Small Ganglion Research Articles

Morphological Peculiarities of the Pelvic Autonomic Nervous System and Their Impact on Clinical Interventions in the Lesser Pelvic Region.

Background: The aim of the work is to define the morphological peculiarities of the pelvic autonomic nervous system (ANS) and their importance in the clinical and surgical interventions in the lesser pelvis. Material and methods: Anatomical variations in the formation of the pelvic ANS were observed in 20 cadavers. The study included 17 men (85%), aged 18 to 84, and 3 women, aged 27 to 86. The average age was 53.8 years. The subjects most often died by violent death in car accidents, by asphyxia, or by sudden death. The study was approved by the Ethics Committee of the Health Care Surveillance Authority, Bratislava, Slovakia. We studied cadavers without congenital or detected anomalies, cancer, deformities of the body, or spinal or abdominal surgeries within 24 h of death. We observed a relationship between the dimensions and the number of ganglia, as well as the number and course of nerve branches and anastomoses. In the pelvic area, we observed the hypogastric plexus superior, hypogastric plexus inferior, and the truncus sympathicus. In all cadavers, we clarified the lumbosacral plexuses after evisceration. In the lumbosacral region, the roots were defined based on their participation in the formation of the plexuses. To show the intimate relationship between both systems, we also focused on the details of the structure (rami communicantes) related to the connections of the ANS with the spinal nervous system. Results: Anatomical variations in the formation of the pelvic ANS were observed in all cases. We included cases with more than two truncus sympathicus ganglia as the segmental type. The segmental form occurred in 14 (70%) cases, and was concentrated in 6 (30%) cases. Rami communicantes provided anastomoses to the spinal nerves. Small ganglia were observed on the rami communicantes. With the concentrated type, we observed the division of the sympathetic and parasympathetic systems. With the segmental and concentrated forms, symptoms of the "diffuse form" may occur, which we observed in all cases. We observed significant right-left asymmetry and differences in the formation of ganglia and anastomoses. Conclusions: This study allowed us to identify and describe the morphological peculiarities of the pelvic ANS and their possible influence on the clinical picture. Asymmetry and dependence of their occurrence on the type of ANS was observed. The variations were frequent. Their preoperative diagnosis is difficult to impossible. The absence or lack of intraoperative vigilance can lead to the damage of pelvic ANS during operations and blockades of the pelvic plexus. The acquired knowledge can be helpful in clarifying clinical signs and symptoms of these conditions.

Effects of microfracture parameters on adaptive pumping in fractured porous media: Pore-scale simulation

Adaptive pumping, exchanging injection and extraction well locations, has achieved good performance in many subsurface operations such as enhanced oil recovery, CO2 sequestration, and aquifer contaminant remediation. However, the pore-scale flow mechanism behind this phenomenon and the effect of fractures on it are poorly understood. In this study, the phase field method is used to trace the interface evolution in the matrix with different fracture parameters, such as width, length, orientation angle, and tortuosity. The results show that the presence of fractures converts the flow regime from continuous pathway flow (CPF) to ganglion dynamics (GD), which improves the transfer kinetics of the displacing fluid. Fracture width and tortuosity significantly affect the ultimate displacement efficiency in positive pumping, while the orientation angle has the most significant effect in adaptive pumping. The disintegration of the residual displaced fluid into smaller ganglia is the displacement mechanism of adaptive pumping, but it is suppressed in fractured porous media. The adaptive pumping reaches the maximum displacement efficiency when the fracture is vertical to the flow direction, which is 15.12% higher than that of the positive pumping in the non-fractured model. These results can bridge the cognitive gap between micro- and macro-phenomena and guide practical engineering.

Identification of cranial nerve ganglia using sectioned images and three-dimensional models of a cadaver.

