Effects of dopamine, D-1 and D-2 dopaminergic agonists on the excitability of hippocampal CA1pyramidal cells in guinea pig

✍ Scribed by N. Berretta; F. Berton; R. Bianchi; M. Capogna; W. Francesconi; M. Brunelli

• Publisher: Springer-Verlag
• Year: 1990
• Tongue: English
• Weight: 665 KB
• Volume: 83
• Category: Article
• ISSN: 0014-4819
• DOI: 10.1007/bf00232200

✦ Synopsis

In hippocampal pyramidal cells (HPCs), Dopamine (DA) application (1 microM) produced, in 50% of recorded cells, an hyperpolarization of the resting membrane potential (r.m.p.) and an increase of the afterhyperpolarization (AHP) amplitude and duration in 79% of recorded cells. DA-induced effects on both the r.m.p. and AHP were mimicked by bath application of a D-1 selective agonist, SKF 38393 (20 microM). In addition, we have observed that a D-1 selective antagonist such as SCH 23390 (1 microM) abolished the action of both DA and SKF 38393. In contrast, the activation of D-2 receptors through LY 171555 (10 microns) produced, in 50% of cells, a depolarization of the r.m.p. and a depression of the AHP in 67% of recorded cells. These results suggest that the effects observed in hippocampal pyramidal neurons after DA application of micromolar concentration are mediated by D-1 subtype of receptors.