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Morphine conditioned taste aversion reversed by periaqueductal gray lesions
Pharmacology, Biochemistry, and Behavior
|October 1, 1981
Summary
The periaqueductal gray (PAG) is crucial for morphine-induced conditioned taste aversion (CTA). Lesioning the PAG reversed morphine CTA but not aversions caused by other drugs, suggesting a specific role for the PAG in morphine aversion.
Area of Science:
- Neuroscience
- Behavioral Pharmacology
Background:
- Conditioned taste aversion (CTA) is a learned aversion to a flavor associated with nausea.
- The periaqueductal gray (PAG) is implicated in various behavioral processes, including pain and aversion.
Purpose of the Study:
- To investigate the role of the periaqueductal gray (PAG) in the development of morphine-conditioned taste aversion (CTA).
Main Methods:
- Male Wistar rats were presented with a novel saccharin solution.
- Animals received intraperitoneal injections of morphine, lithium, ethanol, or fenfluramine.
- PAG lesions were performed in a subset of animals.
- CTA was measured by the amount of saccharin consumed during a subsequent presentation.
Main Results:
- A PAG lesion significantly reversed the conditioned taste aversion (CTA) induced by morphine.
- PAG lesions did not affect CTAs produced by lithium, ethanol, or fenfluramine.
- These findings indicate a specific involvement of the PAG in morphine-mediated CTA.
Conclusions:
- The periaqueductal gray (PAG) plays a significant role in mediating morphine-induced conditioned taste aversion (CTA).
- The PAG's involvement appears specific to morphine CTA, differentiating it from aversions caused by other drugs.
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