BackgroundCranial nerve ganglia, which are prone to viral infections and tumors, are located deep in the head, so their detailed anatomy is difficult to understand using conventional cadaver dissection. For locating the small ganglia in medical images, their sectional anatomy should be learned by medical students and doctors. The purpose of this study is to elucidate cranial ganglia anatomy using sectioned images and three-dimensional (3D) models of a cadaver.MethodsOne thousand two hundred and forty-six sectioned images of a male cadaver were examined to identify the cranial nerve ganglia. Using the real color sectioned images, real color volume model having a voxel size of 0.4 × 0.4 × 0.4 mm was produced.ResultsThe sectioned images and 3D models can be downloaded for free from a webpage, anatomy.dongguk.ac.kr/ganglia. On the images and model, all the cranial nerve ganglia and their whole course were identified. In case of the facial nerve, the geniculate, pterygopalatine, and submandibular ganglia were clearly identified. In case of the glossopharyngeal nerve, the superior, inferior, and otic ganglia were found. Thanks to the high resolution and real color of the sectioned images and volume models, detailed observation of the ganglia was possible. Since the volume models can be cut both in orthogonal planes and oblique planes, advanced sectional anatomy of the ganglia can be explained concretely.ConclusionsThe sectioned images and 3D models will be helpful resources for understanding cranial nerve ganglia anatomy, for performing related surgical procedures.

Dispersal and immunohistochemical characteristics of neurons in the stem of the porcine vagus nerve.

The present study investigated the distribution and chemical properties of nerve cell bodies within the trunk of the vagus nerve in juvenile female pigs (n=4) using double-labelling immunofluorescence. The neurons appeared mostly as single cells or formed streaks of cells or small ganglia. Many of the perikarya were cholinergic (VAChT-positive; VAChT+) or adrenergic (DβH+) in nature and no SP+ or CGRP+ neurons were encountered. There were no distinct left-right differences regarding the number and chemical coding of the neuronal somata, however, these characteristics significantly varied between particular nerve segments investigated. The vagosympathetic trunks, and thoracic and abdominal segments of the vagus nerve contained on average (the numerical values represent the means for both the left and right corresponding nerve segments) 142, 236, and 111 PGP 9.5-positive neurons, respectively. Proportions of cholinergic and adrenergic neurons were as follows: 0% and 100%, 54.2% and 33.2%, and 52.8% and 35.4%, respectively. Relatively many neurons in the thoracic and abdominal segments stained also for NOS (39.2% and 39.9%, respectively). It remains to be determined whether the porcine intravagal neurons represent a developmental relic, or whether they have any specific functional significance.

Loss of Elp1 disrupts trigeminal ganglion neurodevelopment in a model of familial dysautonomia.

Familial dysautonomia (FD) is a sensory and autonomic neuropathy caused by mutations in elongator complex protein 1 (ELP1). FD patients have small trigeminal nerves and impaired facial pain and temperature perception. These signals are relayed by nociceptive neurons in the trigeminal ganglion, a structure that is composed of both neural crest- and placode-derived cells. Mice lacking Elp1 in neural crest derivatives ('Elp1 CKO') are born with small trigeminal ganglia, suggesting Elp1 is important for trigeminal ganglion development, yet the function of Elp1 in this context is unknown. We demonstrate that Elp1, expressed in both neural crest- and placode-derived neurons, is not required for initial trigeminal ganglion formation. However, Elp1 CKO trigeminal neurons exhibit abnormal axon outgrowth and deficient target innervation. Developing nociceptors expressing the receptor TrkA undergo early apoptosis in Elp1 CKO, while TrkB- and TrkC-expressing neurons are spared, indicating Elp1 supports the target innervation and survival of trigeminal nociceptors. Furthermore, we demonstrate that specific TrkA deficits in the Elp1 CKO trigeminal ganglion reflect the neural crest lineage of most TrkA neurons versus the placodal lineage of most TrkB and TrkC neurons. Altogether, these findings explain defects in cranial gangliogenesis that may lead to loss of facial pain and temperature sensation in FD.

