Neuroanatomical distribution and neurochemical characterization of cells expressing adenylyl cyclase isoforms in mouse and rat brain

Transmembrane adenylyl cyclases (Adcy) are involved in the regulation of multiple brain processes such as synaptic plasticity, learning and memory. They synthesize intracellular cyclic adenosine monophosphate (cAMP) following activation by G-protein coupled receptors. We examined the neuroanatomical distribution of the nine Adcy isoforms in rat and mouse brain by in situ hybridization, as well as their location in glutamatergic, GABAergic and cholinergic neurons in several mouse brain areas by double in situ hybridization. The Adcys are widely distributed throughout the brain in both rat and mouse, being especially abundant in cortex, hippocampus, thalamic nuclei, the olfactory system and the granular layer of the cerebellum. Double-labeling experiments showed that Adcy isoforms are differently expressed in glutamatergic, GABAergic and cholinergic neuronal cell populations. We report the neuroanatomical distribution of the nine known Adcy isoforms in rat and mouse brain and their cellular localization.

Research highlights▶ Differences in mRNA expression of some Adcy isoforms (Adcy1, Adcy2, Adcy5 and Adcy8) were observed between rat and mouse hippocampal fields. ▶ Adcy2 mRNA expression was found expressed in all striatal cholinergic cells. ▶ Different GABAergic populations of the striatum expressed Adcy1 and Adcy5 mRNA in a differential manner.