Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Lasting reduction in mesolimbic dopamine neuronal activity after morphine withdrawal
Autore:
Diana, M; Muntoni, AL; Pistis, M; Melis, M; Gessa, GL;
Indirizzi:
Univ Sassari, Dept Drug Sci, I-07100 Sassari, Italy Univ Sassari SassariItaly I-07100 Dept Drug Sci, I-07100 Sassari, Italy Univ Cagliari, Bb Brodie Dept Neurosci, I-09124 Cagliari, Italy Univ Cagliari Cagliari Italy I-09124 t Neurosci, I-09124 Cagliari, Italy
Titolo Testata:
EUROPEAN JOURNAL OF NEUROSCIENCE
fascicolo: 3, volume: 11, anno: 1999,
pagine: 1037 - 1041
SICI:
0953-816X(199903)11:3<1037:LRIMDN>2.0.ZU;2-D
Fonte:
ISI
Lingua:
ENG
Soggetto:
NUCLEUS-ACCUMBENS; PRECIPITATED WITHDRAWAL; RATS; SENSITIZATION; ETHANOL; ABSTINENCE; DEPENDENCE; RELEASE; TRANSMISSION; ACTIVATION;
Keywords:
dopamine; drug addiction; electrophysiology; morphine; nucleus accumbens; opiate withdrawal;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
39
Recensione:
Indirizzi per estratti:
Indirizzo: Diana, M Univ Sassari, Dept Drug Sci, Via Muroni 23-A, I-07100 Sassari, Italy Univ Sassari Via Muroni 23-A Sassari Italy I-07100 assari, Italy
Citazione:
M. Diana et al., "Lasting reduction in mesolimbic dopamine neuronal activity after morphine withdrawal", EUR J NEURO, 11(3), 1999, pp. 1037-1041

Abstract

The activity of mesolimbic dopaminergic neurons was investigated in rats at various times after a chronic regimen of morphine, which produced, upon suspension, a marked somatic withdrawal syndrome. Single-cell extracellular recording techniques, coupled with antidromic identification from the nucleus accumbens, were used to monitor neuronal activity while behavioural observations allowed quantification of the somatic signs of morphine withdrawal. Temporal correlation of electrophysiological indices, such as firing rateand burst firing, with scores obtained through behavioural assessments proved negative, in that somatic signs were pronounced at 24 h after suspension of treatment and then subsided to control values at 72 h after the last morphine injection. In contrast, the firing rate and burst firing of mesolimbic dopaminergic neurons were found to be reduced at 1, 3 and 7 days after morphine withdrawal. After 14 drug-free days, electrophysiological analysisrevealed an apparent normalization of various parameters. However, at thistime, intravenous administration of morphine produced an increment of electrical activity which was significantly higher than that obtained in control (saline treated) rats. Further, administration of the opiate antagonist naltrexone, administered without prior morphine, at 3, 7 and 14 days after the last morphine administration, failed to alter dopaminergic neuronal activity. The results indicate: (i) that the activity of mesolimbic dopaminergic neurons remains reduced well after somatic signs of withdrawal have disappeared; (ii) after 14 days of withdrawal, the augmented magnitude of the electrophysiological response to exogenous morphine suggests an increased sensitivity of opiate receptors; and (iii) the lack of relationship between dopaminergic activity and somatic signs of withdrawal corroborates the notionthat dopaminergic activity in the mesolimbic system does not participate in the neurobiological mechanisms responsible for somatic withdrawal. The present results may be relevant to the phenomenon of drug addiction in humansand consequent relapse after drug-free periods.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 09/04/20 alle ore 12:35:31