Clocking In Time to Gate Memory Processes: The Circadian Clock Is Part of the Ins and Outs of Memory

Table 1

Circadian modulation of memory-relevant signaling in rodents.

Signaling molecule	Short-term memory	Model organism	Long-term memory	Model organism	Memory retrieval	Model organism	Circadian/diurnal rhythmicity	Model organism
cAMP	✓	Wistar rats [104]	✓	C57BL/6 × 129/Ola mice [105]	—		✓	C57/BL6 mice [69]
PKA	X	C57BL/6J mice [47, 106]; Sprague-Dawley rats [107]	✓	C57BL/6J mice [106, 108]; Sprague-Dawley rats [107]	—		✓	C3H/H3N mice [64]
PKC	✓	Wistar rats [109, 110]	✓	Wistar rats [111]	✓	CD1 mice [112]	✓	C3H/HeN [64] mice
pMAPK	—		✓	C57/BL6 [113]	✓	C57BL/6 [114, 115]	✓	C57/BL6 mice [69, 116]
pCREB	X	Wistar rats [117]; Long-Evans hooded rats [118]	✓	Wistar rats [117]; Long-Evans hooded rats [118]	X	C57BL/6 mice [119]	✓	C3H/H3N mice [64]; C57/BL6 mice [69]
AC	✓	C57BL/6 × 129/SV mice [120]	✓	C57BL/6 × 129/SV mice [120]	—		—
CAMKIV	X	C57BL/6N mice [121]	✓	C57BL/6 mice [122]	—		✓	WKY rats [123]
CAMKII	X	129/BL6 mice [124]	✓	129/BL6 mice [124]	X	Wistar rats [125]	✓	C57BL/6 mice [116, 126]

✓: effect; X: no effect; —: unknown; cAMP: cyclic-adenosine monophosphate; PKA: protein kinase A; PKC: protein kinase C; pMAPK: phosphorylated mitogen-activated protein kinase; pCREB: phosphorylated cAMP response element-binding protein; AC: adenylyl cyclase; CAMKIV: calcium/calmodulin-dependent protein kinase type IV; CAMKII: calcium/calmodulin-dependent protein kinase type II.