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B J Sahakian

Publications and source records attributed to B J Sahakian.

10 recordsLinked to original sources
PubMed1979

Environmentally induced differences in susceptibility of rats to CNS stimulants and CNS depressants: evidence against a unitary explanation.

It has been suggested that socially isolated rats are more aroused then rats raised in social groups. This hypothesis was tested by examining amphetamine-induced activity and stereotypy in social and isolated rats of both sexes in both the active and inactive phases of their diurnal activity cycle. In socially raised rats it was possible to produce behavioural profiles similar to those of isolated rats by increasing the arousal level of the social rat. However, the complex interaction of housing conditions, diurnal variation and gender with drug dose suggests that one intervening variable such as arousal is too simplistic an explanation. In subsequent experiments, stereotypy was enhanced by a familiar environment, and there was a clear dissociation between the effects of CNS stimulants and CNS depressants. The increased susceptibility of isolates to CNS stimulants depends on social isolation for a short period before 45 days of age; the decreased susceptibility of isolates to CNS depressants may be produced by isolation at any age. We conclude that there is no evidence that isolated rats are hyperaroused.

Animals↗
PubMed1977

Effects of chlordiazepoxide on tail pinch-induced eating in rats.

The effects of 5, 10, and 20 mg/kg chlordiazepoxide on tail pinch (TP)-induced behavior were investigated. Five mg/kg enhanced TP-induced eating in terms of both latency and duration. Twenty mg/kg had decremental effects. All doses of the drug reduced the incidence of clip-directed behavior, but increased locomotor activity during the TP trials in a dose-dependent manner. On control trials, the drug increased locomotor activity at the low dose and eating at the high dose. The results are examined in terms of the various behavioral actions of the minor tranquilizers. The implications for the behavioral and neuropharmacological mechanisms underlying TP-induced and other forms of stimulus-bound behavior are discussed.

Animals↗
PubMed1975

The effects of psychomotor stimulants on stereotypy and locomotor activity in socially-deprived and control rats.

Using measures of locomotor activity and stereotypy, dose-response curves to several psychomotor stimulant drugs were obtained on rats reared in deprived or normal environments. At both 0.5 and 1.5 mg/kg d-amphetamine, the deprived rats exhibited more intense stereotyped behavior than the control rats. At 5.0 mg/kg, both groups showed maximum response. However, there was no significant difference between the two groups in locomotor response. A similar pattern of results was found for pipradrol, cocaine, and apomorphine. The findings show that different social and environmental experience can modify the response to dopaminergic stimulating agents. The results also suggest that stereotyped behavior should not be considered on the same continuum as locomotor activity. These two behaviors may be mediated by different mechanisms.

Amphetamine↗
PubMedDate not supplied

Are the effects of psychomotor stimulant drugs on hyperactive children really paradoxical?

The improved "attention" exhibited by hyperactive children treated with amphetamine-like compounds is postulated to be related to a normal action of these drugs in producing stereotyped behavior. Such activity can be conceptualised as an increased "focusing" of attention, which would be expected to aid performance in tasks involving sustained concentration of attention, but impair performance on tasks involving reversals in cognitive strategy. These behavioural actions of the drugs can be linked to the functioning of central dopaminergic mechanisms.

Amphetamines↗