Immunohistochemical localization of neurocalcin in human sensory neurons and mechanoreceptors

The localization of neurocalcin in the developing and adult human periphera l nervous system (dorsal root and sympathetic ganglia (DRG, SG), and enteri c nervous system (ENS)) was investigated using immunohistochemistry. A subp opulation of large-sized neurons in DRG of 9 and 12 weeks old embryos showe d immunoreactivity (IR), whereas the sympathetic ganglia or enteric neurons did not. In adults, neurocalcin IR was restricted to a subpopulation of la rge (13%) and intermediate (15%) sized neurons in DRG. The protein was also found in muscular (67%) and cutaneous (12%) nerve fibers, as well as in th e axons supplying muscular (muscle spindles, Golgi's tendon organs, and per imysial Pacinian corpuscles) and cutaneous (Meissner's but not Pacinian cor puscles) mechanoreceptors, as well as motor end-plates. Present results dem onstrate that neurocalcin in both developing and adult humans can be used a s a specific marker for a subpopulation of sensory neurons coupled to propr ioception and touch, and for axons of motoneurons forming motor end-plates. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.