Jacob N, Vuillez P, Lakdhar-Ghazal N, Pévet P
UMR-CNRS 7518, 'Neurobiologie des fonctions rythmiques et saisonnières' Université Louis Pasteur, 12 rue de l'Université, 67000, Strasbourg, France.
Brain Res. 1999 May 15;828(1-2):83-90. doi: 10.1016/s0006-8993(99)01324-4.
The circadian clock located in the suprachiasmatic nuclei (SCN) is influenced by the photoperiod. After the transfer from a long (LP 14:10) to a short photoperiod (SP 10:14), the adjustment of the light sensitivity of the SCN, in terms of Fos expression, takes 25 nights. To examine the contribution of the thalamic intergeniculate leaflet (IGL) and its NPY-immunoreactive projection in the extension of the duration of the photosensitive phase of the SCN, male Syrian hamsters received electrolytic lesions of the IGL. We showed a lower number of Fos-ir cells in the SCN of IGLx hamsters following a light pulse applied 13 h after dark onset, 25 nights after the transfer from LP to SP compared to sham operated hamsters. The present study shows that the integrity of the IGL is necessary to have a complete integration of photoperiodic changes by the SCN. This demonstrates the involvement of the IGL in the integration of photoperiodic information by the SCN.
位于视交叉上核（SCN）的生物钟受光周期影响。从长光周期（LP 14:10）转变为短光周期（SP 10:14）后，就Fos表达而言，SCN光敏感性的调整需要25个夜晚。为了研究丘脑间膝小叶（IGL）及其NPY免疫反应性投射在延长SCN光敏期持续时间中的作用，雄性叙利亚仓鼠接受了IGL的电解损伤。我们发现，与假手术仓鼠相比，在从LP转变为SP 25个夜晚后，于黑暗开始13小时后施加光脉冲，IGLx仓鼠的SCN中Fos免疫反应性细胞数量较少。本研究表明，IGL的完整性是SCN完整整合光周期变化所必需的。这证明了IGL参与SCN对光周期信息的整合。
