The developmental anatomy of the human superior hypogastric plexus: A morphometrical investigation with clinical and surgical correlations.

The superior hypogastric plexus (SHP) is the part of the autonomic nervous system, which is responsible for the sympathetic innervation of pelvic organs and extrapelvic genitals in humans of both sexes. The SHP also functions as the anatomic pathway for the major part of visceral sensitive fibers originating from pelvic viscera. In this study, the morphology of the SHP was analyzed through anatomical dissections performed both in human adult and fetal cadavers. A computerized morphometrical investigation of the SHP was also performed and the resulting quantitative data statistically assessed. The comparison between fetal and adult SHP revealed that in the male group there was a developmental increase of six times (in height) and of about five times (in width); while in the female group, there was a developmental increase of 3.5 times both in height and width values. In addition, the distance from the superior border of the SHP to the bifurcation of the common iliac arteries presented a developmental increase of about six times in the male group, and about four times in the female group. We propose an original morphological classification with six types, based upon the anatomical arrangement of the nervous fibers in this autonomic plexus.

Effects of long-term food restriction on genital reflexes in paradoxically sleep-deprived male rats.

The purpose was to ascertain whether the different schedules of long-term food restriction (FR) exert influence on genital reflexes (penile erection-PE and ejaculation-EJ) induced by paradoxical sleep deprivation (PSD) in male rats. Diet restriction began at weaning with 6 g/day and food was increased by 1 g per week until reaching 15 g/day by adulthood. Rats submitted to FR and those fed ad libitum were distributed into PSD or maintained as control groups and challenged with saline or cocaine. The results indicated that PSD+saline induced PE and EJ in both ad libitum and FR groups, but cocaine only potentiated reflexes in ad libitum group. In an attempt to revert the effects of FR on genital reflexes, we provided food ad libitum to the restricted group during the PSD period (4 days). When compared to FR rats, an increase in the frequency of PE was observed in the FR group fed ad libitum during PSD (both groups were challenged with cocaine). Further, we sought to investigate motivational behavior by placing food within the behavioral cage during the evaluation of genital reflexes. The FR PSD+saline group challenged with food did not display genital reflexes but when injected with cocaine the responses were similar to those observed in FR PSD+cocaine rats not challenged with food. Our data suggest that the facilitatory effect of PSD on genital reflexes did not override the inhibitory effect of FR on erectile function, but different schedules of FR produce distinct effects on genital reflexes. Further studies are warranted to dissect the effect of food restriction on sexual behavior.

Pro-ejaculatory effect of the aqueous crude extract of cihuapatli (Montanoa tomentosa) in spinal male rats.

In the present study, the pro-sexual effect of the cihuapatli (Montanoa tomentosa) and its possible pro-ejaculatory properties in spinal male rats were examined. Systemic administration of the aqueous crude extracts of Montanoa tomentosa exerted a pro-ejaculatory effect and produced an increase in the number of discharges in the ejaculatory motor patterns in the spinal rats. The cihuapatli-induced ejaculatory responses included the expression of penile erections and penile movements and the potent expulsion of urethral contents and in some cases the expulsion of seminal plugs. The cihuapatli-induced ejaculatory motor patterns were similar to that obtained after systemic oxytocin. Cihuapatli- and oxytocin-induced ejaculatory motor responses and the penile erections and movements were abolished by the pre-treatment with hexamethonium, a selective oxytocin antagonist. Present data show that the cihuapatli extract acts directly at the spinal system in charge of the expression of the ejaculatory motor patterns and suggest that the aqueous crude extract exerts its aphrodisiacs properties by increasing sexual potency acting as an oxytocic agent.

Conduta no trauma da genitália masculina / Procedure on male genitalia trauma

O trauma da genitália masculina tornou-se mais freqüente em ambientes de trabalho, como em indústrias, nas quais os operários sofrem acidentes com má- quinas de alta velocidade e, no ambiente urbano, devido ao grande número de acidentes automobilísticos. Estes tipos de lesões requerem hospitalização imediata, cirurgias e um suporte psicológico intenso. O objetivo deste trabalho é revisar nossa conduta nos casos de trauma de pênis e bolsa escrotal. No período de 1986 a 2003, foram atendidos 10 pacientes com lesões de genitália, no Hospital Universitário Cajuru, submetidos a cirurgias e acompanhamento pós-operatório. A conduta cirúrgica adotada variou desde o enxerto de pele ao reimplante microcirúrgico. Os pacientes foram acompanhados no pós-operatório e apresentaram uma aparência estética satisfatória e micção e função erétil normal.