Cervicothoracic sympathetic system in the dog: new insights by the gross morphological description of each ganglion with its branches on each side.

Much published data exists on the position of cervicothoracic ganglion, but a little published research has been done on the cervicothoracic system of dog. Herein, we illustrated topographical position and shape of each ganglion of cervicothoracic system to determine the distribution of nerves dispersing from them on two sides, left and right. Our work designed on the usage of 10 healthy adult dogs. Left cervicothoracic sympathetic system is represented by two ganglia: caudal and middle ganglion, while the right system is represented by three ganglia: caudal, middle cervical and small accessory ganglia. Left caudal cervical ganglion was elongated triangular, while the right one was elongated spindle in shape. Left caudal cervical ganglion was located on lateral surface of longus colli muscle, at the first intercostal space, while the right one was located at the level of the second rib. Left middle cervical ganglion was ovoid in shape and located at the first intercostal space, while the right one was located at the level of the second rib. There were two nerve trunks forming ansa subclavian trunk on both sides. There were three sympathetic-parasympathetic communicating branches on both sides. Our study recorded the first observation of left pericardial branch in dog, which originated from the caudal angle of middle cervical ganglion. There was a small ganglion located on the lateral surface of trachea at the level of the first rib.

Rhythmicity in the Enteric Nervous System of Mice.

The enteric nervous system (ENS) is required for many cyclical patterns of motor activity along different regions of the gastrointestinal (GI) tract. What has remained mysterious is precisely how many thousands of neurons within the ENS are temporally activated to generate cyclical neurogenic contractions of GI-smooth muscle layers. This has been an especially puzzling conundrum, since the ENS consists of an extensive network of small ganglia, with each ganglion consisting of a heterogeneous population of neurons, with diverse cell soma morphologies, neurochemical and biophysical characteristics, and neural connectivity. Neuronal imaging studies of the mouse large intestine have provided major new insights into how the different classes of myenteric neurons are activated during cyclical neurogenic motor patterns, such as the colonic motor complex (CMC). It has been revealed that during CMCs (in the isolated mouse whole colon), large populations of myenteric neurons, across large spatial fields, coordinate their firing, via bursts of fast synaptic inputs at ~2 Hz. This coordinated firing of many thousands of myenteric neurons synchronously over many rows of interconnected ganglia occurs irrespective of the functional class of neuron. Aborally directed propulsion of content along the mouse colon is due, in large part, to polarity of the enteric circuits including the projections of the intrinsic excitatory and inhibitory motor neurons but still involves the fundamental ~2 Hz rhythmic activity of specific classes of enteric neurons. What remains to be determined are the mechanisms that initiate and terminate the patterned firing of large ensembles of enteric neurons during cyclic activity. This remains an exciting challenge for future studies.

Enteric nervous system and inflammatory bowel diseases: Correlated impacts and therapeutic approaches through the P2X7 receptor.

The enteric nervous system (ENS) consists of thousands of small ganglia arranged in the submucosal and myenteric plexuses, which can be negatively affected by Crohn’s disease and ulcerative colitis - inflammatory bowel diseases (IBDs). IBDs are complex and multifactorial disorders characterized by chronic and recurrent inflammation of the intestine, and the symptoms of IBDs may include abdominal pain, diarrhea, rectal bleeding, and weight loss. The P2X7 receptor has become a promising therapeutic target for IBDs, especially owing to its wide expression and, in the case of other purinergic receptors, in both human and model animal enteric cells. However, little is known about the actual involvement between the activation of the P2X7 receptor and the cascade of subsequent events and how all these activities associated with chemical signals interfere with the functionality of the affected or treated intestine. In this review, an integrated view is provided, correlating the structural organization of the ENS and the effects of IBDs, focusing on cellular constituents and how therapeutic approaches through the P2X7 receptor can assist in both protection from damage and tissue preservation.

