Interhemispheric regulation of the rat medial prefrontal cortical glutamate stress response: role of local GABA- and dopamine-sensitive mechanisms.
Psychopharmacology (Berl)
; 234(3): 353-363, 2017 Feb.
Article
em En
| MEDLINE
| ID: mdl-27822602
ABSTRACT
RATIONALE We previously reported that stressors increase medial prefrontal cortex (PFC) glutamate (GLU) levels as a result of activating callosal neurons located in the opposite hemisphere and that this PFC GLU stress response is regulated by GLU-, dopamine- (DA-), and GABA-sensitive mechanisms (Lupinsky et al. 2010). OBJECTIVES:
Here, we examine the possibility that PFC DA regulates the stress responsivity of callosal neurons indirectly by acting at D1 and D2 receptors located on GABA interneurons.METHODS:
Microdialysis combined with drug perfusion (reverse dialysis) or microinjections was used in adult male Long-Evans rats to characterize D1, D2, and GABAB receptor-mediated regulation of the PFC GABA response to tail-pinch (TP) stress.RESULTS:
We report that TP stress reliably elicited comparable increases in extracellular GABA in the left and right PFCs. SCH23390 (D1 antagonist; 100 µM perfusate concentration) perfused by reverse microdialysis attenuated the local GABA stress responses equally in the left and right PFCs. Intra-PFC raclopride perfusion (D2 antagonist; 100 µM) had the opposite effect, not only potentiating the local GABA stress response but also causing a transient elevation in basal (pre-stress) GABA. Moreover, unilateral PFC raclopride microinjection (6 nmol) attenuated the GLU response to TP stress in the contralateral PFC. Finally, intra-PFC baclofen perfusion (GABAB agonist; 100 µM) inhibited the local GLU and GABA stress responses.CONCLUSIONS:
Taken together, these findings implicate PFC GABA interneurons in processing stressful stimuli, showing that local D1, D2, and GABAB receptor-mediated changes in PFC GABA transmission play a crucial role in the interhemispheric regulation of GLU stress responsivity.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estresse Psicológico
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Dopamina
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Receptores de Dopamina D2
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Receptores de Dopamina D1
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Córtex Pré-Frontal
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Ácido Glutâmico
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Ácido gama-Aminobutírico
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Interneurônios
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
Idioma:
En
Revista:
Psychopharmacology (Berl)
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Canadá