. Author manuscript; available in PMC: 2020 Jan 30.

Published in final edited form as: Eur J Neurosci. 2018 Jul 30:10.1111/ejn.14092. doi: 10.1111/ejn.14092

Table 1:

Cycling in Circadian Circuits

Neuronal group:	Cycling:	Highest at: (hours since lights-on)	Cycles in constant darkness?	Cycle lost in a clock mutant?:	Reference
Clock neurons
s-LNv	Electrical activity	~0	N.d.	N.d.	(Cao & Nitabach, 2008)
	Intracellular calcium (Ca²⁺) levels	23-24	Yes	Yes	(Liang et al., 2016)
	Complexity of projections	~0	Yes	Yes	(Fernández et al., 2008)
	Synapse contacts	~2	Yes	N.d.	(Gorostiza et al., 2014)
	Rho1 activity	~12	Yes	Yes	(Petsakou et al., 2015)
	PDF levels in projections	0-6	Yes	Yes	(Park et al., 2000)
	PDF and dopamine sensitivity	~0	Yes	N.d.	(Klose et al., 2016)
l-LNv	Electrical activity	1-6	No (DD day 1); Yes (DD day 14)	Yes	(Cao & Nitabach, 2008; Sheeba, Gu, et al., 2008)
	Ca²⁺ levels	5-6	Yes	Yes	(Liang et al., 2016)
	GABA sensitivity	Evening	N.d.	N.d.	(Li et al., 2017)
LNd	Ca²⁺ levels	~12	Yes (highest at CT 8-9)	Yes	(Liang et al., 2016)
DN1	Electrical activity	0-4 or 20-24	N.d.	Yes	(Flourakis et al., 2015)
DN1	Ca²⁺ levels	18-20	Yes	Yes	(Liang et al., 2016)
DN2	Synaptic contacts with s-LNvs	22-24	N.d.	N.d.	(Tang et al., 2017)
DN3	Ca²⁺ levels	17-18	Yes	Yes	(Liang et al., 2016)
Circadian output neurons
DILP2⁺ PI	Electrical activity	0-4	No	Yes	(Barber et al., 2016)
DH44⁺ PI	Ca²⁺ levels	7-12	Yes	Yes	(Cavey et al., 2016; Bai et al., 2018)
Hugin⁺ SEZ	Neuropeptide vesicle release	Night	N.d.	Yes	(King et al., 2017)
LK⁺ LH	Ca²⁺ levels	Night	Yes	Yes	(Cavey et al., 2016)
LK⁺ LH	Carbachol sensitivity	Night	Yes	Yes	(Cavey et al., 2016)
LK Receptor⁺ LH	Ca²⁺ levels	Day	Yes	Yes	(Cavey et al., 2016)
LK Receptor⁺ LH	Carbachol sensitivity	Day	Yes	Yes	(Cavey et al., 2016)

N.d. = not determined

CT = circadian time

DD = constant darkness

LH = lateral horn

PI = pars intercerebralis

SEZ = subesophageal zone