin-containing neurons. These GABAergic terminals displayed mitochondria, clear synaptic vesicles and varying numbers of electron-dense vesicles. Vasopressin-immunoreactivity was associated with neurosecretory granules, whereas GABA-immunoreactivity was found above mitochondria, clear synaptic vesicles and some electron-dense vesicles. This study, demonstrating the extensive participation of GABA in the innervation of magnocellular vasopressin-secreting neurons, suggests that this inhibitory neurotransmitter regulates vasopressin secretion at the level of the paraventricular nucleus.
Decavel
C
C
Laboratoire de Physiologie des Interactions Cellulaires, UA CNRS 339, Université de Bordeaux I, Talence, France.
Dubourg
P
P
Leon-Henri
B
B
Geffard
M
M
Calas
A
A
D000818:Animals; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron / Q000379:methods; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000378:metabolism / Q000648:ultrastructure; D014667:Vasopressins / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D014667:Vasopressins; D005680:gamma-Aminobutyric Acid