Comparison of the curative effect and prognosis of stereotactic drainage and conservative treatment for moderate and small basal ganglia haemorrhage

BackgroundMinimally invasive surgery has achieved good results in the treatment of cerebral haemorrhage.However, no large-scale clinical study has demonstrated that surgical treatment of cerebral haemorrhages less than 30 ml can improve the curative effect. Our study explored the efficacy and complication of stereotactic drainage based on the amount of cerebral hemorrhage (15-30 ml) in hypertensive basal ganglia.MethodSixty patients with hypertensive basal ganglia haemorrhages were divided into a control group and an experimental group with 30 patients in each group. Patients in the control group were treated conservatively. In contrast, those in the experimental group received stereotactic drainage, and urokinase was injected into the haematoma cavity after the operation. The haematoma volume at admission and 1, 3, 7 and 30 days after treatment and National Institute of Health stroke scale(NIHSS) score data were recorded. Complications after treatment in the two groups of data were compared and analysed.ResultNo significant differences in age, sex, time of treatment after onset, admission blood pressure, admission haematoma volume or admission NIHSS score were noted between these two groups (P > 0.05). After treatment, significant differences in haematoma volume were noted between the two groups on the 1st, 3rd, 7th and 30th days after treatment (P < 0.05). The amount of hematoma of patients in the experimental group was significantly reduced compared with that in the control group, and the NIHSS scores were significantly different on the 3rd, 7th and 30th days after treatment. The neurological deficit scores of patients in the experimental group were significantly reduced compared with those in the control group, and the incidence of pulmonary infection and venous thrombosis in the lower limbs of patients in the experimental group were significantly reduced (P < 0.05). ROC curve analysis showed that stereotactic drainage affected the early neurological function of patients with small and medium basal ganglia haemorrhages.ConclusionFor patients with small and medium basal ganglia haemorrhages, stereotactic drainage can be used due to the faster drainage speed of haematomas after operation, which is beneficial to the recovery of neurological function and reduce complications.

Direct Numerical Simulation of Pore-Scale Trapping Events During Capillary-Dominated Two-Phase Flow in Porous Media

This study focuses on direct numerical simulation of imbibition, displacement of the non-wetting phase by the wetting phase, through water-wet carbonate rocks. We simulate multiphase flow in a limestone and compare our results with high-resolution synchrotron X-ray images of displacement previously published in the literature by Singh et al. (Sci Rep 7:5192, 2017). We use the results to interpret the observed displacement events that cannot be described using conventional metrics such as pore-to-throat aspect ratio. We show that the complex geometry of porous media can dictate a curvature balance that prevents snap-off from happening in spite of favourable large aspect ratios. We also show that pinned fluid-fluid-solid contact lines can lead to snap-off of small ganglia on pore walls; we propose that this pinning is caused by sub-resolution roughness on scales of less than a micron. Our numerical results show that even in water-wet porous media, we need to allow pinned contacts in place to reproduce experimental results.

Pan-enteric neuropathy and dysmotility are present in a mouse model of short-segment Hirschsprung disease and may contribute to post-pullthrough morbidity

PurposeHirschsprung disease (HSCR) is characterized by distal intestinal aganglionosis. While surgery is lifesaving, gastrointestinal (GI) motility disorders persist in many patients. Our objective was to determine whether enteric nervous system (ENS) abnormalities exist in the ganglionated portions of the GI tract far proximal to the aganglionic region and whether these are associated with GI dysmotility. MethodsUsing Ednrb-null mice, a model of HSCR, immunohistochemical analysis was performed to evaluate quantitatively ENS structure in proximal colon, small intestine, and stomach. Gastric emptying and intestinal transit were measured in vivo and small and large bowel contractility was assessed by spatiotemporal mapping ex vivo. ResultsProximal colon of HSCR mice had smaller ganglia and decreased neuronal fiber density, along with a marked reduction in migrating motor complexes. The distal small intestine exhibited significantly fewer ganglia and decreased neuronal fiber density, and this was associated with delayed small intestinal transit time. Finally, in the stomach of HSCR mice, enteric neuronal packing density was increased and gastric emptying was faster. ConclusionsENS abnormalities and motility defects are present throughout the ganglionated portions of the GI tract in Ednrb-deficient mice. This may explain the GI morbidity that often occurs following pull-through surgery for HSCR.

