Synaptic scaling is an extensively studied form of homeostatic plasticity critically involved in various brain functions. Although it is accepted that synaptic scaling is expressed through the postsynaptic accumulation of AMPA receptors (AMPARs), the induction mechanism remains elusive. In this study, we show that TTX treatment induces rapid but transient release of the neurite growth-promoting factor 2 (NGPF2), and this release is necessary and sufficient for TTX-induced scaling up. In addition, we show that inhibition of the anaplastic lymphoma kinase (ALK)-LIMK-cofilin signaling pathway blocks TTX- and NGPF2-induced synaptic scaling up. Furthermore, we show that TTX-induced release of NGPF2 is protein synthesis dependent and requires fragile X mental retardation protein 1 (FMRP1). These results indicate that activity blockade induces NGPF2 synthesis and release to trigger synaptic scaling up through LIMK-cofilin-dependent actin reorganization, spine enlargement, and stabilization of AMPARs at the synapse.Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.
About The Expert
Zikai Zhou
Guiqin He
Xiaoyun Zhang
Xin Lv
Xiaolin Zhang
An Liu
Shuting Xia
Hao Xie
Rui Dang
Lifang Han
Junxia Qi
Yanghong Meng
Shunying Yu
Wei Xie
Zhengping Jia
References
PubMed