The effects of ethylketocyclazocine (EKC), Mr 2266 and naltrexone on the stereotyped behaviors induced by an intraperitoneal injection of phencyclidine (PCP) were examined. PCP-induced turning, backpedalling, head weaving and sniffing were antagonized by pretreatment with EKC (0.25-4.0 mg/kg). While pretreatment with Mr 2266 (2.5 mg/kg), a χ selective antagonist, and naltrexone (10 mg/kg), a μ selective antagonist, failed to affect the PCP-induced stereotypy, Mr 2266 antagonized the suppressing effect of EKC on PCP-induced stereotypy. Taken into consideration, this suggests that χ opioid agonists such as EKC antagonize PCP-induced stereotyped behaviors through a χ opioid mechanism, and that the μ opioid receptor may not play an important role in the PCP-induced stereotypy in rats.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Clinical Neurology
- Developmental Biology