Significant Reduction In Reaction Time Research Articles

Immediate effects of chlorpromazine and perphenazine following neuroleptic washout on word association of schizophrenic patients

Reaction time and idiosyncrasy of word associations were examined in 30 schizophrenic patients, 2 h after administering a single dose of chlorpromazine, perphenazine or placebo. These patients were in the acute phase of their illness following 72 h cessation of oral neuroleptic treatment administered for 1–2 weeks. There was a statistically significant reduction in reaction times after administering perphenazine as compared to the placebo. Chlorpromazine showed some reduction in reaction times that was not statistically significant. Further study is needed to examine the relationship between such changes and other parameters, such as the patients' symptomatology and their social competence. Since many schizophrenic patients exhibit low or partial compliance, including patterns of intermittent taking of medication with a few days cessation, studies using such a model of a single dose of neuroleptic following several days withdrawal, may have clinical relevance. Another finding was a correlation between reaction time and the number of uncommon word associations produced. This correlation was beyond drug effect. Further study is needed to find out if such a correlation characterizes schizophrenic patients only.

The effects of maternally-administered morphine on rat foetal development and resultant tolerance to the analgesic effect of morphine.

Groups of 6–9 pregnant (sperm = Day 1) Sprague‐Dawley (Simonsen) rats were injected with morphine sulphate, 20 mg/kg subcutaneously, on gestational days 2–5, 7–9 or 11–13. Pups delivered by Caesarian section on gestational day 22 were essentially free of any observable teratogenic changes including bone defects. However, offspring of morphine‐treated rats (20 mg/kg/day subcutaneously on gestational days 17, 18, 19 and 20) which were allowed to litter normally exhibited on day 12–13 a significantly (P < 0.05) decreased response to a nocioceptive (55° surface) stimulus 30 min. following an injection of morphine sulphate 0.45 mg/kg subcutaneously (offspring of morphine‐treated mothers, 16.8 sec. ± 2.3 S.E.M. versus control offspring, 25.2 sec. ± 1.7 S.E.M.). On days 21–22 of age larger doses of morphine were required to elicit an analgesic response in the young. Following an injection of morphine sulphate, 10 mg/kg subcutaneously, the maternal animals also showed significant reduction in reaction time 30 minutes later (treated, 7.6 sec. ± 0.6 S.E.M. versus control, 16.1 sec. ± 0.6 S.E.M.) and 60 minutes later (treated, 7.5 sec. ± 0.9 S.E.M. versus control, 20.8 sec. ± 2.9 S.E.M.) as compared to paired waterinjected control pregnant animals.