Effect of electrical vs. chemical deep brain stimulation at midbrain sites on micturition in anaesthetized rats

Abstract

Electrical deep brain stimulation within the midbrain can inhibit reflex micturition. We suggest that the applied stimulus entrained activity in the neural circuitry locally, thereby imposing an unphysiological pattern of activity. In a way similar to the use of electrical signals to 'jam' radio transmission, this may prevent a synchronized pattern of efferent activity being transmitted to the spinal outflows to orchestrate a coordinated voiding response. Further experiments to record neuronal firing in the midbrain during the deep brain stimulation will be necessary to test this hypothesis.

Suppression of Urinary Voiding “on Demand” by High-Frequency Stimulation of the S1 Sacral Nerve Root in Anesthetized Rats

“…The present study was designed to compare the effectiveness of high‐frequency stimulation of the S1 root and the pelvic nerve to inhibit voiding. As reported previously by us and by others, continuous infusion of saline into the bladder evoked repeated voiding . In addition, we observed contraction of the external oblique musculature of the abdominal wall during voiding.…”

Glutamatergic cells in the periaqueductal gray matter mediate sensory inputs after bladder stimulation in freely moving rats

“…A number of previous studies have shown the vlPAG as the column responsible for sensorimotor communication with the bladder. [8][9][10][11][12][13] We could reproduce these findings in our experimental setting, as our data showed a significant increase in c-Fos-positive cells in this subregion after bladder stimulation. Furthermore, our results highlighted the role of glutamatergic cells in relation to bladder-PAG circuitry.…”

“…10 Chemical stimulation of the vlPAG by D,L-homocysteic acid in rats increased the frequency of micturition. 11 Stereotaxic injections of the inhibitory mediator, cobalt chloride, into the caudal vlPAG reversibly attenuated bladder contractions and external urethral sphincter electromyographic activity in rats. 12 Injection of other inhibitory or stimulatory agents, CoCl2 and L-glutamate, into the vlPAG of rats resulted in the suppression or stimulation of micturition, respectively.…”

Role of the Anterior Cingulate Cortex in the Control of Micturition Reflex in a Rat Model of Parkinson's Disease

“…The latency of PAG activation after PNL stimulation in the current study ( Figure 4A) is consistent with that (33-47 ms) reported in previous studies by Noto et al 24,25 . Thus, in contrast to the inhibitory function of the ACC, PAG is likely to have a facilitatory effect on the micturition reflex, as suggested by human brain imaging and animal studies 26,27 .…”