Table 3.

Daylength and squared daylength have significant effects on brain regional MOR availability in rats in both simplified and full statistical models.

ROIs	Factors	β	95% CI	t	Marginal R2	AIC
Daylength and Squared daylength as fixed-effect factors
Neocortex	Daylength	0.2	0.1 to 0.28	4.14	0.33	24.28
	Squared daylength	−0.008	−0.012 to −0.0045	−4.27
Striatum	Daylength	0.25	0.11 to 0.38	3.57	0.26	48.16
	Squared daylength	−0.01	−0.017 to −0.005	−3.64
Thalamus	Daylength	0.25	0.11 to 0.4	3.43	0.33	48.16
	Squared daylength	−0.01	−0.017 to −0.005	−3.75
Full model
Neocortex	Daylength	0.20	0.12 to 0.29	4.61	0.39	38.66
	Squared daylength	−0.008	−0.012 to −0.0047	−4.46
Striatum	Daylength	0.25	0.11 to 0.39	3.49	0.30	60.17
	Squared daylength	−0.01	−0.017 to −0.004	−3.64
Thalamus	Daylength	0.28	0.14 to 0.43	3.89	0.39	61.30
	Squared daylength	−0.01	−0.018 to −0.006	−3.79