Effects of Morphine-like Drugs in Chicks


SEVERAL workers1–4 have used conscious chicks to study the actions of drugs. Chicks are particularly useful for drugs acting on the central nervous system, as their blood-brain barrier does not form until they are about 3 months old5,6. The effects of analgesic drugs on chicks were demonstrated at a meeting of the British Pharmacological Society7 and are described here. Analgesic action was measured by the multiple toe-pinch method8, which has been applied successfully to guinea pigs and rats. An untreated chick squeaks and shakes its foot when an artery clip is applied to one of its toes and these responses were used to test whether nociception was suppressed by drugs.

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SCHNEIDER, C. Effects of Morphine-like Drugs in Chicks. Nature 191, 607–608 (1961). https://doi.org/10.1038/191607b0

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