生长锥钙电流的调节由一种对百日咳毒素（PTX）敏感的G蛋白介导。

Modulation of growth cone calcium current is mediated by a PTX-sensitive G protein.

作者信息

Man-Son-Hing H, Haydon P G

机构信息

Department of Zoology and Genetics, Iowa State University, Ames 50011.

出版信息

Neurosci Lett. 1992 Mar 16;137(1):133-6. doi: 10.1016/0304-3940(92)90315-x.

DOI:10.1016/0304-3940(92)90315-x

PMID:1320749

Abstract

Growth cones of isolated neurons B5 of Helisoma were voltage clamped in the whole-cell configuration. Depolarization of growth cones to -20 mV or greater activated a high-voltage-activated (HVA) calcium current. Addition of the neuropeptide FMRFamide (1 microM), which causes a presynaptic inhibition of synaptic transmission, reversibly reduced the calcium current magnitude. This inhibitory effect is mediated by a pertussis toxin (PTX)-sensitive G protein. Dialysis with the non-hydrolyzable GTP analogs GTP gamma S and Gpp(NH)p caused FMRFamide's effect to become irreversible. Dialysis with GDP beta S or preincubation with PTX prevented FMRFamide from reducing the calcium current. Thus, one role of growth cone G proteins is to modulate ion channels in growth cone membrane which in turn may control growth cone motility.

摘要

将福寿螺分离出的神经元B5的生长锥以全细胞模式进行电压钳制。将生长锥去极化至-20 mV或更高会激活一种高电压激活（HVA）钙电流。添加神经肽FMRF酰胺（1微摩尔），其会引起突触前对突触传递的抑制，可使钙电流幅度可逆性降低。这种抑制作用由百日咳毒素（PTX）敏感的G蛋白介导。用不可水解的GTP类似物GTPγS和Gpp(NH)p进行透析会使FMRF酰胺的作用变得不可逆。用GDPβS进行透析或用PTX预孵育可防止FMRF酰胺降低钙电流。因此，生长锥G蛋白的一个作用是调节生长锥膜中的离子通道，进而可能控制生长锥的运动性。