Evidence of vagus nerve sprouting to innervate the urinary bladder and clitoris in a canine model of lower motoneuron lesioned bladder

AIMS

Complete spinal cord injury does not block perceptual responses or inferior solitary nucleus activation after genital self-stimulation, even though the vagus is not thought to innervate pelvic structures. We tested if vagus nerve endings sprout after bladder decentralization to innervate genitourinary structures in canines with decentralized bladders.

METHODS

Four reinnervation surgeries were performed in female hounds: bilateral genitofemoral nerve transfer to pelvic nerve with vesicostomy (GNF-V) or without (GFN-NV); and left femoral nerve transfer (FNT-V and FNT-NV). After 8 months, retrograde dyes were injected into genitourinary structures. Three weeks later, at euthanasia, reinnervation was evaluated as increased detrusor pressure induced by functional electrical stimulation (FES). Controls included un-operated, sham-operated, and decentralized animals.

RESULTS

Increased detrusor pressure was seen in 8/12 GFNT-V, 4/5 GFNT-NV, 5/5 FNT-V, and 4/5 FNT-NV animals after FES, but not decentralized controls. Lumbar cord segments contained cells labeled from the bladder in all nerve transfer animals with FES-induced increased detrusor pressure. Nodose ganglia cells labeled from the bladder were observed in 5/7 nerve transfer animals (1/2 GNT-NV; 4/5 FNT-V), and from the clitoris were in 6/7 nerve transfer animals (2/2 GFNT-NV; 4/5 FNT-V). Dorsal motor nucleus vagus cells labeled from the bladder were observed in 3/5 nerve transfer animals (1/2 GFNT-NV; 2/3 FNT-V), and from the clitoris in 4/5 nerve transfer animals (1/2 GFNT-NV; 3/3 FNT-V). Controls lacked this labeling.

CONCLUSIONS

Evidence of vagal nerve sprouting to the bladder and clitoris was observed in canines with lower motoneuron lesioned bladders. Neurourol. Urodynam. 36:91-97, 2017. © 2015 Wiley Periodicals, Inc.

Assessing traumatic brain injuries using EEG power spectral analysis and instantaneous phase

Although mild traumatic brain injury (mTBI) occurs commonly, little is known about how multiple mTBI incidents accumulate over time to produce serious morbidity or how the extent of injury can be quantified. This work presents a rat model that uses deceleration-induced brain trauma and an implantable EEG system for recording injury-induced changes in brain activity. Specifically, we present an analysis method to assess and quantify mTBI by combining information derived from EEG power spectral analysis and EEG phase shifts. We found that in different frequency bands, both EEG power spectra and the instantaneous phases of the two EEG channels before the impact were different from those measured after the impact. This study shows that EEG analysis can be used as a tool to identify and assess brain related injuries.

Different effects on bone strength and cell differentiation in pre pubertal caloric restriction versus hypothalamic suppression

Hypothalamic amenorrhea and energy restriction during puberty affect peak bone mass accrual. One hypothesis suggests energy restriction alters hypothalamic function resulting in suppressed estradiol levels leading to bone loss. However, both positive and negative results have been reported regarding energy restriction and bone strength. Therefore, the purpose of this study was to investigate energy restriction and hypothalamic suppression during pubertal onset on bone mechanical strength and the osteogenic capacity of bone marrow-derived cells in two models: female rats treated with gonadotropin releasing hormone antagonists (GnRH-a) or 30% energy restriction. At 23 days of age, female Sprague Dawley rats were assigned to three groups: control group (C, n=10), GnRH-a group (n=10), and Energy Restriction (ER, n=12) group. GnRH-a animals received daily injections for 27 days. The animals in the ER group received 70% of the control animals' intake. After sacrifice (50 days of age), body weight, uterine and muscle weights were measured. Bone marrow-derived stromal cells were cultured and assayed for proliferation and differentiation into osteoblasts. Outcome measures included bone strength, bone histomorphometry and architecture, serum IGF-1 and osteocalcin. GnRH-a suppressed uterine weight, decreased osteoblast proliferation, bone strength, trabecular bone volume and architecture compared to control. Elevated serum IGF-1 and osteocalcin levels and body weight were found. The ER model had an increase in osteoblast proliferation compared to the GnRH-a group, similar bone strength relative to body weight and increased trabecular bone volume in the lumbar spine compared to control. The ER animals were smaller but had developed bone strength sufficient for their size. In contrast, suppressed estradiol via hypothalamic suppression resulted in bone strength deficits and trabecular bone volume loss. In summary, our results support the hypothesis that during periods of nutritional stress the increased vertebral bone volume may be an adaptive mechanism to store mineral which differs from suppressed estradiol resulting from hypothalamic suppression.

[Secondary rupture of the spleen after external cardiac massage]

A case of delayed splenic rupture occurring 18 days after external cardiac massage is reported. A 30 year old woman underwent mitral valve replacement. Two cardiac arrests in the immediate postoperative period were successfully treated by external cardiac massage. Recovery was uneventful until the 18th day, when the patient began to suffer from dizziness. Haemodynamic and biological data suggested hypovolaemia by dehydration. The day after, her abdomen became painful and anaemia was discovered. Splenic rupture was diagnosed by abdominal ultrasonography and splenectomy was carried out; no other lesion was found. In spite of the widespread practice of external cardiac massage, splenic rupture without any other lesion is unusual. It is suggested that abdominal ultrasonography should follow all cardiac massages.