Spontaneous calcium changes in striatal cells

The striatum plays an important role in linking cortical activity to basal ganglia outputs. We performed calcium (Ca 2+ ) imaging to investigate the spontaneous activities of the striatum using acute slice preparations. Corticostriatal slices of rats were stained with Fura‐PE3‐AM. Long ‐lasting spontaneous intracellular Ca 2+ ([Ca 2+ ] i ) changes, which lasted up to several hundred seconds, were observed. The amplitudes and the intervals of the changes were variable even in a single cell. Most cells exhibited irregular frequencies, but some exhibited oscillatory features. Most of these [Ca 2+ ] i changes were not suppressed by TTX, a blocker of action potentials. The number of active cells, which exhibited the [Ca 2+ ] i changes, was greatly reduced by the intracellular Ca 2+ store depletor thapsigargin. Therefore, the intracellular Ca 2+ store is likely to contribute to the [Ca 2+ ] i transients. The [Ca 2+ ] i changes under standard ACSF and TTX showed different levels of regularity. We tested synchronization of the [Ca 2+ ] i changes between cell pairs under both conditions. The number of synchronized cell pairs was reduced in TTX. These results suggest that TTX‐insensitive and slow rate [Ca 2+ ] i changes might be involved in information processing in the striatum. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(7): 43–52, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/ecj.10242