Luckman S M, Dye S, Cox H J
Department of Neurobiology, Babraham Institute, Cambridge, U.K.
Neuroscience. 1996 Jul;73(2):473-85. doi: 10.1016/0306-4522(96)00076-0.
In situ hybridization was used to measure the expression of members of the Fos/Jun family of immediate-early genes in hypothalamic neurons in vivo following defined stimuli that utilize different afferent pathways. Only c-jun messenger RNA was expressed in the hypothalamic supraoptic and paraventricular nuclei of control animals. Intravenous infusions of sodium chloride solutions of different tonicity produced a range of plasma osmolalities within physiological limits. While the induction of c-fos and jun B messenger RNAs followed the stimulus intensity, the expression of c-jun was repressed at low levels of stimulation. A higher level of osmotic stimulation was able to co-induce c-jun with the c-fos, jun B and fos B genes, suggesting that other signalling pathways may then be activated. Parturition or systemic administration of cholecystokinin, that activate supraoptic and paraventricular neurons via ascending afferent pathways from the brainstem, both induced c-fos, but not the other genes, in the magnocellular nuclei. Use of double in situ hybridization confirmed that, unlike with osmotic stimulation, induction of c-fos only occurred in oxytocin neurons. These two stimuli did not cause a concomitant repression of c-jun messenger RNA expression in magnocellular oxytocin neurons. These patterns of induction provide evidence for the differential regulation of members of this family of genes in a physiological context.
原位杂交用于测量在利用不同传入通路的特定刺激后，体内下丘脑神经元中即早基因Fos/Jun家族成员的表达。在对照动物的下丘脑视上核和室旁核中，仅表达c-jun信使核糖核酸。静脉输注不同张力的氯化钠溶液可在生理范围内产生一系列血浆渗透压。虽然c-fos和jun B信使核糖核酸的诱导遵循刺激强度，但在低水平刺激下c-jun的表达受到抑制。更高水平的渗透压刺激能够与c-fos、jun B和fos B基因共同诱导c-jun，这表明其他信号通路可能随后被激活。分娩或全身给予胆囊收缩素，通过来自脑干的上行传入通路激活视上核和室旁核神经元，两者均在大细胞神经核中诱导c-fos，但不诱导其他基因。双重原位杂交的结果证实，与渗透压刺激不同，c-fos的诱导仅发生在催产素神经元中。这两种刺激并未导致大细胞催产素神经元中c-jun信使核糖核酸表达的伴随性抑制。这些诱导模式为该基因家族成员在生理背景下的差异调节提供了证据。
