Original Research ARTICLE

Front. Syst. Neurosci., 09 April 2012 | http://dx.doi.org/10.3389/fnsys.2012.00022

Recovery of neurofilament following early monocular deprivation

  • Department of Psychology, Life Sciences Centre, Dalhousie University, Halifax, NS, Canada

Postnatal development of the mammalian geniculostriate visual pathway is partly guided by visually driven activity. Disruption of normal visual input during certain critical periods can alter the structure of neurons, as well as their connections and functional properties. Within the layers of the dorsal lateral geniculate nucleus (dLGN), a brief early period of monocular deprivation can alter the structure and soma size of neurons within deprived-eye-receiving layers. This modification of structure is accompanied by a marked reduction in labeling for neurofilament protein, a principle component of the stable cytoskeleton. This study examined the extent of neurofilament recovery in monocularly deprived cats that either had their deprived eye opened (binocular recovery), or had the deprivation reversed to the fellow eye (reverse occlusion). The loss of neurofilament and the reduction of soma size caused by monocular deprivation were ameliorated equally and substantially in both recovery conditions after 8 days. The degree to which this recovery was dependent on visually driven activity was examined by placing monocularly deprived animals in complete darkness. Though monocularly deprived animals placed in darkness showed recovery of soma size in deprived layers, the manipulation catalyzed a loss of neurofilament labeling that extended to non-deprived layers as well. Overall, these results indicate that both recovery of soma size and neurofilament labeling is achieved by removal of the competitive disadvantage of the deprived eye. However, while the former occurred even in the absence of visually driven activity, recovery of neurofilament did not. The finding that a period of darkness produced an overall loss of neurofilament throughout the dLGN suggests that this experiential manipulation may cause the visual pathways to revert to an earlier more plastic developmental stage. It is possible that short periods of darkness could be incorporated as a component of therapeutic measures for treatment of deprivation-induced disorders such as amblyopia.

Keywords: neurofilament, cytoskeleton, monocular deprivation, reverse occlusion, dark-rearing, recovery, lateral geniculate nucleus, plasticity

Citation: O'Leary TP, Kutcher MR, Mitchell DE, and Duffy KR (2012) Recovery of neurofilament following early monocular deprivation. Front. Syst. Neurosci. 6:22. doi: 10.3389/fnsys.2012.00022

Received: 03 January 2012; Accepted: 17 March 2012;
Published online: 09 April 2012.

Edited by:

Andrew J. Parker, University of Oxford, UK

Reviewed by:

Gregor Rainer, University of Fribourg, Switzerland
Preston E. Garraghty, Indiana University, USA

Copyright: © 2012 O'Leary, Kutcher, Mitchell and Duffy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non Commercial License, which permits non-commercial use, distribution, and reproduction in other forums, provided the original authors and source are credited.

*Correspondence: Kevin R. Duffy, Department of Psychology/Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada. e-mail: kevin.duffy@dal.ca