Phencyclidine-induced stereotype in rats: effects of methadone, apomorphine, and naloxone.
K Verebey, M J Kogan, S J Mulè
Psychopharmacology 1981 DOI: 10.1007/bf00433500 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Preclinical animal study Peer reviewed |
|---|---|
| Population | Male Wistar rats |
| Interventions | Phencyclidine (PCP) Methadone Apomorphine Naloxone |
| Dose | Methadone 0.5 mg/kg; naloxone up to 20 mg/kg |
| Key points | Methadone (0.5 mg/kg) and low-dose apomorphine attenuated PCP-induced stereotypy in rats without affecting PCP-induced hyperactivity; naloxone given afterward restored the stereotypy. The authors propose that this antagonism may be mediated by opiate receptors and suggest opiates might be effective in treating PCP-induced and functional psychoses. |
Abstract
Phencyclidine (PCP) given to male Wistar rats produced hyperactivity and various stereotypic motor behaviors. Methadone, apomorphine, and naloxone were tested for their effects on PCP-induced stereotypy. Methadone (0.5 mg/kg) had no effect on the hyperactivity produced by PCP, but significantly attenuated PCP-induced stereotypy when given both before and after PCP. Low doses of apomorphine were equally effective as methadone in attenuating PCP-induced stereotypy. However, when naloxone was given after methadone or apomorphine to PCP-treated rats, the full PCP-induced stereotypy was again observed. Naloxone pretreatment on doses up to 20 mg/kg was not effective in antagonizing PCP-induced behavioral effects. Methadone and apomorphine antagonism of PCP-induced stereotypy may be mediated by opiate receptors. The results of this study and observations from human studies collectively suggest the possible effectiveness of opiates in treating PCP-induced and functional psychoses.
Citations in the library
Cited by 4
- Phencyclidine in the social interaction test: an animal model of schizophrenia with face and predictive validity. Reviews in the Neurosciences 1999
- Effects of diazepam, citalopram, methadone and naloxone on PCP-induced stereotyped behaviour and social isolation in the rat social interaction test. Neuroscience & Biobehavioral Reviews 1998
- The behavioral and neurochemical effects of phencyclidine in humans and animals: some implications for modeling psychosis. Behavioural Brain Research 1996
- Automation of the social interaction test by a video-tracking system: behavioural effects of repeated phencyclidine treatment. Journal of Neuroscience Methods July 1995