Age-dependent changes in the neurochemical properties of sensory neurons

Sensory neurons represent various groups of neurons differ on their morphological, immunohistochemical and receptor characteristics. The most of large neurons with myelinated Adelta fibers contain neurofilament 200 kD (NF200), some small afferent neurons can bind the isolectin B4 (IB4). Also, sensory neurons may include different types of tyrosine kinases (trkA, B and C) and neurotransmitters. Neuropeptides are generally located in small and medium-sized neurons. The proportion of neurons which contain trkA decreases and the percentage of NF200-, IB4-,substance P- and CGRP-positive neurons increases during the early development. Development of different types of sensory neurons fulfill under control of neurotrophins.