[Neuralgia of the genitofemoral nerve after hernioplasty. Therapy by peripheral nerve stimulation]. / Neuralgie des N. genitofemoralis nach Hernioplastik. Therapie durch periphere Nervenstimulation.

The peripheral nerve stimulation (PNS) is an established therapy in the management of neuropathic pain. Here, we describe a case of successful epifascial stimulation in the proximity of the genitofemoral nerve, which was injured during an endoscopic hernioplasty. During the following months the patient developed an intense neuropathy of this nerve, which we now treated by permanent PNS with an 8-polar electrode. During the 1 year follow-up the patient described a pain reduction of nearly 70%. There were no adverse events until now. In conclusion, PNS is a promising procedure in the treatment of neuralgia after hernioplasty.

Role played by brainstem neurons in regulating testosterone secretion via a direct neural pathway between the hypothalamus and the testes.

We previously reported anatomical and functional evidence for a direct, inhibitory neural pathway that regulates testosterone (T) secretion independently of the pituitary. This pathway is activated by the intracerebroventricular (icv) administration of agents that stimulate stress responses, such as IL-1beta, corticotropin-releasing factor (CRF), and norepinephrine (NE), which results in a blunted T response to the administration of human chorionic gonadotropin (hCG). Blunting of the T response is mediated by central beta-adrenergic receptor stimulation. CRF, but not ethanol (EtOH) or IL-1beta, acts directly on the paraventricular nucleus of the hypothalamus to activate the pathway. Here we explored the role played by brain areas hypothesized to be part of this pathway, such as neurons in the dorsal pons [including the locus coeruleus (LC) of the brainstem], where NE is produced. Microinfusion of EtOH or IL-1beta, but not CRF, into these neurons activated the pathway. Electrolytic lesions of this region significantly reversed the inhibitory effect of icv-administered EtOH on hCG-induced T release, while having no effect on the ability of IL-1beta or CRF to do so. However, the icv administration of IL-1beta, EtOH, or CRF, in doses that rapidly inhibit the T response to hCG, all caused a significant depletion of NE from the LC. Collectively, these results indicate that in addition to the paraventricular nucleus, the brainstem area containing the LC is part of a neural pathway that connects the brain to the testes independently of the pituitary. We also speculate that EtOH may stimulate this pathway through NE-dependent activation of the dorsal pons.

A hypothalamic-testicular neural pathway is influenced by brain catecholamines, but not testicular blood flow.

We previously reported the existence of a descending multisynaptic, pituitary-independent, neural pathway between the hypothalamus and the testes in the male rat. Stimulation of this pathway by the intracerebroventricular (icv) injection of IL-1beta or corticotropin-releasing factor blunts the testosterone (T) response to human chorionic gonadotropin (hCG). This response is mediated at least in part by catecholamine beta-adrenergic receptor activation. The present work was performed to further investigate the role of brain catecholamines and testicular blood flow in this pathway. The icv injection of 5 microl of 200 proof ethanol (EtOH; 86 micromol) did not result in detectable levels of the drug in the general circulation and did not induce neuronal damage, but rapidly blunted hCG-induced T release while not decreasing LH levels or altering testicular blood flow. EtOH significantly up-regulated transcripts of the immediate-early gene c-fos in the paraventricular nucleus (PVN) of the hypothalamus. Lesions of the PVN blocked the inhibitory effect of IL-1beta on T, but only partially interfered with the influence of EtOH. PVN catecholamine turnover significantly increased after icv injection of IL-1beta, but not EtOH. Brain catecholamine depletion due to the neurotoxin 6-hydroxydopamine did not alter the ability of hCG to induce T release, but significantly reversed the inhibitory effect of icv EtOH or IL-1beta on this response. Collectively, these results indicate that icv-injected IL-1beta or EtOH blunts hCG-induced T secretion through a catecholamine-mediated mechanism that does not depend on either peripherally mediated effects or pituitary LH, and that the PVN plays a role in these effects.

Capsaicin in albino rats prevents contralateral testis from the damaging effects posed by ipsilateral testis that underwent torsion.

