EVIDENCE FOR A TACHYKININ CHOLINERGIC MEDIATION OF D-1 AGONIST-INDUCED TURNING IN MICE

The turning behavior induced by the intrastriatal injection of the D-1 agonist (+)SKF 38393 was blocked by the two selective non-peptide tac hykinin NK1(SR 140333)(ID50 = 0.09 mg/kg ip) and NK2(SR 48968)(ID50 = 1.4 mg/kg ip) receptor antagonists and by atropine(ID50 = 2.6 mg/kg ip ). In addition, the turning induced by the intrastriatal injection of NK1(septide) and NK2([Nle(10)]NKA(4-10)) receptor agonists were antago nized by atropine (ID50s = 1.1 mg/kg ip and 0.78 mg/kg ip, respectivel y). This behavioral study shows that tachykinin receptor activation is an essential component of DA-D-1/Ach interaction in the mouse striatu m and confirms the previously suggested functional importance of NK2 r eceptors in the central nervous system.