Involvement of dorsal hippocampus glutamatergic and nitrergic neurotransmission in autonomic responses evoked by acute restraint stress in rats.
Neuroscience
; 258: 364-73, 2014 Jan 31.
Article
em En
| MEDLINE
| ID: mdl-24269610
The dorsal hippocampus (DH) is a structure of the limbic system that is involved in emotional, learning and memory processes. There is evidence indicating that the DH modulates cardiovascular correlates of behavioral responses to stressful stimuli. Acute restraint stress (RS) is an unavoidable stress situation that evokes marked and sustained autonomic changes, which are characterized by elevated blood pressure (BP), intense heart rate (HR) increase and a decrease in cutaneous temperature. In the present study, we investigated the involvement of an N-methyl-D-aspartate (NMDA) glutamate receptor/nitric oxide (NO) pathway of the DH in the modulation of autonomic (arterial BP, HR and tail skin temperature) responses evoked by RS in rats. Bilateral microinjection of the NMDA receptor antagonist AP-7 (10 nmol/500 nL) into the DH attenuated RS-evoked autonomic responses. Moreover, RS evoked an increase in the content of NO2/NO3 in the DH, which are products of the spontaneous oxidation of NO under physiological conditions that can provide an indirect measurement of NO production. Bilateral microinjection of N-propyl-L-arginine (0.1 nmol/500 nL; N-propyl, a neuronal NO synthase (nNOS) inhibitor) or carboxy-PTIO (2 nmol/500 nL; c-PTIO, an NO scavenger) into the DH also attenuated autonomic responses evoked by RS. Therefore, our findings suggest that a glutamatergic system present in the DH is involved in the autonomic modulation during RS, acting via NMDA receptors and nNOS activation. Furthermore, the present results suggest that NMDA receptor/nNO activation has a facilitatory influence on RS-evoked autonomic responses.
Palavras-chave
2-amino-7-phosphonoheptanoic acid; ACSF; ANOVA; AP-7; BNST; BP; BSA; DH; HR; LSA; MAP; MPFC; N(ω)-propyl-l-arginine; N-methyl-d-aspartate; N-propyl; NADPH; NMDA; NO; RS; SEM; analysis of variance; artificial cerebrospinal fluid; bed nucleus of stria terminalis; blood pressure; bovine serum albumin; c-PTIO; carboxy-PTIO(S)-3-carboxy-4-hydroxyphenylglicine; dorsal hippocampus; glutamate; heart rate; hippocampus; l-glu; lateral septal area; mean arterial pressure; medial prefrontal cortex; nNOS; neuronal nitric oxide synthase; nitric oxide; reduced form of nicotinamide adenine dinucleotide phosphate; restraint stress; standard error of mean
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Estresse Psicológico
/
Receptores de N-Metil-D-Aspartato
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Hipocampo
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Óxido Nítrico
Limite:
Animals
Idioma:
En
Revista:
Neuroscience
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos