Table 1.

Mean±SEM free-running period(τ, in hours) and activity phase length (α, in hours) of animals in DD and LL after 2 weeks of either control conditions or drug treatment

		Control	0.212% LiCl	Control	0.005% MAP
DD	τ	23.60	23.70	23.40	23.80
		(±0.23)	(±0.20)	(±0.08)	(±0.05)**
	α	13.55	14.95	14.87	18.51
		(±0.47)	(±0.43)*	(±0.68)	(±0.63)**
LL	τ	25.60	25.70	26.40	29.60
		(±0.47)	(±0.58)	(±0.12)	(±1.17)**
	α	11.10	10.40	12.80	14.32
		(±0.87)	(±0.69)	(±0.66)	(±0.94)

N in DD=15 LiCl-treated mice and 20 MAP-treated mice. N in LL = 12 LiCl-treated mice and 22 MAP-treated mice.

DD, constant darkness; LiCl, lithium chloride; LL, constant light; MAP, methamphetamine.

^*P< 0.05,

^**P< 0.001 as compared with control conditions.