Age-related features in expression of calcium-binding proteins in autonomic ganglionic neurons

Abstract

Calbindin 28 kDa (CB), calretinin (CR), and parvalbumin (PB) are calcium-binding proteins that are widely distributed in the nervous system and selectively expressed in certain population of neurons. These proteins are expressed not only in the central nervous system but also the autonomic ganglia. CB and PB are found in the sympathetic ganglia of rodents, and CB and CR are found in metasympathetic intramural ganglia. Their functions are poorly understood, but one can suggest that they have an important role in the regulation of Ca²⁺ levels in the cell. Calcium-binding proteins also play an important role in the age-related development of autonomic neurons. The percentage of CB- and CR-immunopositive neurons in the metasympathetic intramural ganglia of the small intestine in early postnatal development increases, whereas the percentage of CB decreases in sympathetic ganglia. It is possible that the functional meaning of such changes may be associated with the role of calcium currents in the development of neurons and the synaptic transmission.