Modulation of stress-induced ACTH release by corticotropin-releasing factor, catecholamines and vasopressin

The stress-induced release of ACTH is believed to involve the activation of several humoral and neural pathways, including corticotropin-releasing factor (CRF), catecholamines and vasopressin. The essential role of CRF was supported by our observation that immunoneutralization of this releasing factor significantly lowers plasma ACTH levels of ether-stressed rats. However, the presence of a small but measurable residual ACTH secretion suggested the possible involvement of factors other than CRF in the stress response. We report here that pretreatment with a vasopressin antagonist decreases the plasma ACTH levels of ether-stressed rats in later (10-20 min), but not earlier (0-10 min), phases of ether stress. The ganglionic blocker chlorisondamine, inhibits ACTH release during both phases of the response to ether by 40-60% when used alone, and by 100% when administered with anti-CRF antibody. These results support a role of CRF, catecholamines and vasopressin in mediating ACTH release by ether stress.     

Intrinsic functional architecture in the anaesthetized monkey brain

The traditional approach to studying brain function is to measure physiological responses to controlled sensory, motor and cognitive paradigms. However, most of the brain's energy consumption is devoted to ongoing metabolic activity not clearly associated with any particular stimulus or behaviour. Functional magnetic resonance imaging studies in humans aimed at understanding this ongoing activity have shown that spontaneous fluctuations of the blood-oxygen-level-dependent signal occur continuously in the resting state. In humans, these fluctuations are temporally coherent within widely distributed cortical systems that recapitulate the functional architecture of responses evoked by experimentally administered tasks. Here, we show that the same phenomenon is present in anaesthetized monkeys even at anaesthetic levels known to induce profound loss of consciousness. We specifically demonstrate coherent spontaneous fluctuations within three well known systems (oculomotor, somatomotor and visual) and the 'default' system, a set of brain regions thought by some to support uniquely human capabilities. Our results indicate that coherent system fluctuations probably reflect an evolutionarily conserved aspect of brain functional organization that transcends levels of consciousness.     

四川马海毛的氨基酸分析

用日立835－50型氨基酸分析仪对四川马海毛的氨基酸进行了测试分析。结果表明：四川马海毛与另几种动物纤维所包含的氨基酸种类基本一致，且各氨基酸含量相近；四川马海毛的氨基酸总一为76．19％，比张忠英和薛纪莹老师报道的陕北马海毛低22．02个百分点；高含硫氨基酸总含量为16．71％，低硫的为31．12％，与陕北马洗毛纤维是同样规律；胱氨酸含量为6．32％；四川马海毛氨的含量为0．76％，低于其它几种对比纤维的氨含量。