Ramade F, Baylé J D
C R Seances Soc Biol Fil. 1985;179(3):383-8.
It can be assumed from previous data that the stress-induced polyphasic adrenocortical response involves two phenomenons. First, direct hypothalamic afferents stimulate the adrenocorticotropic axis resulting in a rapid increase in plasma corticosterone levels up to a maximum of about 40 ng . ml-1 at 15 min. Then, a thalamic-hypothalamic loop generates the late rebounding components. Intravenous injection of muscimol (0.5 ml . kg-1) produces only slight and short duration (45 min) disturbances (piloerection; panting; corticosteronemia). Stress application, 1 hr after muscimol administration, elicits only the first peak of corticosterone with magnitude and delay similar to that in control. However, the late rebounding component is no more visible. Thus, GABA-ergic stimulation leads to a situation similar to that seen after section of neural connections between thalamic nuclei and infundibular complex. The hypothalamic-adrenocorticotropic reactivity itself is not affected whereas the function of the regulating thalamo-hypothalamic loop is markedly impaired.
从先前的数据可以推测，应激诱导的多相肾上腺皮质反应涉及两种现象。首先，下丘脑直接传入神经刺激促肾上腺皮质激素轴，导致血浆皮质酮水平迅速升高，在15分钟时最高可达约40 ng·ml-1。然后，丘脑-下丘脑环路产生后期的反弹成分。静脉注射蝇蕈醇（0.5 ml·kg-1）仅产生轻微且持续时间短（45分钟）的干扰（竖毛；喘气；皮质酮血症）。在给予蝇蕈醇1小时后施加应激，仅引发皮质酮的第一个峰值，其幅度和延迟与对照组相似。然而，后期的反弹成分不再可见。因此，γ-氨基丁酸能刺激导致的情况类似于丘脑核与漏斗复合体之间神经连接切断后所见的情况。下丘脑-促肾上腺皮质激素反应性本身不受影响，而调节性丘脑-下丘脑环路的功能则明显受损。
