Shock-induced hyperalgesia: II. Role of the dorsolateral periaqueductal gray.
Behav Neurosci
; 113(3): 539-49, 1999 Jun.
Article
em En
| MEDLINE
| ID: mdl-10443780
ABSTRACT
Exposure to 3 moderately intense (1-mA) tailshocks has been shown to lower vocalization thresholds to both heat and shock. Previous shock exposure also facilitates the acquisition of conditioned fear as measured by freezing. These observations suggest that shock induces hyperalgesia (enhanced pain). This study explored whether shock-induced hyperalgesia depends on neurons within rostral or caudal portions of the dorsolateral periaqueductal gray (dlPAG). Experiment 1 examined the impact of dlPAG lesions on the acquisition of conditioned fear. Sham-operated rats demonstrated enhanced acquisition after shock exposure; both rostral and caudal lesions eliminated this effect. Experiment 2 showed that tailshock lowered vocalization thresholds to heat in sham-operated but not lesioned subjects. These results suggest that the dlPAG plays a critical role in the production of shock-induced hyperalgesia.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Substância Cinzenta Periaquedutal
/
Limiar da Dor
/
Condicionamento Clássico
/
Eletrochoque
/
Medo
/
Temperatura Alta
/
Rede Nervosa
Limite:
Animals
Idioma:
En
Revista:
Behav Neurosci
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Estados Unidos