Members of the family of
calcium binding proteins (CBPs) are involved in the buffering of
calcium (Ca2+) by regulating how Ca2+ can operate within synapses or more globally in the entire cytoplasm and they are present in a particular arrangement in all types of retinal neurons.
Calbindin D28k and
calretinin belong to the family of CBPs and they are mainly co-expressed with other CBPs.
Calbindin D28k is expressed in doubles cones, bipolar cells and in a subpopulation of amacrine and
ganglion neurons.
Calretinin is present in horizontal cells as well as in a subpopulation of amacrine and
ganglion neurons. Both
proteins fill the
soma at the inner nuclear layer and the neuronal projections at the inner plexiform layer. Moreover,
calbindin D28k and
calretinin have been associated with neuronal plasticity in the central nervous system. During pre and early postnatal visual development, the visual system shows high responsiveness to environmental influences. In this work we observed modifications in the pattern of stratification of
calbindin immunoreactive neurons, as well as in the total amount of
calbindin through the early postnatal development. In order to test whether or not
calbindin is involved in
retinal plasticity we analyzed phosphorylated
p38 MAPK expression, which showed a decrease in p-p38 MAPK, concomitant to the observed decrease of
calbindin D28k. Results showed in this study suggest that
calbindin is a molecule related with neuroplasticity, and we suggest that
calbindin D28k has significant roles in neuroplastic changes in the retina, when retinas are stimulated with different light conditions.