title: Brief dark exposure restored ocular dominance plasticity in aging mice and after a cortical stroke.
abstract: In the primary visual cortex (V1), monocular deprivation (MD) induces a shift in the ocular dominance (OD) of binocular neurons towards the open eye (Wiesel and Hubel, 1963; Gordon and Stryker, 1996). In V1 of C57Bl/6J mice, this OD-plasticity is maximal in juveniles, declines in adults and is absent beyond postnatal day (PD) 110 (Lehmann and Löwel, 2008) if mice are raised in standard cages. Since it was recently shown that brief dark exposure (DE) restored OD-plasticity in young adult rats (PD70-100) (He et al., 2006), we wondered whether DE would restore OD-plasticity also in adult and old mice and after a cortical stroke. To this end, we raised mice in standard cages until adulthood and transferred them to a darkroom for 10-14 days. Using intrinsic signal optical imaging we demonstrate that short-term DE can restore OD-plasticity after MD in both adult (PD138) and old mice (PD535), and that OD-shifts were mediated by an increase of open eye responses in V1. Interestingly, restored OD-plasticity after DE was accompanied by a reduction of both parvalbumin expressing cells and perineuronal nets and was prevented by increasing intracortical inhibition with diazepam. DE also maintained OD-plasticity in adult mice (PD150) after a stroke in the primary somatosensory cortex. In contrast, short-term DE did not affect basic visual parameters as measured by optomotry. In conclusion, short-term DE was able to restore OD-plasticity in both adult and aging mice and even preserved plasticity after a cortical stroke, most likely mediated by reducing intracortical inhibition.
authors.affiliation: Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany; Bernstein Fokus Neurotechnologie (BFNT) and Johann-Friedrich-Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, Von-Siebold-Str. 6, D-37075 Göttingen, Germany. Electronic address: sstodie@gwdg.de.
authors.forename: Sophia Katharina
authors.initials: SK
authors.lastname: Stodieck
authors.affiliation: Bernstein Fokus Neurotechnologie (BFNT) and Johann-Friedrich-Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, Von-Siebold-Str. 6, D-37075 Göttingen, Germany. Electronic address: Franziska.Greifzu@biologie.uni-goettingen.de.
authors.forename: Franziska
authors.initials: F
authors.lastname: Greifzu
authors.affiliation: Bernstein Fokus Neurotechnologie (BFNT) and Johann-Friedrich-Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, Von-Siebold-Str. 6, D-37075 Göttingen, Germany. Electronic address: bianka.goetze@biologie.uni-goettingen.de.
authors.forename: Bianka
authors.initials: B
authors.lastname: Goetze
authors.affiliation: Bernstein Fokus Neurotechnologie (BFNT) and Johann-Friedrich-Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, Von-Siebold-Str. 6, D-37075 Göttingen, Germany. Electronic address: kfschmidt29@gmail.com.
authors.forename: Karl-Friedrich
authors.initials: KF
authors.lastname: Schmidt
authors.affiliation: Bernstein Fokus Neurotechnologie (BFNT) and Johann-Friedrich-Blumenbach Institut für Zoologie und Anthropologie, Universität Göttingen, Von-Siebold-Str. 6, D-37075 Göttingen, Germany; Sensory Collaborative Research Center 889, University of Göttingen, D-37075 Göttingen, Germany. Electronic address: sloewel@gwdg.de.
authors.forename: Siegrid
authors.initials: S
authors.lastname: Löwel
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D015350:Contrast Sensitivity / Q000502:physiology; D003624:Darkness; D003975:Diazepam / Q000494:pharmacology; D023882:Dominance, Ocular / Q000187:drug effects / Q000502:physiology*; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009473:Neuronal Plasticity / Q000502:physiology; D010320:Parvalbumins / Q000378:metabolism; D051381:Rats; D012683:Sensory Deprivation / Q000502:physiology; D013003:Somatosensory Cortex / Q000503:physiopathology; D020521:Stroke / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology* / Q000503:physiopathology
chemical_list: D010320:Parvalbumins; D003975:Diazepam
keywords: Aging; Dark exposure; Intracortical inhibition; Monocular deprivation; Ocular dominance plasticity; Optical imaging; Photothrombosis; Visual cortex