The effects of concurrent D-1 and D-2 dopamine receptor blockade with sch 23390 and eticlopride, on bombesin-induced behaviours

Document Type



Brain and Mind Institute


Hugh Piggins and Zulfiquar Merali. The effects of concurrent D−1 and D−2 dopamine receptor blockade with SCH 23390 and eticlopride, on bombesin-induced behaviours. Prog. Neuro-Psychopharmacol. & Biol. Psychiat. 1989, 13" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 16.2px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">13: 583–594.

1. The objective of the current study was to assess the effect of concurrent D−1 and D−2 receptor blockade on bombesin (BN)-induced grooming and locomotion on the premise that dopamine could be mediating the behavioural effects of BN.

2. Rats implanted with ventricular cannulae were pretretreated systemically with SCH 23390 and/or eticlopride (ETIC) followed by BN (0.5 ug/3 ul; i.c.v.). Grooming and locomotory activity were assessed for 60 min.

3. Individually, SCH 23390 (0.033 mg/kg) and ETIC (0.05 mg/kg) significantly inhibited BN-elicited grooming but not locomotion. Combining ETIC (0.05-0.1 mg/kg) with the fixed dose of SCH 23390 (0.033 mg/kg) significantly inhibited both behaviours in a dose dependent manner with a greater effect on locomotion. Adding SCH 23390 (0.033–0.075 mg/kg) to ETIC (0.05 mg/kg) inhibited both behaviours in a dose dependent manner with a more pronounced effect on grooming. At the combination dosages utilized, SCH 23390 and/or ETIC failed to significantly alter baseline behaviours in control conditions. It is thus concluded that both dopamine receptor subtypes are involved in the expression of BN-induced behaviours with D−1 appearing to have a greater involvement with grooming and D−2 locomotion.


This work was published before the author joined Aga Khan University.

Publication (Name of Journal)

Progress in Neuro-Psychopharmacology and Biological Psychiatry