Neurones and glial cells of the mouse sciatic nerve undergo apoptosis after injury in vivo and in vitro.

Analogous to the death of developing neurones deprived of trophic factors, nerve injury in adult life could lead to nerve cell death by apoptosis. Here the occurrence of apoptotic mouse sciatic sensory neurones after injury was investigated by nick-labelling DNA breaks. A small proportion of the neurones reliably became apoptotic after injury in vivo. The response was strongly amplified when the nerves were injured in vitro, where Ca(2+)-chelation and protein synthesis inhibition were effective in inhibiting apoptosis. In addition to nerve cells, both Schwann cells and satellite cells became apoptotic after injury. Apoptosis in cultured mouse sciatic nerves appears advantageous for the identification of survival factors acting on adult peripheral neurones.