Modulation of synaptic zinc in barrel cortex by whisker stimulation.

Abstract:

:The cortical representation of the body surface is not fixed, but rather, is continuously modified by ongoing changes in sensory experience. Although the cellular and molecular mechanisms that subserve these changes are uncertain, increasing evidence suggests that synaptically-released zinc may play a role. Zinc is released from a subset of glutamatergic neurons and can modulate postsynaptic excitability by regulating the activation of glutamate and GABA receptor-gated ion channels. Previously, we have shown that whisker plucking, a manipulation commonly used to induce cortical map plasticity, results in a rapid and robust increase in staining levels for synaptic zinc in deprived regions of the barrel cortex. In the present study, we examined the effect of increased whisker activity, analogous to what may happen during tactile learning or exploratory behavior in a natural setting, on synaptic zinc levels in the adult barrel cortex. Our results indicate that stimulation of whiskers caused a selective decrease in zinc levels within layer 4 of the barrel hollow corresponding to the stimulated whisker. Quantitatively, levels of staining were significantly reduced at 3 h, and showed even greater reductions following 12 and 24 h of stimulation. However, these changes were not long-lasting, as levels of staining in the stimulated barrel returned to control values within 24 h after stimulation had ceased. These data indicate that zincergic circuits are highly sensitive to ongoing changes in sensory experience and may participate in moment-to-moment changes in the functional connectivity of the cerebral cortex.

journal_name

Neuroscience

journal_title

Neuroscience

authors

Brown CE,Dyck RH

doi

10.1016/j.neuroscience.2005.05.011

keywords:

subject

Has Abstract

pub_date

2005-01-01 00:00:00

pages

355-9

issue

2

eissn

0306-4522

issn

1873-7544

pii

S0306-4522(05)00545-2

journal_volume

134

pub_type

杂志文章