Cholinergic and adrenergic innervation of the pancreas in chinchilla (Chinchilla Laniger Molina).

Cholinergic and adrenergic innervation of the pancreas in chinchilla (Chinchilla Laniger Molina) was examined in this study. The pancreas is both an exocrine and endocrine gland with autonomic and sensory innervation presented by the numerous nerve fibers and small agglomerations of nerve cells. Investigations were performed on 16 adult chinchillas of both sexes. The material was collected immediately after death of the animals. Histochemical methods: AChE and SPG were used, in addition to routine technique of single and double immunohistochemical (IHC) staining using whole mount specimens and freezing sections with a thickness of 8 to 12 μm. In the immunofluorescence staining, primary antibodies directed against markers used to identify cholinergic - ChAT and VAChT, and adrenergic - DbH and TH neurons. Secondary antibodies were coupled to Alexa Fluor 488 and Alexa Fluor 555 fluorophores. Histochemical studies (AChE) revealed that chinchilla pancreatic cholinergic innervation consisted of ganglionic neurocytes and numerous nerve fibers. These structures are located in the parenchyma of the exocrine part of the organ in close proximity to blood vessels and are present within the walls of the pancreatic ducts and interstitial connective tissue. A delicate fiber network around the Langerhans islets was also observed. The most numerous cholinergic structures were found in the head and tail, and the least numbers were found in the body of the pancreas. The SPG method revealed that adrenergic fibers form a network in the adventitia of blood vessels, and individual fibers run throughout the pancreatic parenchyma. Moreover, adrenergic nerve fibers were observed around the ganglionic neurocytes. This innervation was similar in all parts of the investigated organ. IHC investigations allowed observations of both the cholinergic and adrenergic activities of autonomic nerve structures. Additionally, using ChAT/DbH double staining, colocalization of these substances was observed in the fibers of the pancreatic parenchyma that passed through the cholinergic ganglia. Colocalization of VAChT and TH was found in nerve fibers of the exocrine part, in the walls of blood vessels, and in individual nerve cells. Colocalization of ChAT/DbH and VAChT/TH was observed in the single nerve cells and in the small (2-3 cell) ganglia. ChAT- and DbH-immunopositive nerve fibers were found in the area of the islets of Langerhans. The results indicate a more intense cholinergic innervation of the chinchilla's pancreas, which is represented by both ganglia and nerve fibers, while adrenergic structures are mainly represented by fibers and only single neurocytes. This arrangement of the investigated structures in this species may imply a major role for hormonal control of exocrine secretion in rodents.

