Substance P Content in and Capsaicin-Evoked Release from Dissociated Cultures of Rat Nodose Ganglion (Vagal Sensory) Neurons

In dissociated cultures of neonatal rat nodose ganglion (vagal sensory) neurons, there is a steady net increase of 15–20 pg SP per ganglion equivalent per day. SP content but not neuron survival is enhanced by NGF. SP is released durtng exposure to 50 mmol potassium (K+) or the sensory neurotoxin, capsaicin (10 umol). These neurons in culture exhibit properties analogous to vagal sensory SP-containing neurons in vivo and may prove useful for the study of neuropeptide regulation in this visceral afferent nerve.The factors regulating the synthesis of SP in and its release from vagal sensory neurons are largely unknown. To study this regulation, we have developed cultures of neonatal nodose ganglion (NG) neurons. The cultures synthesize immunoreactive SP in amounts similar to vagal neurons in vivo and release SP in response to capsaicin (CAP), the specific sensory excitatory neurotoxin.