DOI: 10.5061/dryad.t1g1jwtb0
title: Relative importance of intensity and spectrum of artificial light at night in disrupting behavior of a nocturnal rodent

description: The influence of light spectral properties on circadian rhythms is of
 substantial interest to laboratory-based investigation of the circadian
 system and to field-based understanding of the effects of artificial light
 at night. The tradeoffs between intensity and spectrum regarding masking
 behaviors are largely unknown, even for well-studied organisms. We used a
 custom LED illumination system to document the response of wild type house
 mice (Mus musculus) to 1-hr nocturnal exposure of all combinations of four
 intensity levels (0.01, 0.5, 5, and 50 lx) and three correlated color
 temperatures (CCT; 1750, 1950, and 3000 K). Higher intensities of light
 (50 lx) suppressed cage activity substantially, and consistently more for
 the higher CCT light (91% for 3000 K; 53% for 1750 K). At the lower
 intensities (0.01 lx), mean activity was increased, with the greatest
 increases for the lowest CCT (12.3% increase at 1750 K; 3% increase at
 3000 K). Multiple linear regression confirmed the influence of both CCT
 (p&lt;0.001) and intensity (p&lt;0.001) on changes in
 activity (r2=0.66, F9,171=3.33; p&lt;0.001) with the scaled effect
 size of intensity 3.6 times greater than CCT. Activity suppression was
 significantly lower for male than female mice (p&lt;0.0001).
 Assessment of light-evoked cFos expression in the suprachiasmatic nucleus
 at 50 lx showed no significant difference between high and low CCT
 exposure. The significant differences by spectral composition illustrate a
 need to account for light spectrum in circadian studies of behavior and
 confirm that spectral controls can mitigate some, but certainly not all,
 of the effects of light pollution on species in the wild.
description: # Relative importance of intensity and spectrum of artificial light at
 night in disrupting behavior of a nocturnal rodent
 [https://doi.org/10.5061/dryad.t1g1jwtb0](https://doi.org/10.5061/dryad.t1g1jwtb0) Three datasets: 1. Change in activity (suppression) at night from a 1 hr exposure of light at three different correlated color temperatures (CCT) and four different intensities (measured in lx). 2. Number of cFos+ cells at two CCTs after a 50 lx exposure. 3. Spectral power distribution of the experimental lamps at different CCTs ## Description of the data and file structure There are three csv files containing the three datasets. **SuppressionDataset.csv** Intensity (lx) -- brightness of the light measured at the bottom of the enclosure in lux (human-weighted irradiance). CCT -- correlated color temperature of the light source sex - male (M) or female (F) Mouse Number - unique identifier for each mouse Suppression - degree to which activity decreased (positive numbers) or increased (negative numbers) , ranges -1 to 1 **cFosdata.csv** CCT - correlated color temperature of experimental lamp (see SPD.csv for spectral power distribution) Number cFos+ Cells -- number of cFos positive cells observed **SPD.csv** wavelength - bins of 1-nm wavelengths in nanometers SPD - power emitted within 1-nm band Lamp -- name of lamp (Ecosense 1750 K, Ecosense 1950 K, and Ecosense 3000 K)