104) Glutamatergic ionotropic blockade within N. accumbens alters working memory and the endocytic machinery in areas of rat brain.

RUIZ, A.M.; BAIARDI, G.; BELING, A.; BORGONOVO, J.; MARTÍNEZ, G.; LANDA, A.I.; GARGIULO, P.A.; SOSA, M.A.

Mendoza.-

Congreso; XXVI Reunión Anual de la Sociedad de Biología de Cuyo. Mendoza, 5 a 7 de Diciembre de 2008.-; 2008

Sociedad de Biología de Cuyo. Mendoza, 5 a 7 de Diciembre de 2008.-

104) 2008. Ruiz, A.M.; Baiardi, G.; Beling, A.; Borgonovo, J.; Martínez, G.; Landa, A.I.; Gargiulo, P.A.; Sosa, M.A. Glutamatergic ionotropic blockade within N. accumbens alters working memory and the endocytic machinery in areas of rat brain. XXVI Reunión Anual de la Sociedad de Biología de Cuyo. Mendoza, 5 a 7 de Diciembre de 2008.-  The effects of NMDA and non-NMDA glutamatergic receptor blockade on performance in hole board test were studied in adult male Holtzman rats cannulated bilaterally into the nucleus accumbens (Acc). Rats (5 groups) received 1 mL injections of either saline, 0.5 or 1 mg of 2-amino-7-phosphonoheptanoic acid (AP-7) or 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo-(f)quinoxa-line-7-sulphonamide-disodium (NBQX) 10 min before testing. An increase in ambulatory movements (0.5 mg; p<0.05), non-ambulatory movements and number of movements (1 mg; p<0.05); sniffing and total exploration (1 mg; p<0.01) was observed with AP-7. NBQX did not induce behavioral changes.  The AP7 group increased the number of explorations to the first and second hole  (p<0.05 for 0.5 mg and p<0.001 for 1 mg vs saline group). When the second hole was compared with the first of its group, a difference was only seen in 1-mg AP-7 group (p<0.001). Increasing differences between the other holes and the first were observed with AP-7. AP-7 increased the coat protein AP-2 expression in Acc, but not AP-180, nor the synaptic protein synaptophysin. The increase of AP-2 by AP-7 was also observed in the medial prefrontal cortex.  No changes were observed with NBQX. NMDA glutamatergic blockade might induce activation of the endocytic machinery of Acc, leading to stereotypies and perseverations, lacking cortical intentional direction.