GABA(A) ρ receptor mechanisms in the rat amygdala and its role in the modulation of fear and anxiety.
BACKGROUND
Accumulating evidence for the presence of GABA(A) ρ receptors within the amygdala which differ from other members of the GABA(A) receptor family in both subunit composition and functional properties has been recently obtained.


OBJECTIVE
This work was conducted to study whether GABA(A) ρ receptors may have a putative role in the amygdaloid modulation of fear and anxiety.


RESULTS
It was found that the bilateral intra-amygdaloid administration (6-240 pmol/side) of (1,2,5,6-tetrahydropyridine-4-yl)methylphosphinic acid, a selective GABA(A) ρ receptor antagonist, reduced dose-dependently the exploration of the open arms of the elevated plus-maze without affecting locomotion and increased the plasma levels of corticosterone. In contrast, bicuculline in the dose range used (1.8-60 pmol/side) induced seizures, but had no effects on the exploration of the maze.


CONCLUSIONS
It is suggested that GABA(A) ρ receptors may have a role in the amygdaloid modulation of fear and anxiety.
Flores-Gracia
Candy
C
Division of Neurosciences, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-253, 04510, Mexico City, Mexico.
Nuche-Bricaire
Avril
A
Crespo-Ramírez
Minerva
M
Miledi
Ricardo
R
Fuxe
Kjell
K
Pérez de la Mora
Miguel
M
D000679:Amygdala / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001007:Anxiety / Q000378:metabolism*; D001522:Behavior, Animal / Q000187:drug effects; D001640:Bicuculline / Q000008:administration & dosage / Q000009:adverse effects; D003345:Corticosterone / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects; D005239:Fear / Q000187:drug effects; D058787:GABA-A Receptor Antagonists / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D017551:Microdialysis; D009043:Motor Activity / Q000187:drug effects; D010721:Phosphinic Acids / Q000008:administration & dosage; D011725:Pyridines / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism*; D012640:Seizures / Q000139:chemically induced
C101879:(1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid; D058787:GABA-A Receptor Antagonists; D010721:Phosphinic Acids; D011725:Pyridines; D011963:Receptors, GABA-A; D003345:Corticosterone; D001640:Bicuculline