TY - JOUR
T1 - Differential effects of retinal degeneration on sleep and wakefulness responses to short light-dark cycles in albino mice
AU - Hsiao, F. C.
AU - Liao, Y. H.
AU - Tsai, L. L.
N1 - Funding Information:
We sincerely thank Meng-Ru Chuang, Chen-Hui Huang, Cheng-Yen Wu, Ya-Wen Liu, Li-Chi Yeh, and Pei-Ching Chen for their help on animal care and technical support to the experiments. This study was supported by National Science Council , Taiwan, ROC, Grants NSC95-2413-H-194-028-MY2 and NSC98-2410-H-194-022-MY2 . None of the authors has financial conflicts of interest.
PY - 2013/9/17
Y1 - 2013/9/17
N2 - This study characterizes the different response patterns of sleep and wakefulness (W) to short light-dark (LD) cycles in albino mice and examines whether retinal degeneration resulting from prolonged bright light treatment and/or rd/rd mutation alters such response patterns. Eight young male Institute for Cancer Research (ICR) mice with normal eyes, seven young male rd/rd Friend Virus B type (FVB) mice, six young ICR and five young rd/rd FVB mice receiving 48-h bright light treatment, and five older rd/rd FVB mice were implanted with skull and muscle electrodes to record sleep and W. All the mice were maintained in 12-h-12-h LD cycles at baseline and received 2. days of short LD cycle treatment, which included 5-min-5-min LD cycles for a total of 24 cycles presented 4. h after lights-on and again 4. h after lights-off. All the five mouse groups maintained photo-entrainment of sleep and W rhythms at the baseline and showed a preference for paradoxical sleep (PS) occurrence in the 5-min dark period and non-rapid eye movement sleep (NREMS) in the 5-min light period and a brief alerting effect of light onset on experimental days. Retinal degeneration rising from bright light treatment and/or genetic mutation failed to eliminate or reduce the response of PS and NREMS to short LD cycles, although it enhanced the LD contrast of W, i.e., bright light treatment prolonged the alerting effect of light and the rd mutation increased the suppressing effect of the dark on W. These results suggest that sleep responses to short LD cycles and the brief alerting effect of light were independent of the photoreceptors in the outer retina. Furthermore, the residual photoreceptors in the outer retina and/or the photosensitive cells in the inner retina may actively modulate the effect of light and dark signals on W.
AB - This study characterizes the different response patterns of sleep and wakefulness (W) to short light-dark (LD) cycles in albino mice and examines whether retinal degeneration resulting from prolonged bright light treatment and/or rd/rd mutation alters such response patterns. Eight young male Institute for Cancer Research (ICR) mice with normal eyes, seven young male rd/rd Friend Virus B type (FVB) mice, six young ICR and five young rd/rd FVB mice receiving 48-h bright light treatment, and five older rd/rd FVB mice were implanted with skull and muscle electrodes to record sleep and W. All the mice were maintained in 12-h-12-h LD cycles at baseline and received 2. days of short LD cycle treatment, which included 5-min-5-min LD cycles for a total of 24 cycles presented 4. h after lights-on and again 4. h after lights-off. All the five mouse groups maintained photo-entrainment of sleep and W rhythms at the baseline and showed a preference for paradoxical sleep (PS) occurrence in the 5-min dark period and non-rapid eye movement sleep (NREMS) in the 5-min light period and a brief alerting effect of light onset on experimental days. Retinal degeneration rising from bright light treatment and/or genetic mutation failed to eliminate or reduce the response of PS and NREMS to short LD cycles, although it enhanced the LD contrast of W, i.e., bright light treatment prolonged the alerting effect of light and the rd mutation increased the suppressing effect of the dark on W. These results suggest that sleep responses to short LD cycles and the brief alerting effect of light were independent of the photoreceptors in the outer retina. Furthermore, the residual photoreceptors in the outer retina and/or the photosensitive cells in the inner retina may actively modulate the effect of light and dark signals on W.
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U2 - 10.1016/j.neuroscience.2013.06.033
DO - 10.1016/j.neuroscience.2013.06.033
M3 - Article
C2 - 23811394
AN - SCOPUS:84880965662
SN - 0306-4522
VL - 248
SP - 459
EP - 468
JO - Neuroscience
JF - Neuroscience
ER -