The trauma of the male genitalia are frequent events in the work enviroment of industries where the high velocity machinery are responsible for this injuri- es, and in the cities with a great number of car crashes. These injuries are both physically and mentally traumatic and require hospitalization, surgeries and psychological support. The purpose of this study is to review our approach taken in injuries of the genitalia and to present our experiences. During the period of 1986 and 2003, at Hospital Universitário Cajuru, we have taken cared of ten patients with injuries in the genitalia. The surgical condut addopted varied from skin graft until reimplant. Later on during the postoperative, all the patients had an acceptable appearance and normal mictural and erectile function.

Evidence for the involvement of a spinal pattern generator in the control of the genital motor pattern of ejaculation.

One of the hypotheses to explain the neural mechanisms underlying rhythmic behaviours suggests that the central nervous system has the intrinsic capacity to produce repetitive, rhythmic output to the muscles involved in the response by means of a neuronal circuit named central pattern generator (CPG). The occurrence of rhythmic motor patterns during ejaculatory behaviour in mammals, which includes the genital motor pattern, has been shown. A CPG might regulate the timing of the repetitive muscular responses that constitute the ejaculatory motor pattern. The objective of the present study was to evidence that a CPG at a spinal level is involved in the expression and pacing of the rhythmic motor pattern generated during ejaculation. To this purpose we used the genital reflex as a model system. Following the general principles for the study of rhythmic motor patterns, the data obtained in the present series of experiments document that: (1) a rhythmic muscular response, the genital motor pattern, is registered during the ejaculatory event (expulsion of the urethral contents); (2) this ejaculatory motor response has similar EMG characteristics in intact and in spinal urethane-anaesthetised male rats; (3) interruption of the afferent inflow (deafferentation) does not disrupt the expression of the ejaculatory motor train; (4) a change in the stimulation interval does not alter the intrinsic pacing of the ejaculatory-like response; and (5) fictive ejaculation can be induced by pharmacological means. Together, this evidence supports the notion that a CPG produces the rhythmic ejaculatory motor pattern registered during fictive ejaculation.

An anatomical and electrophysiological study of the genitofemoral nerve and some of its targets in the male rat.

Anatomical descriptions of the genitofemoral nerve (GFn) innervating the lower pelvic area are contradictory. Here we re-examine its origin and innervation by its various branches of principal target organs in the male rat. Using gross dissection, electrophysiological techniques and retrograde tracing of motoneurones with horseradish peroxidase, we confirm that the GFn originates from lumbar spinal nerves 1 and 2, and that at the level of the common iliac artery it divides into a lateral femoral and a medial genital branch. In contrast to previous studies, we report that the genital and not the femoral branch innervates the abdominal-inguinal skin, and not only the genital but also the femoral branch innervates the cremaster muscle (Cm) surrounding the testes. Motoneurones innervating the Cm proper are located in the ventral nucleus of L1 and L2, and those innervating the muscular transition region of the rostral Cm are located in the ventral nucleus in L1 and the ventrolateral nucleus in L2. The GFn may contribute to male reproductive performance by transmitting cutaneous information during copulation and, via contraction of the Cm to promote ejaculation, the protective displacement of the testes into the abdominal cavity during fighting and as a sperm-protecting thermoregulatory measure.

Effects of genitofemoral nerve transection on copulatory behavior and fertility in male rats.