The Zebrafish Heart: an Archetype for Neurocardiology

The intracardiac nervous system (ICNS) is the final common pathway for reflex control of cardiac output by the autonomic nervous system (ANS). The normal operation of this system is key to supporting cardiovascular homeostasis, and ANS dysfunction or remodelling can contribute to the development of multiple cardiopathies. Thus the role of the ICNS in cardiac control is essential, however our current understanding of this role is incomplete. The majority of work on the ICNS to date has been in mammalian models, but because the neural elements comprising this network are embedded in cardiac tissues, visualization and experimental access to the entire network for integrative studies of neuronal function has been limiting. To address these issues, we have developed the zebrafish, a cyprinid teleost, as an alternate model for cardiac anatomical and neurophysiological studies. In this ancestral vertebrate the two‐chambered heart, although anatomically distinct from the mammalian four chamber arrangement, is dually innervated by sympathetic and parasympathetic limbs of the ANS and has a well‐developed ICNS which is functional in spontaneously beating isolated preparations. Activation of extrinsic cardiac nerves evokes tachycardia (via B2‐adrenoceptors) and bradycardia (M2 muscarinic receptors). Thus the essential features of ANS control of the heart are conserved across the vertebrates. We have mapped the general innervation patterns of the sinoatrial valve region (SAR), atrium and ventricle. A ganglionated plexus in the SAR surrounds the valve and contains most of the intracardiac neuronal somata; the majority is cholinergic with the remainder adrenergic, nitrergic and serotonergic. Furthermore, peptidergic axon terminals contact plexal somata. Optical mapping of the isolated heart confirms the site of origin of normal primary pacemaker activity within the SAR, where cells in the base of the valve leaflets express Islet‐1 (Isl‐1) and hyperpolarization‐activated, cyclic nucleotide‐gated channel 4 (HCN4), known markers for mammalian pacemaker cells. In addition, intracellular recordings from these cells display spontaneous diastolic membrane depolarization patterns typical of pacemaker cells. Extrinsic cardiac nerve stimulation, in addition to evoking bradycardia, can displace the pacemaker site to a secondary pacemaker in the atrioventricular region (AVR), where a population of cells also expresses Isl‐1 and HCN4. A small ganglion containing cholinergic somata is present in the AVR, suggesting local neural control of atrioventricular pacemaker activity. We have thus established the zebrafish heart as a viable model for studies of integrative neural control of pacemaker function. In particular, this model provides a platform to use optogenetic techniques to target intracardiac neurons and pacemaker cells, in combination with traditional electrophysiological methods, to perform detailed analyses of the intracardiac neuronal circuitry involved in cardiac control. This work will provide a solid foundation for further studies of ANS‐related cardiac pathophysiologies in zebrafish analogs of human cardiac disease states.Support or Funding InformationNatural Sciences and Engineering Research Council of Canada (FMS, TAQ, RPC)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

(235) Homeostatic Regulation of Intrinsic Plasticity in Peripheral Nociceptors

Stabilization of neuronal activity is crucial for normal nervous system regulation. When changes in the environment chronically alter neuronal activity, homeostatic plasticity creates compensatory shifts (i.e., regulation of intrinsic excitability) to return the system to a physiological level. This plasticity helps prevent circuits from becoming either hyper- or hypoexcitable. Despite this protective mechanism, evidence suggests that the development and maintenance of many chronic pain conditions depend on chronically altered sensory afferent activity. This led us to consider the possibility that malfunction of homeostatic mechanisms may contribute to chronic pain. Since homeostatic plasticity has been primarily studied in the central nervous system, we first tested whether this plasticity also occurs in peripheral nociceptors [i.e., small diameter dorsal root ganglia (DRG) sensory afferent neurons]. We hypothesized that mouse and human primary sensory afferents undergo homeostatic regulation of intrinsic plasticity, evidenced by compensatory changes in neuronal excitability in response to chronic stimuli. Using a combination of pharmacologic and optogenetic approaches with whole-cell electrophysiology, we previously presented that sustained, 24-hour KCl depolarization of dissociated mouse and human DRG neurons led to a compensatory decrease in excitability of small diameter cells. This suggested that putative nociceptors undergo homeostatic regulation of intrinsic excitability. In an effort to demonstrate bidirectionality of this homeostatic plasticity, in this study we used a 24-hour incubation with lidocaine and TTX. We found no change in excitability, likely due to the already quiescent nature of DRG neurons in vitro. Ongoing experiments are being performed to determine whether mechanisms of this plasticity are altered in vivo and during chronic pain. This work was supported by grants R01 NS042595 (RG) and T32DA007261 (LM).

Method for Detecting Hyaluronan in Isolated Myenteric Plexus Ganglia of Adult Rat Small Intestine.

