Dorsal Bodies Research Articles

Dorsal Fixation of Coronal Hamate and Fifth Metacarpal Base Fractures: An Anatomic Evaluation of the Ulnar Nerve

Traumatic drill overshoot during dorsal fixation of coronal hamate and fifth metacarpal base fractures risks iatrogenic ulnar nerve injury. This study describes the anatomic relationships between exiting volar drill tips and ulnar nerve branches. Dorsal drilling of hamate bones and fifth metacarpal bases was performed on cadavers. Dorsal hamate bodies were subdivided into 4 quadrants: (1) distal-ulnar, (2) distal-radial, (3) proximal-ulnar, and (4) proximal-radial. Screws measuring 5 mm more than the dorsal-to-volar bone depths were placed in each quadrant to represent drill exit trajectories with consistent overshoot. A single screw was similarly placed 5 mm distal to the midline articular surface of the dorsal fifth metacarpal base. Distances between estimated drill tips and ulnar nerve branches were measured. Ten cadaver hands were examined. The fifth metacarpal base screw tips directly abutted the ulnar motor branch in 6 hands, and were within 1 mm in 4 hands (mean, 0.4 ± 0.5 mm). Distances from the tips to the ulnar motor and sensory branches were largest in the distal-radial quadrant (11.8 ± 0.8 mm and 9.2 ± 1.9 mm, respectively) and smallest in the proximal-ulnar quadrant (7.3 ± 1.5 mm and 4.3 ± 1.1 mm, respectively). Distances to the ulnar motor and sensory branches were similar between the proximal-ulnar and distal-ulnar quadrants, and between the proximal-radial and distal-radial quadrants. Dorsal drilling of coronal hamate fractures appears to be safe, as volar drill tips are well away from ulnar nerve motor and sensory branches. Distances to ulnar nerve branches are largest, and theoretically safest, with dorsal drilling in the distal-radial hamate. Dorsal drilling of fifth metacarpal base fractures appears to carry a high risk for potential ulnar motor nerve injury. These findings may help minimize potential risks for iatrogenic ulnar nerve injury with dorsal drilling of hamate and fifth metacarpal base fractures.

Progressive pseudo-rheumatoid dysplasia -a rare genetic disorder: Case Report

Progressive pseudorheumatoid dysplasia (PPRD), also known as spondyloepiphyseal dysplasia tarda with progressive arthropathy (SEDT-PA), is an autosomal recessive disorder, resulting from mutations in the WNT1-inducible signaling pathway protein 3 (WISP3) gene involving the axial skeleton as well as small peripheral joints. Because of rarity here we present a case of 14-year-old boy, 1st issue of consanguineous parents who was presented with pain & gradual development of contracture in 3rd distal interphalangeal joint of right hand when he was 4-year-old, then gradual involvement of other interphalangeal joints of hands, bilateral wrists, elbows, shoulder, knees &ankles occurred over years with the development of contractures and restricted movement. For last few years, he developed difficulty in walking. Clinically spinal scoliosis and coxa vara was present. Mobility of spines and multiple joints including proximal & distal interphalangeal joints of hands, wrists, elbows, shoulders, knees, ankles were restricted with flexion contractures. The gait of the patient was limping. Radiological evaluation showed osteopenia in X-ray of pelvis with both hip joints and both knee joints. Generalized osteopenia, fusiform swelling in distal interphalangeal joint, flexion deformity in distal interphalangeal joint of middle and ring fingers of both hand was shown in X-ray of both hands. MRI of lumbosacral spine showed dorso-lumbar vertebral bodies dysplastic with anterior wedging producing bullet nose. Superior epiphyseal deformity was also noted in lower dorsal bodies suggestive of spondyloepiphyseal dysplasia of dorso-lumbar spine. Genetic study showed homozygous nonsense variation in exon 5 of the WISP3 gene suggestive pathogenic variant. Finally, he was diagnosed as a case of PPRD and treated with physiotherapy, family counseling, and anti-inflammatory medications.
 AKMMC J 2022; 13(1) : 52-55

