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J E Olley

Publications and source records attributed to J E Olley.

32 records · Page 2Linked to original sources

Involvement of the median raphe nucleus in antinociception induced by morphine, buprenorphine and tilidine in the rat.

1 Antinociception induced by three analgesics with differing profiles of activity, morphine, buprenorphine and tilidine, have been evaluated in the hot plate and paw pressure tests after administration by the subcutaneous route and directly into the median raphe nucleus in the conscious rat. 2 Behavioural and neurological effects of the three analgesics were also assessed. 3 The typical profiles of antinociceptive activity induced by the three analgesics were qualitatively similar after either route of administration. Morphine induced naloxone-sensitive dose-dependent effects in both tests. Buprenorphine showed naloxone-sensitive effects with a bell-shaped dose-response curve in the thermal test but dose-dependent activity in the pressure test. Tilidine induced naloxone-sensitive dose-dependent effects in the thermal test but demonstrated naloxone-insensitive activity in the paw pressure test. 4 The behavioural and neurological effects of the analgesics in the dose range used would not have affected the animals' ability to respond to the nociceptive stimuli. 5 The results suggest that the median raphe could participate in drug-induced antinociception. The mechanisms by which this might occur are discussed.

Analgesics↗

Dissociation of the anti-punishment activities of chlordiazepoxide and atropine using two heterogeneous passive avoidance tasks.

The effects of chlordiazepoxide and atropine on the acquisition of passive avoidance learning in rats were compared in two superficially similar but theoretically distinct forms of the step down task in an attempt to dissociate behaviourally the disinhibiting effects of these two classes of drug. In a discrete trial procedure both chlordiazepoxide and atropine significantly retarded acquisition; on retention testing under saline treatment alone, the initial chlordiazepoxide group showed no change in behaviour while the initial atropine group showed a facilitation. In a continuous trial procedure, however, atropine but not chlordiazepoxide produced an increase in the total number of step downs; despite this, these groups showed acquisition at similar rates, though learning was not shown on retention testing under saline alone. These results enabled the two classes of drug to be distinguished. The nature of the heterogeneity between the two test paradigms is discussed, and results interpreted in terms of possible differential drug effects on punishment and escape components of the tasks.

Animals↗