Substance P-like immunoreactivity in the frog dorsal root ganglia.

The distribution of substance P-like immunoreactivity was studied in the thoracic dorsal root ganglia of the frog Rana esculenta by immunohistochemistry. Substance P-like immunoreactivity was contained in approximately 50% of primary sensory neurons. The immunoreactive fibers arising from the cell bodies are collected in small bundles within the ganglia neuropil before entering the central and peripheral roots.