Objectives: The aim was to determine whether somatic afferent fiber stimulation influences thoracic spinal neuronal activity responding to gastric distensions.
Materials and methods: Extracellular potentials of single T9-T10 spinal neurons were recorded in anesthetized male rats. Ipsilateral median and peroneal nerve afferent stimulation (MNAS, PNAS) was delivered by electrodes. Inflation of a latex balloon was used to produce gastric distension.
Results: MNAS and PNAS (1.5 mA, 50 Hz, 10 sec) altered activity of 63% and 66% of the spinal neurons excited or inhibited by gastric distension, respectively. MNAS more frequently reduced spinal neuronal activity with excitatory responses to gastric distension than did PNAS (p < 0.05). PNAS more likely increased neuronal activity with low-threshold excitatory responses to gastric distension than MNAS (p < 0.05).
Conclusions: Peripheral somatic afferent information utilizes central pathways to modulate gastric afferent processing in T9-T10 spinal neurons. Thus, somatic afferent stimulation might be used to treat gastric pain and/or hypersensitivity.
© 2009 International Neuromodulation Society.