OBJECTIVE: To evaluate the effect of capsaicin, a powerful neurotoxin selective to afferent nerves, on contralateral testicular damage in ipsilateral testicular torsion. METHODS: Forty male albino rats were randomly allocated into five groups. No operation was performed in group one. After intraperitoneal administration of 0.9% NaCl, rats underwent a sham operation in group 2 and testicular torsion in group 3. In groups 4 and 5 rats underwent sham operation and testicular torsion, respectively after intraoperitoneal capsaicin injection. Contralateral testes were harvested on the fifteenth day of the experiment and mean seminiferous tubular diameters and mean testicular biopsy scores were recorded for each testis. The values were compared through analysis of variance (ANOVA) with Turkey-Kramer multiple comparisons test and p values less than 0.05 were considered to be significant. RESULTS: Mean testicular biopsy scores and mean seminiferous tubular diameters of group 5 was significantly higher than the group 3. There was no difference between the groups 1, 2, 4, and 5 when these two parameters are concerned. CONCLUSION: Capsaicin effectively prevents contralateral testicular damage encountered following ipsilateral testicular torsion. The inhibition of afferent impulses from the ipsilateral testis under distress prevents contralateral testicular injury, and provides additional data to support the role of an autonomic reflex arc in contralateral testicular injury.

Static magnetic field therapy for pain in the abdomen and genitals.

Two adolescents with debilitating, medication-resistant, chronic pain of the low back and abdomen with intermittent pain of the genitalia were diagnosed with intervertebral disk disease at spinal cord levels that correlated with their signs. Both patients had undergone multiple evaluations by physicians of different specialties and both underwent appendectomy without relief of their pain. The history of the onset of pain was important in determining the affected levels. The pain of both individuals was mimicked and localized by percussion of the vertebral spines at the level of disk protrusion. This maneuver and careful review of the history were important in making the correct diagnosis in each case. In both patients, treatment with novel magnetic devices provided rapid relief that was sustained for more than 2 years. These cases highlight the need for careful evaluation and correct diagnosis of abdominal and genital pain in young patients to avoid costly and unnecessary medical intervention and the stigma of painful debility.

Induction of multiple pituitary adenylate cyclase activating polypeptide (PACAP) transcripts through alternative cleavage and polyadenylation of proPACAP precursor mRNA.

Many regulated events guide neuropeptide biosynthesis, processing, and secretion. For PACAP peptides, these events have not been well examined. In our studies of PACAP expression in sympathetic neurons, we discovered that neuronal depolarization not only increased the levels of the 2.2 kb form of proPACAP mRNA identified in neuronal tissues, but also induced a novel 0.9 kb PACAP transcript, which appeared similar in size to a form present in testes. Using reverse-transcription PCR and 3' RACE studies, we demonstrated that the 0.9 kb PACAP mRNA in depolarized SCG neurons was not identical to the testicular PACAP mRNA, but represented shortened, more stable, forms of the 2.2 kb transcript resulting from alternative upstream polyadenylation site usage. These results demonstrate that post-transcriptional mechanisms play important roles in determining cellular PACAP levels and provide several important insights. For example, alternative upstream polyadenylation can elicit a major influence on the amount of bioactive peptide that can by synthesized, since short 3' UTR transcripts are usually more stable due to elimination of destabilizing elements present in the longer messages. In cells such as testicular germ cells, which have restricted transcriptional periods, stable mRNAs allow longer translational events and extended periods of peptide production. The neuronal PACAP system adopts a similar post-transcriptional strategy following neuronal depolarization, and although the roles of PACAP remain unclear, this suggests important roles for PACAP peptides during increased neuronal activity. Additionally, unlike alternative polyadenylation described for many genes, alternative site usage in the proPACAP transcript does not result from alternative splicing. The mechanism of alternative site usage may be related to changes in the expression and binding of polyadenylation factors to the short and long 3' UTR proPACAP sites leading to production of more stable transcripts and increased PACAP precursor biosynthesis. The implications of increased PACAP production following altered neurophysiological states and the mechanisms underlying alternative polyadenylation site choice are important considerations for future inquiries.

Lesions in the bed nucleus of the stria terminalis, but not in the lateral septum, inhibit short-photoperiod-induced testicular regression in Syrian hamsters.

