[Abstract Title]. - Society for Neuroscience

Poster
239. Structural Plasticity at Synapses I
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 239.4/E1
Topic: B.08.i. Structural plasticity
Support: KAKENHI 17021011
KAKENHI 20019016
KAKENHI 19590060
Title: Acute and coordinated spine reorganization in behaviorally activated neurons
Authors: *T. KITANISHI, Y. IKEGAYA, N. MATSUKI, M. K. YAMADA;
Lab. Chem Pharmacol, Grad Sch. Pharm Sci, Univ. Tokyo, Tokyo, Japan
Abstract: Morphological plasticity of dendritic spines underlies the fine-tuning of network
connectivity. The relationship between spine plasticity and experience-dependent neuronal
activities, however, is largely unknown. We simultaneously imaged spine morphology and Arc
(Arg3.1, an immediate-early gene that serves as a cellular marker of past neuronal activity)
expression using Thy1-mGFP transgenic mice after exploration in novel environment for either
15 or 60 min. After the exploring sessions, Arc was detected in 25% of hippocampal CA1
neurons. We found that, after 60 min of exploration, Arc-positive cells possessed fewer small
spines and more large spines compared with Arc-negative cells, although these parameters
showed no difference after 15 min of exploration. Further, the number of extra-large spines
showed inverse correlation with that of small spines in the 60-min mice. These results provide
the first evidence of acute (but not immediate) and coordinated morphological changes in spines
selective in behaviorally activated Arc-expressing neurons.
Disclosures: T. Kitanishi, None; Y. Ikegaya, None; N. Matsuki, None; M.K. Yamada, None.
Poster
239. Structural Plasticity at Synapses I