Smagin G N, Zhou J, Harris R B, Ryan D H
Pennington Biomedical Research Center, Louisiana State University, Baton Rouge 70808, USA.
Brain Res Bull. 1997;42(6):431-4. doi: 10.1016/s0361-9230(96)00368-1.
Neuroanatomical, neurophysiological, and behavioral studies suggest that brain stem nucleus locus coeruleus (LC) plays an important role in stress response. The present study was designed to clarify, whether infusion of CRF antagonist, alpha hCRF, into LC could attenuate or block stress-induced changes in norepinephrine (NE) concentrations in microdialysates collected from the medial prefrontal cortex (PFM). Rats were implanted with a bilateral cannulae assembly aimed in the LC and a microdialysis probe (4 mm active membrane length) into the LC. Immobilization of animals significantly increased the concentration of NE in microdialysates from PFM to a maximum of 170.8 +/- 12.8% of the baseline ten minutes after the onset of stressor. Concentration of NE in dialysates remained significantly elevated for the next 40 min. Infusion of alpha hCRF into the LC significantly attenuated stress-induced increase in PFM NE concentration in samples collected at 10, 20, 30, and 50 min after the onset of immobilization. Infusion of alpha hCRF alone (no immobilization) did not change concentrations at any time during sample collection. These results are consistent with other studies and suggest that stress can facilitate NE release in the PFM through the activation of the CRF system in the brain.
神经解剖学、神经生理学及行为学研究表明，脑干蓝斑核（LC）在应激反应中发挥重要作用。本研究旨在阐明，向LC内注射促肾上腺皮质激素释放因子（CRF）拮抗剂α-hCRF，是否能够减弱或阻断应激诱导的、从前额叶内侧皮质（PFM）采集的微透析液中去甲肾上腺素（NE）浓度的变化。给大鼠双侧植入靶向LC的套管组件，并在LC内植入一个微透析探针（活性膜长度4毫米）。动物固定显著增加了应激源开始后10分钟时，PFM微透析液中NE的浓度，最高达到基线的170.8±12.8%。在接下来的40分钟内，透析液中NE的浓度仍显著升高。在固定开始后10、20、30和50分钟采集的样本中，向LC内注射α-hCRF显著减弱了应激诱导的PFM中NE浓度的增加。单独注射α-hCRF（无固定）在样本采集期间的任何时间都未改变浓度。这些结果与其他研究一致，表明应激可通过激活大脑中的CRF系统促进PFM中NE的释放。