Action potential alterations induced by single F11 neuronal cell loading

Several research programmes have demonstrated how Transcranial Ultrasound Stimulation (TUS) can non-invasively and reversibly mechanically perturb neuronal functions. However, the mechanisms through which such reversible and a priori non-damaging behaviour can be observed remain largely unknown. While several TUS protocols have demonstrated motor and behavioural alterations in in vivo models, in vitro studies remain scarce. In particular, an experimental framework able to load mechanically an individual neuron in a controlled manner and simultaneously measure the generation and evolution of action potentials before, during and after such load, while allowing for direct microscopy, has not been successfully proposed. To this end, we herein present a multiphysics setup combining nanoindentation and patch clamp systems, assembled in an inverted microscope for simultaneous bright-field or fluorescence imaging. We evaluate the potential of the platform with a set of experiments in which single dorsal root ganglion-derived neuronal cell bodies are compressed while their spontaneous activity is recorded. We show that these transient quasi-static mechanical loads reversibly affect the amplitude and rate of change of the neuronal action potentials, which are smaller and slower upon indentation, while irreversibly altering other features. The ability to simultaneously image, mechanically and electrically manipulate and record single cells in a perturbed mechanical environment makes this system particularly suitable for studying the multiphysics of the brain at the cell level.

C-Jun/p38MAPK/ASIC3 pathways specifically activated by nerve growth factor through TrkA are crucial for mechanical allodynia development.

Mechanical allodynia is a cardinal sign of several inflammatory pain disorders where nerve growth factor, a prototypic neurotrophin, plays a crucial role by binding to TrkA receptors. Here, we took the advantage of our generated knock-in mouse model expressing a chimeric TrkA/TrkC receptor that seems to not specifically develop mechanical allodynia after inflammation, to identify the TrkA downstream pathways involved in this phenomenon. We confirmed and extended that disrupting TrkA-specific pathways leads to a specific deficit in mechanical hypersensitivity development after somatic (systemic nerve growth factor administration and paw incision) and, to a lesser extent, visceral injuries. Despite a deficit in thin, mainly peptidergic, fibre innervation in TrkAC mice, thermal hyperalgesia development was not different from WT mice. Inflammatory reaction (oedema, IL-6 content), pain behaviours after intraplantar capsaicin, as well as TRPV1 calcium imaging response of dorsal root ganglion neurons were similar between TrkAC and WT mice. This deficiency in mechanical allodynia development in TrkAC mice is likely due to the alteration of the expression of different TrkA transduction pathways (ie, Akt, p38 MAPK, and c-Jun) especially p38 MAPK, in the dorsal root ganglion cell bodies, ultimately leading to an alteration of at least, ASIC3 channel overexpression, known to participate in nociceptor mechanosensory function.

Multiple myeloma of young adult presented with paraplegia, rare case report in Saudi Arabia.

Multiple myeloma is the second most common hematologic malignancy. It is characterized by the neoplastic proliferation of plasma cells in the bone marrow, leading to excessive production of monoclonal immunoglobulin. The mean age at diagnosis is 65 years. There are only a few cases of Multiple Myeloma arising in young population reported in the literature. We present a case of 33-years-old male presented with complete bilateral lower limbs paralysis and loss of sensation which were gradual in onset and accompanied by upper and lower back pain for 1 month. MRI of the whole spine show multiple infiltrative bone marrow high signal in T2 and STIR sequences involve C4 and the upper dorsal vertebral bodies and the spinous process of D4 with left para-spinal and large posterior epidural mass compress the spinal cord. CT guidance obtains three samples from the mass and placed in formalin in separate containers. Histopathology examination revealed neoplastic growth composed of Sheet of diffuse atypical plasma cells infiltrating fibro collagenous and adipose tissue. Although Multiple myeloma is a disease of elderly; it still could present in young age group. Histopathology examination is the gold standard for diagnosis.

Co‐localization of Isolectin B4 (IB4), Ionized Calcium‐Binding Adapter Molecule 1 (Iba1), and Von Willebrand Factor (vWF) Immunostaining in the Mid‐Cervical Spinal Cord After Spinal Injury

IB4 immunostaining is often used to histologically identify thin fiber non‐peptidergic afferent neurons in the spinal cord. However, IB4 can also identify both endothelial cells and microglia. In studies of adult Sprague Dawley rats with chronic (12 weeks) cervical (C2) hemisection injury (Hx; N=10), we noted robust IB4 immunostaining in mid‐cervical dorsal root ganglia cell bodies as well as spinal cord lamina II, indicating labeling of thin fiber afferents. We also observed distinct clusters of IB4+ cells in the mid‐cervical spinal cord ipsilateral to Hx in the area of the corticospinal tract (N=6 of 10 rats), and in ventrolateral (N=9 of 10) and ventromedial white matter (N=9 of 10). Incubation of tissues with primary antibodies for both IB4 and Iba1 (which can label activated microglia) revealed clear co‐localization of staining in these regions. Spinal intact rats (N=5) had robust IB4 staining in lamina II, but staining was not observed in the corticospinal tract, or ventrolateral or ventromedial white matter. The IB4‐Iba1 co‐localization after Hx likely indicates neuroinflammation and degeneration of damaged tracts. We also observed that IB4 immunostaining broadly dispersed throughout white and gray matter, in a pattern consistent with blood vessel endothelium labeling. To verify this, tissues were co‐incubated with primary antibodies against IB4 and vWF, a marker of endothelial cells. Co‐localization of vWF and IB4 immunostaining was detected throughout the mid‐cervical cord, and IB4 staining intensity was decreased in ventral gray matter caudal to Hx (P<0.05 vs. spinal intact). Reduction of IB4 intensity is consistent with vascular damage and regional tissue hypoxia. We conclude that following chronic C2Hx in adult rats, immunostaining with IB4 can identify blood vessel endothelial cells and activated microglia.Support or Funding Information1R01HL139708‐01A1 (DDF), OT2 OD023854, T32‐HD043730 (MDS), K99 HL143207‐01 (KS).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Two new species of Psolus Oken from Brazil (Holothuroidea: Psolidae),with neotype designation and redescription of Psolus vitoriae Tommasi, 1971, and a key to the southwestern Atlantic and Magellanic species.

The taxonomy of the southeastern Brazilian species of Psolus is reviewed and two new species described. Additionally, P. vitoriae is redescribed based on a newly designated neotype and supplemental material from the type locality and nearby regions. The synonymy of P. marcusi with P. patagonicus is called into question. The calcareous ring is useful for distinguishing between some Psolus species. Psolus tommasi sp. nov. is characterized by having five oral valves, an anus covered by a variable number of small, irregular anal valves, oral and anal valves distinct from body wall scales, calcareous ring interradial plates entire, calcareous ring simple, without posterior processes; radial and interradial plates entire, dorsal ossicles spheroid bodies and sole ossicles knobbed and smooth perforated plates. Psolus thandari sp. nov. is characterized by granules on body scales; mouth surrounded by five to seven triangular valves of equal size; anus surrounded by a variable number of small and irregular anal valves that grade into surrounding scales; calcareous ring with interradial plates entire. Six species of Psolus are known from the southwestern Atlantic and Magellanic region: P. vitoriae (São Paulo, Brazil); P. patagonicus (Mar del Plata to Tierra del Fuego, Argentina; Strait of Magellan and Cape Horn); P. segregatus (Patagonia, Argentina; Strait of Magellan, Chile; Hikurangi Margin and Chatham Rise, New Zealand); P. antarcticus (Magellanic region; South Georgia Island, southern Atlantic Ocean; Macquarie Island and Ridge, New Zealand); P. lawrencei (Mar del Plata, Argentina) and Psolus murrayi Théel, 1886 (Montevideo, Uruguay). A key to the species of Psolus from the southwestern Atlantic and Magellanic region, and a synoptic table to all southern Atlantic Psolus species is provided.

Promoting the Outgrowth of Neurites on Electrospun Microfibers by Functionalization with Electrosprayed Microparticles of Fatty Acids

AbstractControlling the outgrowth of neurites is important for enhancing the repair of injured nerves and understanding the development of nervous systems. Herein we report a simple strategy for enhancing the outgrowth of neurites through a unique integration of topographical guidance and a chemical cue. We use electrospray to easily functionalize the surface of a substrate with microparticles of natural fatty acids at a controllable density. Through a synergistic effect from the surface roughness arising from the microparticles and the chemical cue offered by the fatty acids, the outgrowth of neurites from PC12 cells is greatly enhanced. We also functionalize the surfaces of uniaxially aligned, electrospun microfibers with the microparticles and further demonstrate that the substrates can guide and enhance directional outgrowth of neurites from both PC12 multicellular spheroids and chick embryonic dorsal root ganglia bodies.

Promoting the Outgrowth of Neurites on Electrospun Microfibers by Functionalization with Electrosprayed Microparticles of Fatty Acids.

Controlling the outgrowth of neurites is important for enhancing the repair of injured nerves and understanding the development of nervous systems. Herein we report a simple strategy for enhancing the outgrowth of neurites through a unique integration of topographical guidance and a chemical cue. We use electrospray to easily functionalize the surface of a substrate with microparticles of natural fatty acids at a controllable density. Through a synergistic effect from the surface roughness arising from the microparticles and the chemical cue offered by the fatty acids, the outgrowth of neurites from PC12 cells is greatly enhanced. We also functionalize the surfaces of uniaxially aligned, electrospun microfibers with the microparticles and further demonstrate that the substrates can guide and enhance directional outgrowth of neurites from both PC12 multicellular spheroids and chick embryonic dorsal root ganglia bodies.

Identification of the most significant magnetic resonance imaging (MRI) radiomic features in oncological patients with vertebral bone marrow metastatic disease: a feasibility study.

Recently, radiomic analysis has gained attention as a valuable instrument for the management of oncological patients. The aim of the study is to isolate which features of magnetic resonance imaging (MRI)-based radiomic analysis have to be considered the most significant predictors of metastasis in oncological patients with spinal bone marrow metastatic disease. Eight oncological patients (3 lung cancer; 1 prostatic cancer; 1 esophageal cancer; 1 nasopharyngeal cancer; 1 hepatocarcinoma; 1 breast cancer) with pre-radiotherapy MR imaging for a total of 58 dorsal vertebral bodies, 29 metastatic and 29 non-metastatic were included. Each vertebral body was contoured in T1 and T2 weighted images at a radiotherapy delineation console. The obtained data were transferred to an automated data extraction system for morphological, statistical and textural analysis. Eighty-nine features for each lesion in both T1 and T2 images were computed as the median of by-slice values. A Wilcoxon test was applied to the 89 features and the most statistically significant of them underwent to a stepwise feature selection, to find the best performing predictors of metastasis in a logistic regression model. An internal cross-validation via bootstrap was conducted for estimating the model performance in terms of the area under the curve (AUC) of the receiver operating characteristic. Of the 89 textural features tested, 16 were found to differ with statistical significance in the metastatic vs non-metastatic group. The best performing model was constituted by two predictors for T1 and T2 images, namely one morphological feature (center of mass shift) (p value < 0.01) for both datasets and one histogram feature minimum grey level (p value < 0.01) for T1 images and one textural feature (grey-level co-occurrence matrix joint variance (p value < 0.01) for T2 images. The internal cross-validation showed an AUC of 0.8141 (95% CI 0.6854-0.9427) in T1 images and 0.9116 (95% CI 0.8294-0.9937) in T2 images. The results suggest that MRI-based radiomic analysis on oncological patients with bone marrow metastatic disease is able to differentiate between metastatic and non-metastatic vertebral bodies. The most significant predictors of metastasis were found to be based on T2 sequence and were one morphological and one textural feature.

Tenosynovial chondromatosis of the wrist presenting with acute carpal tunnel syndrome: A case report

We report a case of synovial chondromatosis of the wrist that manifested as acute carpal tunnel syndrome. The patient successfully underwent carpal tunnel release, tenosynovectomy and resection of dorsal and volar ossified bodies embedded in the tenosynovium overlying the wrist. Final histopathology confirmed the diagnosis of synovial chondromatosis. The patient's symptoms of pain, numbness, and paresthesia in a median nerve distribution resolved completely and the patient resumed full-time work in the service industry 4-weeks postoperatively with no functional limitations. This case highlights the importance of maintaining a broad differential in the approach to wrist pain and the role of magnetic resonance imaging in the diagnosis of synovial chondromatosis given its variable degree of ossification.

Histological identification of phrenic afferent projections to the spinal cord

Limited data are available regarding the spinal projections of afferent fibers in the phrenic nerve. We describe a method that robustly labels phrenic afferent spinal projections in adult rats. The proximal end of the cut phrenic nerve was secured in a microtube filled with a transganglionic tracer (cholera toxin β-subunit, CT-β, or Cascade Blue) and tissues harvested 96-h later. Robust CT-β labeling occurred in C3-C5 dorsal root ganglia cell bodies and phrenic afferent projections were identified in the mid-cervical dorsal horn (laminae I–III), intermediate grey matter (laminae IV, VII) and near the central canal (laminae X). Afferent fiber labeling was reduced or absent when CT-β was delivered to the intrapleural space or directly to the hemidiaphragm. Soaking the phrenic nerve with Cascade Blue also produced robust labeling of mid-cervical dorsal root ganglia cells bodies, and primary afferent fibers were observed in spinal grey matter and dorsal white matter. Our results show that the ‘nerve soak’ method effectively labels both phrenic motoneurons and phrenic afferent projections, and show that primary afferents project throughout the ipsilateral mid-cervical gray matter.

Evaluating the Analgesic Effect of the GLS Inhibitor 6-Diazo-5-Oxo-L-Norleucine in Vivo.

Glutamate is an excitatory neurotransmitter, produced by its synthetic enzyme, glutaminase (GLS), and packaged by vesicular transporters (VGluT2) into synaptic vesicles. Primary sensory peripheral nerve and spinal synaptic terminals release glutamate during nociceptive (pain) signaling. In post-incisional and inflammation models in rats, GLS and VGluT2 production is elevated in dorsal root ganglion neuronal cell bodies and transported to peripheral and spinal terminals for increased glutamate synthesis and release. 6-Diazo-5-oxo-l-norleucine (DON) is a GLS inhibitor that produces long lasting pain relief when applied to the inflamed paw of arthritic rats, but its effect in a post-incisional model has not been evaluated. In this study, we examined the analgesic efficacy of DON in a surgical incision model by measuring thermal latency and mechanical allodynia. Following behavioral evaluation, we examined the skin for VGluT2, GLS and glutamate immunoreactivity (ir). Our findings revealed that VGluT2-ir is elevated in the stratum lucidum by approximately 19%, 64 hours post-surgical incision and attenuated by approximately 5.4% after the administration of DON. During that same period GLS-ir was elevated in dermal nerve fibers by 52% and was attenuated by approximately 27.9% after the application of DON. Additionally, glutamate-ir was elevated in epidermal nerve fibers by 35% after incision and attenuated by approximately 23% after the administration of DON. Behavioral testing 24 and 48 hours after a single local administration of DON showed five out of six animals having an analgesic response to mechanical allodynia, but not to thermal hyperalgesia. Following a surgical incision, the area of injury shows increased VGluT2-, GLS-, glutamate-ir, mechanical allodynia and no change in thermal latency. After the application of the GLS inhibitor, DON, nerve fiber of the skin showed decreased VGluT2, GLS, and glutamate-ir. Furthermore, post-incision DON treated animals exhibited decreased mechanical allodynia with no change in thermal latency when compared to control animals.

Morphological and molecular characterisation of Notosolenus urceolatus Larsen and Patterson 1990, a member of an understudied deep-branching euglenid group (petalomonads).

Petalomonads are particularly important for understanding the early evolution of euglenids, but are arguably the least studied major group within this taxon. We have established a culture of the biflagellate petalomonad Notosolenus urceolatus, and conducted electron microscopy observations and molecular phylogenetic analysis. Notosolenus urceolatus has eight pellicular strips bordered by grooves and underlain by close-set microtubules. There are ventral and dorsal Golgi bodies. Mitochondria apparently contain fibrous inclusions, as in Petalomonas cantuscygni. A previously undocumented type of large, globular extrusome is present instead of the tubular extrusomes characteristic of Euglenozoa. The feeding apparatus lacks rods and vanes, and is partly supported by an "MTR". The flagella have complex transition zones that are extremely elongated but unswollen. Only the emergent portion of the anterior flagellum has an organised paraxonemal rod, and also has very fine mastigonemes. The basal bodies are offset and lack connecting fibres. 18S rRNA gene phylogenies show that N. urceolatus is closely related to Petalomonas sphagnophila and P. cantuscygni, not Notosolenus ostium, confirming that current generic assignments based on the number of emergent flagella are phylogenetically unreliable, and making it difficult to infer whether features shared by N. urceolatus and P. cantuscygni (for example) are general for petalomonads.

