Long wavelength light reduces the negative consequences of dim light at night

Huei-Bin Wang; David Zhou; Shu Hon Christopher Luk; Hye In Cha; Amanda Mac; Rim Chae; Anna Matynia; Ben Harrison; Sina Afshari; Gene D Block; Cristina A Ghiani; Christopher S Colwell

doi:10.1016/j.nbd.2022.105944

Long wavelength light reduces the negative consequences of dim light at night

Neurobiol Dis. 2023 Jan:176:105944. doi: 10.1016/j.nbd.2022.105944. Epub 2022 Dec 6.

Authors

Affiliations

¹ Molecular, Cellular, Integrative Physiology Graduate Program, David Geffen School of Medicine, University of California Los Angeles, USA; Department of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, USA.
² Department of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, USA.
³ Laboratory of Ocular Molecular and Cellular Biology and Genetics, Jules Stein Eye Institute, David Geffen School of Medicine, University of California Los Angeles, USA.
⁴ Korrus Inc, Los Angeles, CA, USA.
⁵ Department of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, USA; Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, USA; Intellectual and Developmental Disabilities Center, David Geffen School of Medicine, University of California Los Angeles, USA.
⁶ Department of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, USA; Intellectual and Developmental Disabilities Center, David Geffen School of Medicine, University of California Los Angeles, USA. Electronic address: ccolwell@mednet.ucla.edu.

Abstract

Many patients with autism spectrum disorders (ASD) show disturbances in their sleep/wake cycles, and they may be particularly vulnerable to the impact of circadian disruptors. We have previously shown that a 2-weeks exposure to dim light at night (DLaN) disrupts diurnal rhythms, increases repetitive behaviors and reduces social interactions in contactin-associated protein-like 2 knock out (Cntnap2 KO) mice. The deleterious effects of DLaN may be mediated by intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin, which is maximally sensitive to blue light (480 nm). In this study, the usage of a light-emitting diode array enabled us to shift the spectral properties of the DLaN while keeping the intensity of the illumination at 10 lx. First, we confirmed that the short-wavelength enriched lighting produced strong acute suppression of locomotor activity (masking), robust light-induced phase shifts, and cFos expression in the suprachiasmatic nucleus in wild-type (WT) mice, while the long-wavelength enriched lighting evoked much weaker responses. Opn4^DTA mice, lacking the melanopsin expressing ipRGCs, were resistant to DLaN effects. Importantly, shifting the DLaN stimulus to longer wavelengths mitigated the negative impact on the activity rhythms and 'autistic' behaviors (i.e. reciprocal social interactions, repetitive grooming) in the Cntnap2 KO as well as in WT mice. The short-, but not the long-wavelength enriched, DLaN triggered cFos expression in in the basolateral amygdala (BLA) as well as in the peri-habenula region raising that possibility that these cell populations may mediate the effects. Broadly, our findings are consistent with the recommendation that spectral properties of light at night should be considered to optimize health in neurotypical as well as vulnerable populations.

Keywords: Amygdala; Autism spectrum disorder; Circadian; Cntnap2 knock out; Light pollution; Melanopsin; Mice; cFos.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Circadian Rhythm* / physiology
Light
Membrane Proteins / metabolism
Mice
Nerve Tissue Proteins / metabolism
Retinal Ganglion Cells* / metabolism
Suprachiasmatic Nucleus

Substances

CNTNAP2 protein, mouse
Membrane Proteins
Nerve Tissue Proteins

Abstract

Publication types

MeSH terms

Substances

Grants and funding