Effects of β-casomorphin-7 on different types of learning in white rats
The heptapeptide β-casomorphin-7, a casein fragment of cow's milk, accelerated the learning of a food-procuring habit in a T-maze by rats injected with this heptapeptide in a dose of 1 or 5 mg/kg body weight 5 min before the start of each learning session. This effect was blocked by pretreating rats with naloxone. On the other hand, β-casomorphin-7 in the indicated doses delayed learning of the active avoidance response involving the use of a painful reinforcing stimulus. The results of this study indicate that β-casomorphin-7 attenuates defense reactions by shifting the total balance of motivations toward food-procuring behavior.
Key Wordslearning β-casomorphin-7 and analogs opioids naloxone
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