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Titolo:
Lesion of the ventral periaqueductal gray reduces conditioned fear but does not change freezing induced by stimulation of the dorsal periaqueductal gray
Autore:
Vianna, DML; Graeff, FG; Landeira-Fernandez, J; Brandao, ML;
Indirizzi:
Univ Sao Paulo, Lab Psiobiol, Fac Filosophia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, Brazil Univ Sao Paulo Ribeirao Preto Brazil BR-14040901 BCibeirao Preto, Brazil Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Neurol Psiquiat & Psicol Med,BR-14049900 Ribeirao Preto, Sao Paulo, Brazil Univ Sao Paulo Ribeirao Preto Sao Paulo Brazil BR-14049900 BCaulo, Brazil Pontificia Univ Catolica Rio de Janeiro, Dept Psicol, Lab Neurociencias & Comportamento, Rio De Janeiro, Brazil Pontificia Univ Catolica Rio de Janeiro Rio De Janeiro Brazil o, Brazil Univ Estacio Sa, Lab Psicol Comparada, BR-22631021 Rio De Janeiro, Brazil Univ Estacio Sa Rio De Janeiro Brazil BR-22631021 BCo De Janeiro, Brazil
Titolo Testata:
LEARNING & MEMORY
fascicolo: 3, volume: 8, anno: 2001,
pagine: 164 - 169
SICI:
1072-0502(200105/06)8:3<164:LOTVPG>2.0.ZU;2-W
Fonte:
ISI
Lingua:
ENG
Soggetto:
MIDBRAIN CENTRAL GRAY; DEFENSIVE BEHAVIOR; ELECTRICAL-STIMULATION; SUBSTANTIA-NIGRA; RAT; TECTUM; MICROINJECTIONS; ORGANIZATION; EXPRESSION; COLLICULUS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
29
Recensione:
Indirizzi per estratti:
Indirizzo: Brandao, ML Univ Sao Paulo, Lab Psiobiol, Fac Filosophia Ciencias & LetrasRibeirao Preto, BR-14040901 Ribeirao Preto, Brazil Univ Sao Paulo Ribeirao Preto Brazil BR-14040901 BCo, Brazil
Citazione:
D.M.L. Vianna et al., "Lesion of the ventral periaqueductal gray reduces conditioned fear but does not change freezing induced by stimulation of the dorsal periaqueductal gray", LEARN MEM, 8(3), 2001, pp. 164-169

Abstract

Previously-reported evidence showed that freezing to a context previously associated with footshock is impaired by lesion of the ventral periaqueductal gray (vPAG). It has also been shown that stepwise increase in the intensity of the electrical stimulation of the dorsal periaqueductal gray (dPAG) produces alertness, then freezing, and finally escape. These aversive responses are mimicked by microinjections of GABA receptor antagonists, such as bicuculline, or blockers of the glutamic acid decarboxylase (GAD), such as semicarbazide. into the dPAG. In this work, we examined whether the expression of these defensive responses could be the result of activation of ventral portion of the periaqueductal gray. Sham- or vPAG electrolytic-lesioned rats were implanted with an electrode in the dPAG for the determination of the thresholds of freezing and escape responses. The VPAG electrolytic lesions were behaviorally verified through a context-conditioned fear paradigm. Results indicated that lesion of the vPAG disrupted conditioned freezing response to contextual cues associated with footshocks but did not change the dPAG electrical stimulation for freezing and escape responses. In a second experiment, lesion of the vPAG also did not change the amount of freezingand escape behavior produced by microinjections of semicarbazide into the dPAG. These findings indicate that freezing and escape defensive responses induced by dPAG stimulation do not depend on the integrity of the vPAG. A discussion on different neural circuitries that might underlie different inhibitory and active defensive behavioral patterns that animals display during threatening situations is presented.

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Documento generato il 19/01/20 alle ore 00:28:22