Selective transection of peripheral nerves that innervate the pelvic region results in the alteration of some aspects of copulatory behavior, including seminal plug weight. Both branches of the genitofemoral nerve primarily innervate the cremaster muscle although the genital branch has a wide distribution in the cremasteric sac. Thermoregulation of spermatogenesis and the mechanical event of ejaculation largely depend on cremaster contractility. In this study, we analyzed the effects of bilateral transection of the genitofemoral nerve on male copulatory behavior and on fertility. Sexually experienced adult male rats were submitted to sexual behavior tests before and after surgical transection of the genitofemoral nerve. Tests were made four times before and on Days 9, 12, 15, 18 and 21 after surgery, and seminal plug weight was also analyzed. In addition, fertility was tested using two different approaches: by allowing the male to ejaculate once in an estrous female or keeping the male with three females during 15 days. Results showed that there were no differences in any of the copulatory parameters, including seminal plug weight. Regarding fertility, both procedures showed that the ability to induce pregnancy was significantly diminished in the neurectomized males tested at different times after surgery. These results support the notion that genitofemoral nerve regulation of fertility via contraction of the male cremaster muscle is an important factor in reproduction in rats.

Muscarinic mediation of the urethro genital reflex in spinal cord-transected rats.

The effects of muscarinic receptor stimulation were tested on the urethro genital reflex (UGR) in anesthetized and spinal cord-transected rats. Drugs were applied directly to the spinal cord. The electromyographic activity (EMG) of the bulbospongiosus (BS) muscle was used for recording UGR. In six animals BS as well as soleus, posterior biceps or peroneus tertius muscle EMG was recorded simultaneously. Muscarine (5, 10, 20, 50 and 100 microg) was applied in 22 animals after cutting L6-S1 dorsal roots. Some observations were made on another six animals, to which an extensive bilateral dorsal rhizotomy (L3-S2) was performed. Rhythmic bursts of similar frequency and size to those seen during UGR were found in BS muscle a few minutes after muscarine application. No rhythmic bursting was found on the hindlimb muscles, but exclusively on BS muscles. The effects of homatropine (25, 50, 100 and 200 microg), an acetylcholine muscarinic receptor antagonist, were tested in 21 rats after UGR was elicited three times at low stimulation intensity (7 mm Hg). Homatropine produced two effects: (i) A significant increase in the latency of UGR. (ii) A facilitation of UGR inhibition. In view of these results it can be speculated that muscarinic receptor stimulation is involved in the elicitation of UGR.

Sympathetic innervation of the reproductive organs of the male opossum, Didelphis albiventris (Lund, 1841).

The dissection of nerves and ganglia anatomically related to the pelvic organs revealed one inferior mesenteric ganglion, two testicular ganglia, two hypogastric nerves, two pelvic ganglia and two pelvic nerves. The histochemical demonstration of catecholamines by a glyoxylic acid fluorescence method revealed a rich sympathetic innervation in the ductus deferens, in the three segments of the prostate and in the convoluted ductuli efferentes. The testis, epididymis and all three pairs of bulbourethral glands presented fluorescent nerve fibers only around blood vessels. Removal of the inferior mesenteric and testicular ganglia, and hypogastric neurectomy with our without ligature and sectioning of testicular arteries, had no effect on the density of the nonvascular fluorescent fibers. Removal of the periprostatic tissue caused complete denervation of the prostate and marked denervation of the ductuli efferentes and ductus deferens. Small ganglia containing fluorescent nerve cell bodies were found close to the capsule of the prostate. The results indicate that short adrenergic neurons are responsible for the sympathetic innervation of the reproductive organs of the male opossum.

Inervaçäo peptidérgica do sistema reprodutor masculino de mamíferos / Peptidergic innervation of mammalian male genitalia

O sistema reprodutor masculino dos mamíferos é ricamente inervado por fibras do sistema nervoso autônomo simpático e parassimpático. Trabalhos recentes da literatura científica descrevem a ocorrência de nervos autônomos näo-colinérgicos e näo-adrenérgicos, em que os neurotransmissores ou neuromoduladores säo polipeptídios. Os nervos peptidérgicos têm ampla ocorrência no organismo dos mamíferos, e vários deles foram observados no sistema reprodutor masculino. O presente trabalho apresenta uma revisäo da literatura científica acerca da ocorrência, distribuiçäo, origem e funçäo dos neuropeptidios na genitália masculina de mamíferos