posted on 2013-11-14, 00:00authored byNeil R. Smalheiser
A decade ago, RNA interference was proposed to serve as a physiologic means of
regulating long-term gene expression in the mammalian brain. However, during the
intervening years, this hypothesis appeared to be contradicted by both experimental data
and theoretical considerations. More recently, the advent of deep sequencing technology
has permitted a re-assessment of this issue. As reviewed here, a large population of small
RNAs having features characteristic of endogenous siRNAs are detected within adult
mouse hippocampus, which derive from genes involved in synaptic structure and
signaling, and which show a significant, though modest (16-22%) up-regulation during
olfactory discrimination training. Small RNAs derived from abundant cellular noncoding
RNAs are also detected; in particular, a subpopulation of RNAs 25-30 nt. in length shows
very large (>100 fold) up-regulation during olfactory discrimination training. Preliminary
data suggest that the 25-30 nt. RNAs may associate with MIWI rather than Argonaute 1-4
homologues. I conclude that, despite their apparent low abundance, endogenous siRNAs
and noncoding RNA-derived small RNAs are likely to play an important role in
regulating synaptic plasticity.
Funding
Research was supported by NIMH, NIDA and the Stanley Medical Research Institute.
History
Publisher Statement
NOTICE: This is the author’s version of a work that was accepted for publication in Experimental Neurology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Experimental Neurology, Vol 235, Issue 2, 2012 June DOI: 10.1016/j.expneurol.2011.10.015