Reconciling the bizarre inheritance of microtubules in complex (euglenid) microeukaryotes

We introduce a hypothetical model that explains how surface microtubules in euglenids are generated, integrated and inherited with the flagellar apparatus from generation to generation. The Euglenida is a very diverse group of single-celled eukaryotes unified by a complex cell surface called the "pellicle", consisting of proteinaceous strips that run along the longitudinal axis of the cell and articulate with one another along their lateral margins. The strips are positioned beneath the plasma membrane and are reinforced with subtending microtubules. Euglenids reproduce asexually, and the two daughter cells inherit pellicle strips and associate microtubules from the parent cell in a semi-conservative pattern. In preparation for cell division, nascent pellicle strips develop from the anterior end of the cell and elongate toward the posterior end between two parent (mature) strips, so that the total number of pellicle strips and underlying microtubules is doubled in the predivisional cell. Each daughter cell inherits an alternating pattern of strips consisting of half of the nascent strips and half of the parent (mature) strips. This observation combined with the fact that the microtubules underlying the strips are linked to the flagellar apparatus created a cytoskeletal riddle: how do microtubules associated with an alternating pattern of nascent strips and mature strips maintain their physical relationship to the flagellar apparatus when the parent cell divides? The model of microtubular inheritance articulated here incorporates known patterns of cytoskeletal semi-conservatism and two new inferences: (1) a multigenerational "pellicle microtubule organizing center" (pMTOC) extends from the dorsal root of the flagellar apparatus, encircles the flagellar pocket, and underpins the microtubules of the pellicle; and (2) prior to cytokinesis, nascent pellicle microtubules fall within one of two "left/right" constellations that are linked to one of the two new dorsal basal bodies.

Ultrastructural characterization of tryptophan hydroxylase 2-specific cortical serotonergic fibers and dorsal raphe neuronal cell bodies after MDMA treatment in rat

3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") is a widely used recreational drug known to cause selective long-term serotonergic damage. The aim of this study was to characterize the ultrastructure of serotonergic pericarya and proximal neurites in the dorsal raphe nucleus as well as the ultrastructure of serotonergic axons in the frontal cortex of adolescent Dark Agouti rats 3 days after treatment with 15 mg/kg i.p. MDMA. Light microscopic immunohistochemistry and pre-embedding immunoelectron microscopy with a novel tryptophan hydroxylase-2 (Tph2) specific antibody, as a marker of serotonergic structures. Light microscopic analysis showed reduced serotonergic axon density and aberrant swollen varicosities in the frontal cortex of MDMA-treated animals. According to the electron microscopic analysis, Tph2 exhibited diffuse cytoplasmic immunolocalization in dorsal raphe neuronal cell bodies. The ultrastructural-morphometric analysis of these cell bodies did not indicate pathological changes or significant alteration in the cross-sectional areal density of any examined organelles. Proximal serotonergic neurites in the dorsal raphe exhibited no ultrastructural alteration. However, in the frontal cortex among intact fibers, numerous serotonergic axons with destructed microtubules were found. Most of their mitochondria were intact, albeit some injured axons also contained degenerating mitochondria; moreover, a few of them comprised confluent membrane whorls only. Our treatment protocol does not lead to ultrastructural alteration in the serotonergic dorsal raphe cell bodies and in their proximal neurites but causes impairment in cortical serotonergic axons. In these, the main ultrastructural alteration is the destruction of microtubules although a smaller portion of these axons probably undergo an irreversible damage.

The 5-HT2A receptor is mainly expressed in nociceptive sensory neurons in rat lumbar dorsal root ganglia

