Effects of low-intensity extracorporeal shock wave on bladder and urethral dysfunction in spinal cord injured rats.

PURPOSE: To investigate the effects of low-intensity extracorporeal shock wave therapy (LiESWT) on bladder and urethral dysfunction with detrusor overactivity and detrusor sphincter dyssynergia (DSD) resulting from spinal cord injury (SCI). METHODS: At 3 weeks after Th9 spinal cord transection, LiESWT was performed on the bladder and urethra of adult female Sprague Dawley rats with 300 shots of 2 Hz and an energy flux density of 0.12 mJ/mm2, repeated four times every 3 days, totaling 1200 shots. Six weeks postoperatively, a single cystometrogram (CMG) and an external urethral sphincter electromyogram (EUS-EMG) were simultaneously recorded in awake animals, followed by histological evaluation. RESULTS: Voiding efficiency significantly improved in the LiESWT group (71.2%) compared to that in the control group (51.8%). The reduced EUS activity ratio during voiding (duration of reduced EUS activity during voiding/EUS contraction duration with voiding + duration of reduced EUS activity during voiding) was significantly higher in the LiESWT group (66.9%) compared to the control group (46.3%). Immunohistochemical examination revealed that fibrosis in the urethral muscle layer was reduced, and S-100 stained-positive area, a Schwann cell marker, was significantly increased in the urethra of the LiESWT group. CONCLUSION: LiESWT targeting the urethra after SCI can restore the EUS-EMG tonic activity during voiding, thereby partially ameliorating DSD. Therefore, LiESWT is a promising approach for treating bladder and urethral dysfunction following SCI.

Effects of low-intensity extracorporeal shock wave therapy on lipopolysaccharide cystitis in a rat model of interstitial cystitis/bladder pain syndrome.

PURPOSE: To investigate the effect of low-intensity extracorporeal shock wave therapy (LiESWT) on lipopolysaccharide (LPS)-induced cystitis in an animal model of interstitial cystitis/bladder pain syndrome (IC/BPS). METHODS: Sprague-Dawley rats were divided into three groups: control, cystitis (LPS group, intravesical injection of LPS (1 mg) twice), and cystitis with LiESWT (LiESWT group). On the third and fourth days, LiESWT was administered (0.12 mJ/mm2, 300 shots each time) on the lower abdomen toward the bladder. On the seventh day, the rats underwent pain assessment and a metabolic cage study. Subsequently, a continuous cystometrogram (CMG) was performed under urethane anaesthesia. Immunohistochemical studies were also performed, including S-100 staining, an immunohistochemical marker of Schwann cells in the bladder. RESULTS: In the LPS group, the pain threshold in the lower abdomen was significantly lower than that in the control group. In the metabolic cage study, the mean voided volume in the LPS group significantly increased. The CMG also revealed a significant decrease in bladder contraction amplitude, compatible with detrusor underactivity in the LPS group. Immunohistochemical studies showed inflammatory changes in the submucosa, increased fibrosis, and decreased S-100 stain-positive areas in the muscle layer of the LPS group. In the LiESWT group, tactile allodynia and bladder function were ameliorated, and S-100 stain-positive areas were increased. CONCLUSION: By restoring nerve damage, LiESWT improved lower abdominal pain sensitivity and bladder function in an LPS-induced cystitis rat model. This study suggests that LiESWT may be a new therapeutic modality for IC/BPS.

Influence of cerebral infarction on both bladder and urethral activities and changes after tramadol administration in rats.

AIMS: We investigated the changes in bladder and urethral function after cerebral infarction (CI) and the influence of tramadol on these functions. METHODS: Twenty-eight female Sprague Dawley rats were divided into normal and CI groups. In the awake condition, metabolic cage study and blood pressure were evaluated. Under urethane anesthesia, the intravenous effect of tramadol (0.01-1 mg/kg), which has both µ-opioid receptor stimulation and inhibition of norepinephrine and serotonin reuptake, on continuous cystometry, and simultaneous measurements of bladder and urethral perfusion pressure (UPP) were recorded. Infarcted lesions were examined by staining with triphenyltetrazolium chloride, a marker of mitochondrial enzyme activity. RESULTS: CI rats showed impaired sympathetic activity with Horner's syndrome and lower blood pressure. In metabolic cage study, urinary frequency during the dark phase was increased in CI rats. On bladder activity, in CI rats, the baseline pressure threshold for inducing bladder contractions was significantly lower (p < 0.01), and the intercontraction interval was prolonged after tramadol administration. On urethral activity, the baseline UPP was significantly lower in CI rats than in normal rats and it did not change after tramadol administration. Residual urine rate was significantly increased in normal rats, but not in CI rats. CI rats showed brain infarction including the cortex and hypothalamus, which is a center of the autonomic nervous system. CONCLUSIONS: CI-induced ischemic brain damage results in impairment of both bladder and urethral functions, in addition to decreased sympathetic activity. Bladder overactivity after CI can be improved by tramadol; however, urethral activity cannot be improved by it.

