鸣禽间脑听觉卵圆核壳区脑啡肽的免疫组织化学及神经联系

应用尼氏染色及脑啡肽免疫组织化学方法研究了鸣禽白腰文鸟(Lonchura striata)间脑听觉中继核--卵圆核(n. Ovoidalis Ov)中心核及其壳区(shell)的形态学特征,再应用神经示踪剂BDA (biotionylated dextran amine)对壳区的神经投射进行了研究.结果发现: (1) 脑啡肽免疫组织化学方法较尼氏染色更能区分中心核及壳区,仅Ov壳区存在脑啡肽纤维或细胞,而中心核几乎不存在;(2) Ov 壳发出纤维投向端脑听区L2b, L1 ,L3,下丘脑腹内侧核(ventromedial nucleus VMN)和下丘脑前内侧核(n. anterior medialis hypothalami AM); (3) Ov壳接受端脑古纹状体粗核(robust archistriatum RA)壳区、中脑背内侧核(mesencephalicus lateralis pars dorsalis MLd)与丘间核(n. intercollicularis ICo)界面区的投射.首次发现鸣禽卵圆核壳区同非鸣禽相似,也与下丘脑有神经投射联系,它为听觉发声引起内分泌活动及有关行为的改变提供了神经结构基础.

MET-ENKAPHALINERGIC IMMUNOREACTIVITY AND NEURAL CONNECTIVITY OF THE SHELL REGIONS OF THALAMIC NUCLEUS OVOIDALIS IN THE SONGBIRD

By use of Nissl staining and Met-enkaphalinergic immunochemistry, the auditory-relay thalamic nucleus, ovoidalis (Ov) is studied in the songbird,Lonchura striata. Then the neural projections of the shell regions of Ov are investigated by employment of a neural tract-tracer, biotinated-dextran amine (BDA). The results are as follows: (1) The Ov core and the Ov shell could be distinguished by use of Nissl staining and Met-enkaphalinergic immunochemistry. The enkaphalinergic fibers and cells are distributed in the Ov shell, but absent in the Ov core; (2) The Ov shell sends fibers to the telencephalon, the auditory Field L2b, L1 and L3, and to the hypothalamus, the ventromedial nucleus (VMN) and the nucleus anterior medialis hypothalumi (AM); (3) The Ov shell receives projections from the nucleus robust archistriatum (RA) in the telencephalon and from the interface between the nucleus intercollicularis (ICo) and the mecencepalicus lateralis pars dorsalis (MLd) in the midbrain, respectively. It is first shown at present study that the Ov shell in the songbird is also connected with the hypothalamus as that in the non-songbird reported previously. The results provide neural basis for the changes of endocrine activities caused by auditory-vocalization regulation.