Table 1.

Summary of brain structures assayed for circadian rhythmicity in Per1-luc bioluminescence

Rhythmic areas	% Rhythmic (n)	Damp rate (cycles)	Phase (hr)	Arrhythmic areas	n
SCN	100  (42)	>10	9.7  ± 0.5	Au1	2
Pin	100  (10)	1.3  ± 0.4	21.2  ± 0.2	BNSTp	3
Pit	100  (16)	2.9  ± 0.3	14.3  ± 0.8	CE	3
RCH	100  (4)	1.8  ± 0.1	11.7  ± 0.1	CP	5
ME	100  (2)	1.3  ± 0.3	11.5  ± 1.8	DR	6
OB	100  (6)	1.6  ± 0.4	11.5  ± 0.3	HI	13
AN	95  (19)	1.7  ± 0.2	14.3  ± 0.7	M1p	3
PVN	92  (12)	1.0  ± 0.0	17.1  ± 0.6	MR	3
LH	75  (4)	0.8  ± 0.3	14.4  ± 3.4	MS	7
VOLT	50  (8)	0.8  ± 0.5	17.3  ± 2.3	NA	6
VLPO	43  (7)	1.1  ± 0.5	18.7  ± 1.8	PC	10
PVT	40  (5)	1.0  ± 0.0	22.4  ± 5.6	S1	8
SON	38  (8)	0.4  ± 0.2	13.0  ± 3.1	SN	7
				VTA	4

Cultures that showed at least two peaks with a near 24 hr period were defined as rhythmic (see Materials and Methods). The numbers of explants studied are indicated in parentheses. Damping rate is the number of circadian cycles that exceeded 30% of the magnitude of the first cycle (mean ± SEM; see Materials and Methods), and phase is the time of the first circadian peak relative to the animal's previous light cycle in which dawn and dusk occurred at 0 and 12 hr, respectively.