Evaluation of the Influence of a History of Childhood Nocturnal Enuresis on Nighttime Urinary Frequency and the Causes of Nocturia in Adults.

OBJECTIVE: To examine whether a history of nocturnal enuresis affects nighttime urinary frequency and to evaluate nocturia etiologies in adults. MATERIALS AND METHODS: A total of 143 participants with at least one episode of nocturia per night were included in this study. The self-reported questionnaire collected data on demographic characteristics, medical history, history of nocturnal enuresis in elementary school, lower urinary tract symptoms, and frequency-volume charts. RESULTS: A history of nocturnal enuresis was observed in 52.4% of participants. However, night-time urinary frequency was significantly lower in participants with a history of nocturnal enuresis in elementary school than in those without such history. On multivariate analysis, a history of nocturnal enuresis was also negatively associated with nighttime urinary frequency (P <.01). There was a collinearity effect between age and nighttime urinary frequency. A history of nocturnal enuresis did not affect the presence of nocturnal polyuria or overactive bladder in participants. However, sleep disturbances were fewer in participants with a history of nocturnal enuresis (odds ratio 0.404). CONCLUSION: A history of nocturnal enuresis might be negatively associated with nighttime urinary frequency due to fewer sleep disturbances. Further, progression of nocturia may depend on conditions, such as age and acquired diseases.

Spatial information enhanced by non-spatial information in hippocampal granule cells.

The hippocampus organizes sequential memory composed of non-spatial information (such as objects and odors) and spatial information (places). The dentate gyrus (DG) in the hippocampus receives two types of information from the lateral and medial entorhinal cortices. Non-spatial and spatial information is delivered respectively to distal and medial dendrites (MDs) of granule cells (GCs) within the molecular layer in the DG. To investigate the role of the association of those two inputs, we measured the response characteristics of distal and MDs of a GC in a rat hippocampal slice and developed a multi-compartment GC model with dynamic synapses; this model reproduces the response characteristics of the dendrites. Upon applying random inputs or input sequences generated by a Markov process to the computational model, it was found that a high-frequency random pulse input to distal dendrites (DDs) and, separately, regular burst inputs to MDs were effective for inducing GC activation. Furthermore, when the random and theta burst inputs were simultaneously applied to the respective dendrites, the pattern discrimination for theta burst input to MDs that caused slight GC activation was enhanced in the presence of random input to DDs. These results suggest that the temporal pattern discrimination of spatial information is originally involved in a synaptic characteristic in GCs and is enhanced by non-spatial information input to DDs. Consequently, the co-activation of two separate inputs may play a crucial role in the information processing on dendrites of GCs by usefully combing each temporal sequence.

Input integration around the dendritic branches in hippocampal dentate granule cells.

Recent studies have shown that the dendrites of several neurons are not simple translators but are crucial facilitators of excitatory postsynaptic potential (EPSP) propagation and summation of synaptic inputs to compensate for inherent voltage attenuation. Granule cells (GCs)are located at the gateway for valuable information arriving at the hippocampus from the entorhinal cortex. However, the underlying mechanisms of information integration along the dendrites of GCs in the hippocampus are still unclear. In this study, we investigated the input integration around dendritic branches of GCs in the rat hippocampus. We applied differential spatiotemporal stimulations to the dendrites using a high-speed glutamate-uncaging laser. Our results showed that when two sites close to and equidistant from a branching point were simultaneously stimulated, a nonlinear summation of EPSPs was observed at the soma. In addition, nonlinear summation (facilitation) depended on the stimulus location and was significantly blocked by the application of a voltage-dependent Ca(2+) channel antagonist. These findings suggest that the nonlinear summation of EPSPs around the dendritic branches of hippocampal GCs is a result of voltage-dependent Ca(2+) channel activation and may play a crucial role in the integration of input information.