Bordey Angelique
Departments of Neurosurgery, and Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, FMB 422, New Haven, CT 06520-8082, USA.
Brain Res Rev. 2007 Jan;53(1):124-34. doi: 10.1016/j.brainresrev.2006.07.004. Epub 2006 Sep 1.
The discovery and description of complex GABAergic networks in adult neurogenic zones suggest the intriguing possibility of information transfer from neuronal activity to immature cells. New questions also emerge regarding the mode of GABAergic signaling and the temporal pattern of receptor activation. Non-synaptic (paracrine) signaling communicates information on population size to control the proliferation and migration of progenitor cells in the subventricular zone. How this signaling relates to olfactory bulb network activity, however, remains largely unknown. This review argues that paracrine signaling precedes and then co-exists with synaptic GABAergic signaling, which provides the timing and instruction for cells to properly differentiate and synaptically integrate into an existing network. The evidence examined in this review indicates that the commonly cited mechanism of GABA's action (i.e., depolarization leading to voltage-gated calcium channel activation and calcium entry) needs to be re-examined in the context of the unique cellular properties and organization of the adult neurogenic regions.
在成体神经发生区发现并描述复杂的γ-氨基丁酸能（GABAergic）网络，提示了从神经元活动向未成熟细胞进行信息传递的有趣可能性。关于GABA能信号传导模式以及受体激活的时间模式，也出现了新的问题。非突触（旁分泌）信号传导传递有关群体大小的信息，以控制脑室下区祖细胞的增殖和迁移。然而，这种信号传导与嗅球网络活动之间的关系在很大程度上仍不清楚。本综述认为，旁分泌信号传导先于突触GABA能信号传导并与之共存，后者为细胞正确分化并通过突触整合到现有网络中提供时机和指令。本综述所审视的证据表明，在成体神经发生区域独特的细胞特性和组织结构背景下，通常所提及的GABA作用机制（即去极化导致电压门控钙通道激活及钙内流）需要重新审视。
