Shimokawa Kayo, Numata Hideharu, Shiga Sakiko
Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2008 Aug;194(8):751-62. doi: 10.1007/s00359-008-0346-y. Epub 2008 Jun 11.
The morphology and functions of the brain neurons projecting to the retrocerebral complex were examined in terms of photoperiodic control of adult diapause in the bean bug, Riptortus pedestris. Backfills through the nervi corporis cardiaci stained 15-20 pairs of somata in the pars intercerebralis (PI) with contralateral axons, and 14-24 pairs in the pars lateralis (PL) with ipsilateral axons to the nervi corporis cardiaci. In the PL, two clusters of somata, PL-d and PL-v, were found. Forwardfills showed neurons in the PI terminated in the aorta, and those in the PL at the corpus cardiacum, corpus allatum, and aorta. Removal of the PI did not cause effects on diapause incidence both under short-day (12 h:12 h, light:dark) and long-day conditions (16 h:8 h, light:dark) at 25 degrees C. Under short-day conditions, diapause incidence was significantly lower than the controls after removal of the PL. Either removal of PL-d or PL-v did not reduce diapause incidence. It decreased only when both the PL-d and PL-v were ablated. The PI is not indispensable for diapause in R. pedestris, and both PL-d and PL-v neurons are suggested to be involved in photoperiodic inhibition of ovarian development.
根据豆蝽（Riptortus pedestris）成虫滞育的光周期控制，研究了投射到脑后复合体的脑神经元的形态和功能。通过心侧体神经进行逆向填充，在脑间部（PI）中标记了15 - 20对带有对侧轴突的胞体，在外侧部（PL）中标记了14 - 24对带有同侧轴突至心侧体神经的胞体。在PL中，发现了两簇胞体，即PL - d和PL - v。顺向填充显示，PI中的神经元终止于主动脉，PL中的神经元终止于心侧体、咽侧体和主动脉。在25摄氏度下，短日（12小时光照：12小时黑暗）和长日（16小时光照：8小时黑暗）条件下，去除PI对滞育发生率均无影响。在短日条件下，去除PL后滞育发生率显著低于对照组。单独去除PL - d或PL - v均未降低滞育发生率。只有当PL - d和PL - v都被切除时，滞育发生率才会降低。PI对于豆蝽的滞育并非不可或缺，并且PL - d和PL - v神经元均被认为参与了对卵巢发育的光周期抑制。
