The effects of local perfusion with the dopamine D1 receptor antagonist SCH 23390 and the dopamine D2 receptor antagonist raclopride on basal and N-methyl-D-aspartate (NMDA) stimulated dopamine, γ-aminobutyric acid (GABA) and glutamate levels in the dorsolateral striatum were monitored using in vivo microdialysis anaesthetized rat. Local perfusion (90 min) with SCH 23390 and raclopride (1 and 10 μM) dose dependently increased basal striatal dopamine release whereas GABA and glutamate dialysate levels were unaffected. Local perfusion (10 min) with the 1 mM concentration of NMDA increased striatal dopamine, GABA and glutamate outflow. However, when perfused together with SCH 23390 (1 μM) NMDA inhibited glutamate efflux. Moreover, in the presence of SCH 23390 (10 μM) the NMDA induced rise in dopamine and GABA levels was partly prevented. On the other hand, raclopride 1 μM enhanced the NMDA stimulated GABA efflux while at 10 μM it partly counteracted the NMDA induced dopamine release. Thes...
Dopamine D1 and D2 receptor antagonism differentially modulates stimulation of striatal neurotransmitter levels by N-methyl-D-aspartic acid
MORARI, Michele;
1994
Abstract
The effects of local perfusion with the dopamine D1 receptor antagonist SCH 23390 and the dopamine D2 receptor antagonist raclopride on basal and N-methyl-D-aspartate (NMDA) stimulated dopamine, γ-aminobutyric acid (GABA) and glutamate levels in the dorsolateral striatum were monitored using in vivo microdialysis anaesthetized rat. Local perfusion (90 min) with SCH 23390 and raclopride (1 and 10 μM) dose dependently increased basal striatal dopamine release whereas GABA and glutamate dialysate levels were unaffected. Local perfusion (10 min) with the 1 mM concentration of NMDA increased striatal dopamine, GABA and glutamate outflow. However, when perfused together with SCH 23390 (1 μM) NMDA inhibited glutamate efflux. Moreover, in the presence of SCH 23390 (10 μM) the NMDA induced rise in dopamine and GABA levels was partly prevented. On the other hand, raclopride 1 μM enhanced the NMDA stimulated GABA efflux while at 10 μM it partly counteracted the NMDA induced dopamine release. Thes...I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
