Ballesteros Jose M, VAN DER List Deborah A, Chalupa Leo M
Section of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California, Davis CA 95616, USA.
Thalamus Relat Syst. 2005;3(2):157-163. doi: 10.1017/S1472928807000167.
We compared the developmental periods in the mouse when projections from the two eyes become segregated in the dorsal lateral geniculate nucleus with the time when this nucleus becomes innervated by cholinergic fibers from the brainstem. Changes in labeling patterns of different tracers injected into each eye revealed that segregation of retinogeniculate inputs commences at postnatal day five (P5) and is largely complete by P8. Immunocytochemical staining showed that cholinergic neurons are present in the parabrachial region of the brain stem on the day of birth. However, cholinergic fibers are not evident in the geniculate until P5, and these are sparse at this age, increasing in density to form well-defined clusters by P12. These results indicate that segregation of eye-specific projections during normal development is unlikely to be regulated by cholinergic inputs from the brainstem.
我们比较了小鼠双眼投射在背侧外侧膝状核中分离的发育时期，以及该核被来自脑干的胆碱能纤维支配的时间。注入每只眼睛的不同示踪剂标记模式的变化表明，视网膜膝状体输入的分离在出生后第5天（P5）开始，并在P8时基本完成。免疫细胞化学染色显示，出生当天脑干臂旁区域存在胆碱能神经元。然而，直到P5，膝状核中才出现明显的胆碱能纤维，且在这个年龄段数量稀少，到P12时密度增加，形成界限分明的簇。这些结果表明，正常发育过程中眼特异性投射的分离不太可能受脑干胆碱能输入的调节。
