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  • Neuroscience

Published online: 18 June 2008 | doi:10.1038/nchina.2008.138

Synaptic development: Mega memory

Felix Cheung

Introduction

© (2008) Nature Neuroscience

There are different types of ion channels in the cell membrane of neurons that allow specific ions — in other words, signals — to permeate through. For instance, transient receptor potential canonical (TRPC) channels are a family of Ca²⁺-permeable ion channels responsible for sensation. Yizheng Wang and co-workers at the Chinese Academy of Science in Shanghai¹ have discovered a previously unknown role of one of these channels, TRPC6, in synaptic development, as well as learning and memory.

Wang and co-workers stained cultured rat hippocampal neurons with an antibody specific to TRPC6. Fluorescence (pictured top) and electron microscopy images (pictured bottom) showed that TRPC6 was mainly localized in signal-receiving (postsynaptic) sites of hippocampal neurons.

The finding suggests that TRPC6 may affect the synaptic development, particularly the formation of dendritic spines and excitatory synapses. The researchers therefore investigated the effect of overexpressed TRPC6 in cultured hippocampal neurons. They found that the dendritic-spine and excitatory-synapse densities were greatly increased.

The researchers then generated transgenic mice in which TRPC6 expression was enhanced in the forebrain. They tested the hippocampus-dependent spatial memory of transgenic mice in comparison with normal mice using the Morris water maze — a circular water-bath with an escape platform randomly placed in one of the quadrants.

Transgenic mice became substantially faster at escaping after days of training. Moreover, they devoted much more time to searching for the targeted quadrant and had more success in escaping than normal mice. These results indicate that TRPC6 enhances spatial learning and memory, at least in mice.

The authors of this work are from:
Laboratory of Neural Signal Transduction, Institute of Neuroscience, Shanghai Institutes of Biological Sciences, State Key Laboratory of Neuroscience, Chinese Academy of Science, Shanghai, China; Graduate University of Chinese Academy of Science, Shanghai, China.

Reference

1. Zhou, J. et al. Critical role of TRPC6 channels in the formation of excitatory synapses. Nature Neurosci. doi: 10.1038/nn.2127 (2008).  | Article |