Parasympathetic neurons of salivary gland ganglia in the fetal and postnatal rat are substance P-like immunoreactive.

Substance P-like immunoreactivity (SPLI) of neuron cell bodies is described here in the parasympathetic ganglia of salivary glands in rat fetuses. When grafted to the anterior eye chamber of adult rats, outgrowth of SPLI fibers was also observed around fetal and postnatal ganglia. These observations are significant for the understanding of salivation mechanisms. They also imply the importance of substance P or related compounds in parasympathetic peripheral neurons. The graft experiments indicate a substantial morphological plasticity of these SPLI neurons on perturbation.