The cellular components of the enteric nervous system (ENS), namely enteric neurons and glia, display plasticity and respond to environmental cues deriving from growth factors, extracellular matrix (ECM) molecules, and cell-surface molecules, both in physiological and pathological conditions. ECM, in particular, provides an important framework for the enteric microenvironment and influences the homeostasis of myenteric neuronal circuitries. Isolation of pure myenteric plexus preparations from adult tissue permits to investigate changes in the ENS involving specific ECM, such as hyaluronan. This approach is based upon the possibility to isolate myenteric ganglia from the intestinal wall of either adult animals or humans, after microdissection and subsequent enzymatic digestion of the tissue. Enteric ganglia are free of connective tissue, extracellular collagen, and blood vessels, and thus treatment of intact intestinal segments with highly purified collagenases permits ganglia isolation from the surrounding smooth muscle cells. In this chapter, we describe methods for visualizing HA in isolated primary cultures of adult rat small intestine myenteric ganglia.

Subserosal localization of myenteric ganglia in normal human appendix: immunostaining with neuronal and glial markers.

Visualization of unexpected distribution of myenteric ganglia in normal human appendiceal wall by immunofluorescence. The myenteric plexus is located between the longitudinal and circular muscle layers of the GIT. However, recently the irregular distribution of myenteric ganglia was revealed in human appendix. The cryosections prepared from normal human appendices were examined by immunofluorescence methods using antibodies to neurofilaments (NF) and glial fibrillary acidic protein (GFAP). Indirect immunofluorescence revealed the positive staining of myenteric ganglia with both neuronal and glial marker antibodies. Double labeling for NF/GFAP staining showed close assotiation between glia and neurons inside ganglia. GFAP-positive cells were often observed as the cells surrounding myenteric ganglia. The staining confirmed the irregular distribution of myenteric ganglia in human appendiceal wall and revealed the small ganglia in the subserosal area. Our results showed that localization of myenteric ganglia in human appendix differs from other parts of GIT. GFAP immunostaining is available for visualization of smaller myenteric ganglia located mainly in the subserosal area. Our studies may find application in current HIV research focused on enteric neuropathogenesis and in diagnostic laparoscopy for chronic abdominal pain: to detect the irritation of subserosal ganglia (Fig. 2, Ref. 26).

Nervus terminalis and nerves to the vomeronasal organ: a study using human fetal specimens.

The human nervus terminalis (terminal nerve) and the nerves to the vomeronasal organ (VNON) are both associated with the olfactory nerves and are of major interest to embryologists. However, there is still limited knowledge on their topographical anatomy in the nasal septum and on the number and distribution of ganglion cells along and near the cribriform plate of the ethmoid bone. We observed serial or semiserial sections of 30 fetuses at 7–18 weeks (crown rump length [CRL], 25–160 mm). Calretinin and S100 protein staining demonstrated not only the terminal nerve along the anterior edge of the perpendicular lamina of the ethmoid, but also the VNON along the posterior edge of the lamina. The terminal nerve was composed of 1–2 nerve bundles that passed through the anterior end of the cribriform plate, whereas the VNON consisted of 2–3 bundles behind the olfactory nerves. The terminal nerve ran along and crossed the posterior side of the nasal branch of the anterior ethmoidal nerve. Multiple clusters of small ganglion cells were found on the lateral surfaces of the ethmoid's crista galli, which are likely the origin of both the terminal nerve and VNON. The ganglions along the crista galli were ball-like and 15–20 µm in diameter and, ranged from 40–153 in unilateral number according to our counting at 21-µm-interval except for one specimen (480 neurons; CRL, 137 mm). An effect of nerve degeneration with increasing age seemed to be masked by a remarkable individual difference.

