Enhanced oral activity responses to intrastriatal SKF 38393 and m-CPP are attenuated by intrastriatal mianserin in neonatal 6-OHDA-lesioned rats

Psychopharmacology (Berl). 1995 Jun;119(4):466-73. doi: 10.1007/BF02245863.


Enhanced oral activity is induced in neonatal 6-hydroxydopamine- (6-OHDA-) lesioned rats by systemic administration of the dopamine (DA) D1 receptor agonist SKF 38393 and serotonin (5-HT) 5-HT2A,2C agonist m-chlorophenylpiperazine (m-CPP). The DA D1 receptor antagonist SCH 23390 effectively attenuates the effect of SKF 38393 but not m-CPP. The 5-HT2 antagonist mianserin attenuates the effects of both m-CPP and SKF 38393, suggesting that DA agonist effects are mediated by 5-HT neurochemical systems. To test whether DA and 5-HT agonist effects and interactions might occur within the neostriatum, rats were implanted with permanent injection cannulae, with tips in the ventral striatum. One group of rats was lesioned at 3 days after birth with 6-OHDA HBr (100 micrograms salt form, in each lateral ventricle; desipramine HCl pretreatment, 20 mg/kg IP, base form, 1 h), while controls received the vehicle in place of 6-OHDA. Cannulae were implanted when rats weighed 200-250 g. During a 1-h observation session SKF 38393 (5 nmol per side) produced 74.3 +/- 19.2 oral movements in intact rats and 310.7 +/- 97.0 oral movements in 6-OHDA-lesioned rats. m-CPP (10 nmol per side) produced 72.6 +/- 15.1 and 274.5 +/- 65.0 oral movements in these respective groups. These responses were several-fold greater than the 25.3 +/- 7.3 and 41.8 +/- 9.5 oral movements in the same groups after saline (0.5 microliter per side) (P < 0.05). Mianserin (6 nmol per side) alone had no effect on oral activity but attenuated responses to both SKF 38393 and m-CPP in intact and 6-OHDA-lesioned rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / pharmacology*
  • Animals
  • Corpus Striatum / drug effects*
  • Female
  • Mianserin / pharmacology*
  • Motor Activity / drug effects*
  • Mouth / drug effects*
  • Oxidopamine / pharmacology
  • Piperazines / pharmacology*
  • Rats
  • Rats, Inbred Strains
  • Serotonin Receptor Agonists / pharmacology*


  • Piperazines
  • Serotonin Receptor Agonists
  • Mianserin
  • 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine
  • Oxidopamine
  • 1-(3-chlorophenyl)piperazine