Electrical Stimulation Of Somatic Nerves Research Articles

Suppression of bladder overactivity by activation of somatic afferent nerves in the foot

To investigate the possibility of suppressing bladder overactivity by electrical activation of somatic afferent nerves in the foot. Cats with an intact spinal cord were studied under α-chloralose anaesthesia. Bladder pressure was recorded via a urethral catheter. Foot stimulation was applied via surface pad electrodes attached to the skin of the front or hind foot. Reflex micturition was inhibited by electrical stimulation of the hind foot at either low (5 Hz) or high (20 Hz) frequencies, but stimulation of the front foot was ineffective. The mean (sem) bladder capacity during a saline infusion cystometrogram (CMG) was significantly (P < 0.05) increased to 153.2 (18.2)% and 136.9 (14.3)% of the control bladder capacity by stimulation at frequencies of 5 Hz and 20 Hz, respectively. Intravesical infusion of 0.25% acetic acid (AA) induced bladder overactivity and reduced bladder capacity to 20.3 (8.9)% of the control capacity measured during saline infusion. Foot stimulation inhibited the AA-induced bladder overactivity recorded under isovolumetric conditions, and significantly (P < 0.05) increased bladder capacity during AA infusion. However, it only restored the small bladder capacity caused by AA irritation to 40-50% of the control bladder capacity measured during saline infusion. The effect of foot stimulation did not persist after termination of stimulation during repeated CMG tests. This study shows the potential of noninvasive transcutaneous electrical stimulation of somatic nerves in the foot to inhibit reflex bladder activity and treat overactive bladder symptoms.

Excitatory and inhibitory components of somato-sympathetic reflex

In cats anesthetized with chloralose it was confirmed that electrical stimulation of somatic nerves evoked a reflex volley (late response) followed by a transient inhibition of the spontaneous discharge (silent period) in the sympathetic postganglionic renal nerve. The thresholds for both the late response and silent period were in the same range, from 1.2 to 1.5 times the threshold for the fiber excitation in the superficial radial nerve, and from 2.5 to 3.0 times in the hamstring and sciatic nerves. The independent occurrence of the silent period from the late response was demonstrated in recovery tests. Furthermore, lesions in the dorsal surface area of the medulla oblongata selectively abolished or greatly depressed the late response, whereas lesions in the ventral medullary reticular formation selectively abolished or greatly depressed the silent period.