Neuromuscular structure of the larva to early ancestrula stages of the cyclostome bryozoan Crisia eburnea

AbstractFor the first time, the development of a cyclostome bryozoan has been studied with immunochemistry and confocal laser scanning microscopy, with emphasis on nerves and muscles. The larva is covered by multiciliated cells, which are latitudinally strongly elongated and show phalloidin‐stained cell junctions. We hypothesize that these cells contract at metamorphosis and squeeze the apical invagination and the adhesive sac out. Ectodermal, longitudinal muscle cells extend from the cells of the inner, conical cuticularized part of the apical invagination to the lower part of the corona, around the adhesive sac pore. These muscles are retained in the ancestrula. Scattered monociliated nerve cells are interspersed between the coronal ciliary cells. An equatorial nerve in the larva disappears at metamorphosis. The central, conical part of the cuticle becomes the terminal membrane of the ancestrula, and the underlying ectodermal and mesodermal cell layers differentiate into the polypide bud, forming a deep narrow invagination, differentiating into vestibule–atrium, mouth ring and pharynx–stomach–rectum. Tentacles develop from the ring of cells around the mouth, and a small ganglion with four nerves innervating each of the tentacles develops at the anal side of the mouth. These new findings yield further support for previous homology statements of bryozoan larvae and development.

Morphological and neurochemical differences in peptidergic nerve fibers of the mouse vagina.

The vagina is innervated by a complex arrangement of sensory, sympathetic, and parasympathetic nerve fibers that contain classical transmitters plus an array of neuropeptides and enzymes known to regulate diverse processes including blood flow and nociception. The neurochemical characteristics and distributions of peptide-containing nerves in the mouse vagina are unknown. This study used multiple labeling immunohistochemistry, confocal maging and analysis to investigate the presence and colocalization of the peptides vasoactive intestinal polypeptide (VIP), calcitonin-gene related peptide (CGRP), substance P (SP), neuropeptide tyrosine (NPY), and the nitric oxide synthesizing enzyme neuronal nitric oxide synthase (nNOS) in nerve fibers of the murine vaginal wall. We compared cervical and vulvar areas of the vagina in young nullipara and older multipara C57Bl/6 mice, and identified differences including that small ganglia were restricted to cervical segments, epithelial fibers were mainly present in vulvar segments and most nerve fibers were found in the lamina propria of the cervical region of the vagina, where a higher number of fibers containing immunoreactivity for VIP, CGRP, SP, or nNOS were found. Two populations of VIP-containing fibers were identified: fibers containing CGRP and fibers containing VIP but not CGRP. Differences between young and older mice were present in multiple layers of the vaginal wall, with older mice showing overall loss of innervation of epithelium of the proximal vagina and reduced proportions of VIP, CGRP, and SP containing nerve fibers in the distal epithelium. The distal vagina also showed increased vascularization and perivascular fibers containing NPY. Immunolabeling of ganglia associated with the vagina indicated the likely origin of some peptidergic fibers. Our results reveal regional differences and age- or parity-related changes in innervation of the mouse vagina, effecting the distribution of neuropeptides with diverse roles in function of the female genital tract.

Octodon degus, a new model to study the agonist and plexus-induced response in the urinary bladder

Urinary bladder function consists in the storage and controlled voiding of urine. Translational studies require animal models that match human characteristics, such as Octodon degus, a diurnal rodent. This study aims to characterize the contractility of the detrusor muscle and the morphology and code of the vesical plexus from O. degus. Body temperature was measured by an intra-abdominal sensor, the contractility of detrusor strips was evaluated by isometric tension recording, and the vesical plexus was studied by electrical field stimulation (EFS) and immunofluorescence. The animals showed a diurnal chronotype as judged from core temperature. The myogenic contractile response of the detrusor muscle to increasing doses of KCl reached its maximum (31.04mN/mm2) at 60mM. In the case of cumulative dose-response of bethanecol, the maximum response (37.42mN/mm2) was reached at 3.2×10-4M. The response to ATP was clearly smaller (3.8mN/mm2). The pharmacological dissection of the EFS-induced contraction identified ACh and sensory fibers as the main contributors to this response. The neurons of the vesical plexus were located mainly in the trigone area, grouped in big and small ganglia. Out of them, 48.1% of the neurons were nitrergic and 62.7% cholinergic. Our results show functional and morphological similarities between the urinary bladder of O. degus and that of humans.