Baclofen administration alters fear extinction and GABAergic protein levels.
Neurobiol Learn Mem
; 98(3): 261-71, 2012 Oct.
Article
em En
| MEDLINE
| ID: mdl-23010137
ABSTRACT
The investigation of GABAergic systems in learning and extinction has principally focused on ionotropic GABA(A) receptors. Less well characterized is the metabotropic GABA(B) receptor, which when activated, induces a more sustained inhibitory effect and has been implicated in regulating oscillatory activity. Few studies have been carried out utilizing GABA(B) ligands in learning, and investigations of GABA(B) in extinction have primarily focused on interactions with drugs of abuse. The current study examined changes in GABA(B) receptor function using the GABA(B) agonist baclofen (2 mg/mL) or the GABA(B) antagonist phaclofen (0.3 mg/mL) on trace cued and contextual fear conditioning and extinction. The compounds were either administered during training and throughout extinction in Experiment 1, or starting 24 h after training and throughout extinction in Experiment 2. All drugs were administered 1 mL/kg via intraperitoneal injection. These studies demonstrated that the administration of baclofen during training and extinction trials impaired animals' ability to extinguish the fear association to the CS, whereas the animals that were administered baclofen starting 24 h after training (Experiment 2) did display some extinction. Further, contextual fear extinction was impaired by baclofen in both experiments. Tissue analyses suggest the cued fear extinction deficit may be related to changes in the GABA(B2) receptor subunit in the amygdala. The data in the present investigation demonstrate that GABA(B) receptors play an important role in trace cued and contextual fear extinction, and may function differently than GABA(A) receptors in learning, memory, and extinction.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Baclofeno
/
Condicionamento Psicológico
/
Extinção Psicológica
/
Medo
/
Agonistas dos Receptores de GABA-B
/
Ácido gama-Aminobutírico
Limite:
Animals
Idioma:
En
Revista:
Neurobiol Learn Mem
Assunto da revista:
BIOLOGIA
/
CIENCIAS DO COMPORTAMENTO
/
NEUROLOGIA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos