Present address: Kavli Institute for Systems Neuroscience and Centre for the Biology of Memory, Norwegian University of Science and Technology, 7489 Trondheim, Norway.
Behaviorally evoked transient reorganization of hippocampal spines
Article first published online: 10 AUG 2009
© The Authors (2009). Journal Compilation © Federation of European Neuroscience Societies and Blackwell Publishing Ltd
European Journal of Neuroscience
Volume 30, Issue 4, pages 560–566, August 2009
How to Cite
Kitanishi, T., Ikegaya, Y. and Matsuki, N. (2009), Behaviorally evoked transient reorganization of hippocampal spines. European Journal of Neuroscience, 30: 560–566. doi: 10.1111/j.1460-9568.2009.06860.x
- Issue published online: 24 AUG 2009
- Article first published online: 10 AUG 2009
- Received 24 February 2009, revised 20 May 2009, accepted 23 June 2009
- dendritic spine;
- immediate-early gene;
- sparse coding
Dendritic spines, microstructures that receive the majority of excitatory synaptic inputs, are fundamental units to integrate and store neuronal information. The morphological reorganization of spines accompanies the functional alterations in synaptic strength underlying memory-relevant modifications of network connectivity. Here we report the rapid dynamics of cell population-selective spine reorganizations related to behavioral experiences. In Thy1-GFP transgenic mice, hippocampal CA1 pyramidal neurons that were putatively activated during environmental explorations were detected with their post hoc immunoreactivity for Arc, an activity-dependent immediately-early gene. Immediately after a 60-min exposure to a familiar environment, the spine densities of Arc-positive and Arc-negative neurons were differently distributed. This density imbalance was due exclusively to changes in the number of small, rather than large, spines. The change disappeared within 60 min after mice were returned to the home cages. Thus, spines possess the ability to rapidly and reversibly alter their morphology in response to a brief environmental change. We propose that these transient spine dynamics represent a latent preliminary stage for longer-term plasticity on demand.