The stimulation of glutamate receptors plays a relevant role in the development of behavioral sensitization to psychostimulants, while less clear results have been obtained on their role in morphine sensitization. We addressed this issue by comparing the development of cocaine and morphine sensitization under a continuous s.c. infusion of the N-methyl-D-aspartate (NMDA) antagonist dizocilpine (0.1 mg/kg/24 h). Moreover, we studied the expression of NMDA and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor subunits in discrete limbic areas of rats sensitized to morphine or cocaine with or without the concomitant dizocilpine infusion. It was observed that dizocilpine infusion did not prevent the development of morphine sensitization, while it prevented the development of tolerance to morphine-induced analgesia. Finally, morphine-sensitized animals did not present any modification in the subunit expression of glutamate receptors in the brain areas examined. In agreement with previous results, we found that dizocilpine infusion prevented the development of cocaine sensitization. Moreover, we observed that rats sensitized to cocaine presented a significant increase in the levels of GLUR1, NR1 and NR2B, in the nucleus accumbens, and of NR2B in the hippocampus compared to control animals. Such modifications were absent in rats administered cocaine under dizocilpine infusion. We conclude that: (i) morphine sensitization is a neuroadaptive phenomenon which does not appear to require NMDA receptor activity in order to develop; (ii) cocaine sensitization is clearly dependent on NMDA receptor activity, as dizocilpine infusion prevented the occurrence of glutamate receptors modifications as well as the development of sensitization.

Scheggi, S., Mangiavacchi, S., Masi, F., Gambarana, C., Tagliamonte, A., DE MONTIS, M.G. (2002). Dizocilpine infusion has a different effect in the development of morphine and cocaine sensitization: behavioral and neurochemical aspects. NEUROSCIENCE, 109(2), 267-274 [10.1016/S0306-4522(01)00483-3].

Dizocilpine infusion has a different effect in the development of morphine and cocaine sensitization: behavioral and neurochemical aspects

SCHEGGI, S.;MANGIAVACCHI, S.;MASI, F.;GAMBARANA, C.;TAGLIAMONTE, A.;DE MONTIS, M. G.
2002-01-01

Abstract

The stimulation of glutamate receptors plays a relevant role in the development of behavioral sensitization to psychostimulants, while less clear results have been obtained on their role in morphine sensitization. We addressed this issue by comparing the development of cocaine and morphine sensitization under a continuous s.c. infusion of the N-methyl-D-aspartate (NMDA) antagonist dizocilpine (0.1 mg/kg/24 h). Moreover, we studied the expression of NMDA and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor subunits in discrete limbic areas of rats sensitized to morphine or cocaine with or without the concomitant dizocilpine infusion. It was observed that dizocilpine infusion did not prevent the development of morphine sensitization, while it prevented the development of tolerance to morphine-induced analgesia. Finally, morphine-sensitized animals did not present any modification in the subunit expression of glutamate receptors in the brain areas examined. In agreement with previous results, we found that dizocilpine infusion prevented the development of cocaine sensitization. Moreover, we observed that rats sensitized to cocaine presented a significant increase in the levels of GLUR1, NR1 and NR2B, in the nucleus accumbens, and of NR2B in the hippocampus compared to control animals. Such modifications were absent in rats administered cocaine under dizocilpine infusion. We conclude that: (i) morphine sensitization is a neuroadaptive phenomenon which does not appear to require NMDA receptor activity in order to develop; (ii) cocaine sensitization is clearly dependent on NMDA receptor activity, as dizocilpine infusion prevented the occurrence of glutamate receptors modifications as well as the development of sensitization.
Scheggi, S., Mangiavacchi, S., Masi, F., Gambarana, C., Tagliamonte, A., DE MONTIS, M.G. (2002). Dizocilpine infusion has a different effect in the development of morphine and cocaine sensitization: behavioral and neurochemical aspects. NEUROSCIENCE, 109(2), 267-274 [10.1016/S0306-4522(01)00483-3].
File in questo prodotto:
File Dimensione Formato  
dizocilpine.pdf

non disponibili

Tipologia: Post-print
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 258.99 kB
Formato Adobe PDF
258.99 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/21469
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo