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A Conditioned Place Preference Protocol for Measuring Incubation of Craving in Rats
Published on: November 6, 2018
Morphine induces conditioned place preference behavior in histidine decarboxylase knockout mice
Ying-xia Gong1, Wei-ping Zhang, Wen-ting Shou
1Department of Pharmacology, Yunyang Medical College, Shiyan, China.
Neuroscience Letters
|November 3, 2009
Summary
Endogenous histamine inhibits the development of morphine reward-seeking behavior but not its extinction. Histamine deficiency in mice enhanced morphine reward and reduced withdrawal symptoms, suggesting a role in modulating dopamine.
Area of Science:
- Neuroscience
- Pharmacology
- Genetics
Background:
- Histamine is known to inhibit morphine-induced reward-seeking behavior.
- Endogenous histamine's role in morphine reward and withdrawal remains unclear.
Purpose of the Study:
- To investigate the role of endogenous histamine in morphine-induced reward-seeking behavior.
- To examine the effect of histamine deficiency on morphine reward and withdrawal using genetically modified mice.
Main Methods:
- Utilized histidine decarboxylase gene knockout (HDC-KO) mice and wild-type (WT) littermates.
- Assessed morphine-induced conditioned place preference (CPP) and its extinction.
- Measured dopamine levels in the ventral tegmental area (VTA) and nucleus accumbens (NAc).
- Evaluated naloxone-precipitated withdrawal jumping behavior.
Main Results:
- HDC-KO mice exhibited stronger morphine-induced CPP compared to WT mice.
- Morphine increased dopamine levels in the VTA and NAc, with a more pronounced effect in HDC-KO mice.
- CPP extinction was similar in both genotypes.
- HDC-KO mice showed significantly reduced naloxone-precipitated withdrawal jumping.
Conclusions:
- Endogenous histamine inhibits the development of morphine-induced CPP, but not its extinction.
- Histamine deficiency enhances morphine reward and reduces withdrawal severity, likely via modulation of dopaminergic activity.
- These findings highlight histamine as a potential target for managing opioid reward and withdrawal.
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