REPETITIVE EXPOSURE TO THE HOT-PLATE TEST PRODUCES STRESS-INDUCED ANALGESIA AND ALTERS BETA-ENDORPHIN NEURONAL TRANSMISSION WITHIN THE PERIAQUEDUCTAL GRAY OF THE RAT
Aa. Hawranko et al., REPETITIVE EXPOSURE TO THE HOT-PLATE TEST PRODUCES STRESS-INDUCED ANALGESIA AND ALTERS BETA-ENDORPHIN NEURONAL TRANSMISSION WITHIN THE PERIAQUEDUCTAL GRAY OF THE RAT, Brain research, 667(2), 1994, pp. 283-286
Repetitive exposure of rats to a hot plate induced a novel non-opioid
form of stress induced analgesia. The exposure caused a persistent 1.5
-2 s increase in tail flick latency which was not attenuated by system
ic naltrexone, but was completely inhibited by systemic MK-801. Concom
itantly, alterations occurred in the ability to pharmacologically dist
inguish multiple beta-endorphin receptors in the periaqueductal gray.
Thus, in response to different forms of stress, different pathways may
be activated by beta-endorphin, resulting in stress induced analgesia
s with varied pharmacological characteristics (e.g., opioid and non-op
ioid).