Dopamine receptor antagonists prevent the d-amphetamine-induced increase in calcitonin gene-related peptide levels in ventral striatum

✍ Scribed by Susanne H.M. Gruber; George G. Nomikos; Aleksander A. Mathé

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 102 KB
• Volume: 64
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.1113

✦ Synopsis

Abstract

Microdialysis in conjunction with radioimmunoassay (RIA) were used to study the effects of acute d‐amphetamine or dopamine (DA) receptor antagonists administration on extracellular concentrations of calcitonin gene‐related peptide (CGRP) in the ventral striatum of the rat. One hour after the subcutaneous (s.c.) injection of saline, the DA‐D~1~ receptor antagonist SCH 23390 (0.3 mg/kg) or the DA‐D~2/3~ receptor antagonist raclopride (1.0 mg/kg), one additional s.c. injection of saline or d‐amphetamine (1.5 mg/kg) was given. The dialysates were collected at 60‐min intervals; CGRP‐like immunoreactivities (−LI) were determined by RIA. d‐Amphetamine significantly increased extracellular CGRP‐LI concentrations compared to the control animals. Administration of either SCH 23390 or raclopride did not significantly affect CGRP‐LI concentrations. Pretreatment with either SCH 23390 or raclopride abolished the stimulatory effect of d‐amphetamine on CGRP‐LI levels. The results show that d‐amphetamine administration results in an increase in extracellular concentrations of CGRP in the ventral striatum through a mechanism that appears to involve stimulation of either DA‐D~1~ or DA‐D~2/3~ receptors. The results also indicate that changes in dopaminergic neurotransmission affect CGRP outflow in the ventral striatum in a phasic but not tonic manner. J. Neurosci. Res. 64:606–611, 2001. © 2001 Wiley‐Liss, Inc.