The role of Ca2+/calmodulin-stimulable adenylyl cyclases as molecular coincidence detectors in memory formation.
Evidence from systems as diverse as mollusks, insects and mammals has revealed that adenylyl cyclase, cyclic adenosine 3',5'-monophosphate (cAMP) cascade, cAMP-dependent protein kinases and their substrates are required for the cellular events underlying the short-term and long-term forms of memory. In Aplysia and Drosophila models, the coincident activation of independent paths converge to produce a synergistic activation of Ca2+/calmodulin-stimulable adenylyl cyclase, thereby enhancing the cAMP level that appears as the primary mediator of downstream events that strengthen enduring memory. In mammals, in which long-term memories require hippocampal function, our understanding of the role of adenylyl cyclases is still fragmentary. Of the differently regulated isoforms present in the hippocampus, the susceptibility of type 1 and type 8 to stimulation by the complex Ca2+/calmodulin and their expression in the hippocampus suggest a role for these two isoforms as a molecular coincidence device for hippocampus-related memory function. Here, we review the key features of Ca2+/calmodulin stimulable adenylyl cyclases, as well as the involvement of cAMP-regulated signaling pathway in the processes of learning and memory.
Mons
N
N
Laboratoire de Neurosciences Comportementales et Cognitives, UMR 5807, Université de Bordeaux 1, Talence, France. mons@neurocog.u-bordeaux.fr
Guillou
J L
JL
Jaffard
R
R
D000262:Adenylyl Cyclases / Q000235:genetics / Q000502:physiology*; D000818:Animals; D002118:Calcium; D002147:Calmodulin; D007448:Invertebrates / Q000201:enzymology / Q000502:physiology; D007858:Learning / Q000502:physiology; D008568:Memory / Q000502:physiology*; D013569:Synapses
D002147:Calmodulin; D000262:Adenylyl Cyclases; D002118:Calcium