Regional and cellular distribution of DREAM in adult rat brain consistent with multiple sensory processing roles

We used immunohistochemistry to map the recently discovered EF-hand protein, DREAM (downstream regulatory element antagonist modulator), and compare its expression in rat brain with that of other key neural proteins. DREAM immunoreactivity was most intense in cerebellar granular cortex. That expression pattern matches one reported for Kv4.2, an interaction partner of DREAM in regulation of potassium channels. On the other hand, the regional and cellular expression of DREAM in cerebellum was opposite to that of calbindin D(28k). Other loci for DREAM expression included the hippocampus and retrosplenial granular cortex, which share afferent and efferent connections. A notable trend, however, was the consistent appearance of DREAM at primary sites for sensory processing. These included the optic tract, superior colliculus, olfactory bulb, and several thalamic relay centers such as the anterior dorsal, medial geniculate, dorsolateral geniculate, ventral posteromedial and ventral posterolateral nuclei. Altogether, the results are consistent with multiple functions for DREAM, including a potential role in transfer of sensory information.