The transfer of adult male hamsters from long days (LD) to short days (SD) (i.e. < 12 h of light per day) typically results in marked testicular regression and a decline in plasma testosterone concentrations. To help disclose key brain regions responsible for mediating this photoperiodic response male hamsters received either chemical (i.e. N-methyl-D-aspartate; NMDA) or radiofrequency current lesions in the bed nucleus of the stria terminalis (BNST), and were then exposed to SD for 15 or 12 weeks, respectively. Although body weights were similar between sham-lesioned controls and the NMDA-lesioned hamsters, the latter showed a significant attenuation of testicular regression; additionally, their plasma testosterone concentrations remained at typical LD levels. When radiofrequency current-lesioned hamsters were transferred from LD to SD they also failed to show significant signs of testicular regression, nor a decline in plasma testosterone concentrations, nor a complete arrest of spermatogenesis. In contrast, sham-lesioned controls or hamsters that were lesioned dorsally to the BNST at a site primarily involving the lateral septum all showed the expected degree of testicular regression, a decline in plasma testosterone concentrations, and complete arrest of spermatogenesis; body weights were similar in all of the experimental group. Taken together, these findings suggest that the BNST, a brain area traditionally not associated with reproductive function, may play an important role in mediating photoperiodic information to the neural circuits that control the reproductive axis.

Short-term effects of vasoligation upon plasma follicle-stimulating hormone, luteinizing hormone, and prolactin in the adult rat: further evidence for a direct neural connection between the testes and the central nervous system.

The purpose of these experiments was to determine whether bilateral vasoligation of adult male rats had any short-term effects upon plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin. Adult male rats (250-300 g) were either bilaterally vasoligated or sham vasoligated, and blood samples were obtained by cardiac puncture preoperatively and at 24 h and 7 days following surgery. Plasma levels of both FSH and LH were significantly (P less than 0.01) decreased at 24 h following vasoligation compared to preoperative levels and those of sham-operated controls. However, the response was differential since, at 7 days following vasoligation, plasma FSH was still significantly decreased while LH was returning to control levels. Conversely, plasma prolactin levels were significantly (P less than 0.01) increased at 24 h compared to preoperative values and those in sham-operated controls, and at 7 days prolactin had returned to preoperative control levels. Sham vasoligation did not significantly change plasma levels of FSH, LH, or prolactin at any of the time intervals investigated. These results provide further evidence that suggests that there may be a direct connection between the testis and central nervous system that may be involved in the short-term regulation of gonadotropin and prolactin secretion.

Effect of unilateral orchidectomy on plasma FSH concentration: evidence for a direct neural connection between testes and CNS.

The effect of unilateral orchidectomy on plasma FSH, LH and LHRH content in the right and left half of the median eminence-arcuate nucleus region was examined in adult rats. Following right-sided orchidectomy, plasma FSH began to rise but a significant increase was not observed until 1 week after the operation. No significant changes were observed in LH values. LHRH content in the ipsilateral median eminence-arcuate region showed a significant increase only when the median eminence was removed together with the arcuate nucleus, but not when it was removed separately, which suggests that the increase in LHRH content was attributable to an increased LHRH content of the ipsilateral arcuate nucleus. Radiofrequency lesions placed unilaterally in the same side of the dorsal anterior hypothalamic area as the hemiorchidectomy partially blocked the selective FSH release following unilateral orchidectomy, while contralateral or sham lesions had no effect. These results suggest that the gonad has a direct neural connection with the hypothalamus, which is involved in selective FSH release following hemiorchidectomy.

Effect of electrical stimulation of the testis on the nucleus praeopticus pars magnocellularis of the frog, Rana tigrina.

The changes in the nucleus praeopticus (NPO) pars magnocellularis of the frog Rana tigrina were studied after electrical stimulation of the left testis. After a 3-min stimulation, the neurones of the nucleus showed a statistically significant increase in the nuclear and cellular diameters. The lateral neurones in particular showed a complete loss of Nissl substance and other acute chromatolytic changes. In the aldehyde fuchsin stained preparations, however, the perikarya appeared filled with clumps of intensely stained neurosecretory material (NSM) and disintegrating cell nuclei. The NSM was discharged in the axons, resulting in an increase in number and size of the Herring bodies. These changes were abolished in frogs whose testes had been pre-anaesthetized with xylocaine. Based on these observations, the possible existence of an afferent pathway from the testis to the NPO pars magnocellularis is suggested.