Ramade F, Bouillé C, Baylé J D
Neuroendocrinology. 1980 May;30(5):323-8. doi: 10.1159/000123022.
Thalamic and intact pigeons were equipped with a chronic arterial catheter and with a miniature electronic device for hypothalamic telestimulation. Chronic catheterization allowed for repetitive blood sampling in freely moving birds subjected to either systemic (ether inhalation) or neurogenic (electrical foot shocks) stress and to electrical stimulation of the hypothalamic corticotropic area. Corticosterone levels were determined by protein binding assay at 2-, then 5- and 10-min intervals, for 100 min. Basal and experimentally modified plasma corticosterone concentrations were not different in thalamic and intact pigeons. Corticosterone profile exhibited episodic increase including three peaks at 12, 35 and 60 min after stress application. Only the first peak of plasma corticosterone appeared after hypothalamic stimulation. It is suggested that extrahypothalamic neuronal networks are responsible for the long-lasting repetitive adrenocorticotropic response to stress, which are not involved in the single response to hypothalamic stimulation itself. Furthermore, such extrahypothalamic neuronal networks shoudl be located at the diencephalic or rhombencephalic level since hemispherectomized pigeons exhibited the same profile of stress-induced episodic hypercorticosteronemia as seen in intact birds.
给丘脑损毁和未损毁的鸽子安装了一根慢性动脉导管以及一个用于下丘脑远距刺激的微型电子装置。慢性插管使得在自由活动的鸟类中能够重复采集血液样本，这些鸟类会受到全身性（乙醚吸入）或神经性（足部电击）应激，以及下丘脑促肾上腺皮质激素区的电刺激。通过蛋白质结合分析法，每隔2分钟，然后是5分钟和10分钟，持续100分钟来测定皮质酮水平。丘脑损毁和未损毁的鸽子的基础血浆皮质酮浓度以及经实验改变后的浓度并无差异。皮质酮水平呈现出间歇性升高，在施加应激后12分钟、35分钟和60分钟出现三个峰值。只有血浆皮质酮的第一个峰值出现在下丘脑刺激之后。这表明下丘脑外的神经网络负责对应激产生持久的重复性促肾上腺皮质反应，而这些反应并不参与对下丘脑刺激本身的单次反应。此外，由于半球切除的鸽子表现出与未损毁鸟类相同的应激诱导间歇性高皮质酮血症特征，所以这种下丘脑外的神经网络应该位于间脑或后脑水平。
