Federmeier Kara D, Kleim Jeffrey A, Greenough William T
Department of Psychology, University of Illinois Urbana-Champaign, Urbana, IL, USA.
Neurosci Lett. 2002 Nov 8;332(3):180-4. doi: 10.1016/s0304-3940(02)00759-0.
Strengthening of synaptic connections has been proposed to underlie information storage in the brain, and experience-dependent increases in synapse number have been observed. However, the effect of these new synapses on the specific connectivity, and thus function, of a given brain area remains largely unknown. We report here that motor learning specifically induces the formation of multiple synapses--two post-synaptic contacts at a single pre-synaptic varicosity--in the cerebellum. Rats undergoing motor learning had more multiple synapses (two Purkinje cell spines contacting a given parallel fiber varicosity) per Purkinje cell than did active or inactive controls. The formation of multiple synapses provides an additional connection between a given parallel fiber and Purkinje cell, thereby enhancing particular pathways, and may constitute a fundamental mechanism of neural encoding.
突触连接的增强被认为是大脑中信息存储的基础，并且已经观察到依赖经验的突触数量增加。然而，这些新突触对给定脑区的特定连接性以及功能的影响在很大程度上仍然未知。我们在此报告，运动学习特别诱导了小脑中多个突触的形成——在单个突触前膨体处有两个突触后接触。进行运动学习的大鼠每个浦肯野细胞比活跃或不活跃的对照组有更多的多个突触（两个浦肯野细胞棘突接触给定的平行纤维膨体）。多个突触的形成在给定的平行纤维和浦肯野细胞之间提供了额外的连接，从而增强了特定通路，并且可能构成神经编码的基本机制。
