Developmental pattern of calbindin D28k protein expression in the rat striatum and cerebral cortex.

We examined the protein expression of the calcium-binding protein calbindin D28k in two developing rat brain structures, the striatum and the cerebral cortex. The relative protein concentration level was quantified by means of the Western blotting method and densitometric scanning. 32 Wistar rats were used, divided according to survival period (P0-P120-postnatal days). Observations of the calbindin D28k protein expression in the rat striatum and the cerebral cortex revealed an increase in band color intensity between P0 and P10. The intensity of protein staining in older groups of animals stabilised at a similar level and in the P28 and P120 groups we observed a decrement of calbindin expression in the striatum. Calbindin D28k stabilises the intracellular calcium level, preventing calcium-induced apoptotic cell death in neurons. Thus, changes in calbindin D28k expression might be related to its neuroprotective role in differentiation and synaptogenesis during the postnatal development of the brain.