Distribution of mRNA for the calmodulin-sensitive adenylate cyclase in rat brain: expression in areas associated with learning and memory

Z Xia, CD Refsdal, KM Merchant, DM Dorsa, DR Storm - Neuron, 1991 - cell.com
Z Xia, CD Refsdal, KM Merchant, DM Dorsa, DR Storm
Neuron, 1991cell.com
The Drosophila learning mutant, rutabaga, is deficient in the calmodulin-sensitive adenylate
cyclase, and studies of associative learning in Aplysia have implicated this enzyme in
neuroplasticity. Therefore, the distribution of mRNA encoding the calmodulin-sensitive
adenylate cyclase in rat brain was examined by in situ hybridization. mRNA for this enzyme
is expressed in specific areas of brain that have been implicated in learning and memory,
including the neocortex, the hippocampus, and the olfactory system. The presence of mRNA …
Summary
The Drosophila learning mutant, rutabaga, is deficient in the calmodulin-sensitive adenylate cyclase, and studies of associative learning in Aplysia have implicated this enzyme in neuroplasticity. Therefore, the distribution of mRNA encoding the calmodulin-sensitive adenylate cyclase in rat brain was examined by in situ hybridization. mRNA for this enzyme is expressed in specific areas of brain that have been implicated in learning and memory, including the neocortex, the hippocampus, and the olfactory system. The presence of mRNA for this enzyme in the pyramidal and granule cells of the hippocampal formation provides evidence that it is found in neurons. These data are consistent with the proposal that the calmodulin-sensitive adenylate cyclase plays an important role in learning and memory. introduction
Adenylate cyclases catalyze the formation of CAMP, which is an important intracellular messenger in eukaryotic cells, including neurons of the central nervous system (Chen et al., 1986; Greenberg et al., 1987; Levitzki, 1987). In mammalian brain, adenylate cyclase activity is regulated byneurotransmitterand hormone receptors coupled to the enzyme through the G regulatory proteins, G, and Gi (reviewed by Ross and Gilman, 1980), as well as by intracelular free Ca2+(reviewed by Cheung and Storm, 1982). Protein phosphorylations catalyzed by the CAMP-dependent protein kinase regulate several important aspects of neuronal function, including ion channel activity, gene expression, and neurotransmitter synthesis (reviewed by Krebs ad Beavo, 1979; Nestler and Greengard, 1983; Nairn et al., 1985). Furthermore, CAMP has been implicated in the regulation of synaptic plasticity and may play an important role in mechanisms underlying learning and memory (reviewed in Kandel and Schwartz, 1982; Dudai, 1988). It was originally proposed by Brostrom et al.(1975) that Ca2+ stimulation of brain adenylate cyclase is mediated by calmodulin (CaM) and that brain contains a mixtureof CaM-sensitive and CaM-insensitiveadenyl-
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