| First Author | Külling P | Year | 1988 |
| Journal | Brain Res | Volume | 450 |
| Issue | 1-2 | Pages | 237-46 |
| PubMed ID | 3401713 | Mgi Jnum | J:26025 |
| Mgi Id | MGI:73751 | Doi | 10.1016/0006-8993(88)91563-6 |
| Citation | Kulling P, et al. (1988) Social conflict-induced changes in nociception and beta-endorphin-like immunoreactivity in pituitary and discrete brain areas of C57BL/6 and DBA/2 mice. Brain Res 450(1-2):237-46 |
| abstractText | The present study characterizes the time course of social conflict analgesia and its reversibility by opioid antagonist drugs in the C57BL/6 and DBA/2 inbred strains of mice and examines the relationship between alterations in brain and pituitary levels of beta-endorphin-like immunoreactivity (beta-ELIR) and the antinociception elicited by social stress. Data revealed statistically significant strain differences in regard to beta-ELIR in control animals. The pituitary content of beta-ELIR was higher in DBA/2, while the values in the periaqueductal grey (PAG) and in the amygdala were higher in C57BL/6 mice. No interstrain differences were found in the hypothalamus. Exposure to 50 attack bites resulted in a 6-fold higher analgesia in DBA/2 mice and in a strain-independent fall of beta-ELIR in pituitary (approximately 27%) and PAG (23%). PAG but not pituitary beta-ELIR levels in C57BL/6 mice correlated positively with the increase in tail-flick latency after attack. Mere confrontation with a non-aggressive opponent failed to induce analgesia and was associated in C57BL/6 mice with a significant reduction in the beta-ELIR content of both the pituitary and the PAG. The data are discussed in terms of genotype-dependent sensitivity of the beta-endorphin system to stress and its relation to analgesia. |