Several lines of evidence indicate that peripheral 5-HT2A receptors are involved in the development of inflammatory and neuropathic pain. However, their localization in sensory cell bodies is not accurately known. We therefore studied 5-HT2A receptor distribution in rat lumbar dorsal root ganglia using immunocytochemistry. Forty percent of L3 lumbar dorsal root ganglion cells were immunoreactive for 5-HT2A receptor. Most were small- to medium-sized cell bodies. Double-labeled experiments revealed that they expressed various chemical phenotypes. The smaller 5-HT2AR cell bodies often bind the isolectin B4 although some 5-HT2AR cell bodies also express substance P (SP). Many 5-HT2A-positive small dorsal root ganglion cells expressed the capsaicin receptor transient receptor potential vanilloid type 1 receptor (TRPV1), confirming their nociceptive nature. In addition, a few large cell bodies were labeled for 5-HT2A, and they also expressed NF200 suggesting that they were at the origin of Aδ or Aβ fibers. A total absence of double labeling with parvalbumin showed that they were not proprioceptors. 5-HT2A immunoreactivity in dorsal root ganglia cells was found in the cytoplasm and along the plasma membrane at the interface between sensory cell and the adjacent satellite cells; this distribution was confirmed under the electron microscope, and suggested a functional role for the 5-HT2A receptor at these sites. We therefore investigated the presence of 5-HT and 5-HIAA in lumbar dorsal root ganglia by high performance liquid chromatography. There were 5.75±0.80 ng 5-HT and 3.19±0.37 ng 5-hydroxyindoleacetic acid (5-HIAA) per mg of protein with a ratio 5-HIAA/5-HT of 0.67±0.10, similar to values typically observed in brain tissues. These findings suggest that 5-HT, via the 5-HT2AR, may be involved in the peripheral control of sensory afferents, mainly unmyelinated nociceptors and to a lesser extent neurons with Aδ or Aβ fibers, and in the control of cellular excitability of some dorsal root cell bodies through a paracrine mechanism of action.

Neurosecretory cells in the central nervous system of the red slug Arion rufus L

ABSTRACT The neurosecretory system of the forest red slug Arion rufus was studied using the alcian blue/alcian yellow (AB/AY) staining technique for neurosecretion. Stainable cells were identified in the paired cerebral, pleural, parietal, pedal, and buccal ganglia, and in the visceral ganglion. The cells occur as single cells or in groups of up to 30, each with diameters ranging from 15 to 130 mm. Axon tracts could only be traced for some groups of cells; neurohemal areas were identified for some neurosecretory cells in the cerebral ganglia. The morphological features of the neurosecretory system of A. rufus are compared with those of other investigated stylommatophoran slugs. The ultrastructural studies of both cerebral ganglia and connective tissue that surrounds it, reveal that nervous control of an endocrine organ, “the dorsal bodies, by cerebral dark green cells might be taken into consideration.

Structural Changes in Fat Body of Aedes aegypti Caused by Aging and Blood Feeding

The fat body is the intermediary metabolism organ of insects and the main source of hemolymph components. In the current study, the microanatomy of Aedes aegypti (L., 1762) fat body was studied through scanning electron microscopy to observe the effects of blood feeding and aging. Three groups of female mosquitoes were used: newly emerged females, 18-d-old sugar-fed females, and 18-d-old blood-fed females. In Ae. aegypti, the fat body is located beneath the integument, and it is subdivided into dorsal, ventral, and lateral lobes, with the latter two being larger than the dorsal lobes. The lobes projected into the body cavity, and they were covered externally by a basal lamina with rounded cells beneath it. In 18-d-old sugar-fed females, the ventral and dorsal fat bodies seemed more developed than in newly emerged mosquitoes. The fat body hypertrophy caused by aging in the sugar-fed mosquito was probably associated with lipid accumulation due to the sugar diet. The blood-fed 18-d-old mosquitoes showed flattened fat bodies in all locations. The fat body modifications after the blood ingestion may be associated with midgut expansion after blood feeding, followed by ovary hypertrophy that mechanically compresses the fat body against the body wall. The structural changes in the fat body after a bloodmeal may be important for midgut extension to maximize blood storage and subsequent ovary enlargement, leading to the organ’s reorganization in the body cavity. In addition, the depletion of fat body content during vitellogenesis could be responsible for the shrinking and flattening of the fat body lobes.

Structural Changes in Fat Body of &lt;I&gt;Aedes aegypti&lt;/I&gt; Caused by Aging and Blood Feeding

The fat body is the intermediary metabolism organ of insects and the main source of hemolymph components. In the current study, the microanatomy of Aedes aegypti (L., 1762) fat body was studied through scanning electron microscopy to observe the effects of blood feeding and aging. Three groups of female mosquitoes were used: newly emerged females, 18-d-old sugar-fed females, and 18-d-old blood-fed females. In Ae. aegypti, the fat body is located beneath the integument, and it is subdivided into dorsal, ventral, and lateral lobes, with the latter two being larger than the dorsal lobes. The lobes projected into the body cavity, and they were covered externally by a basal lamina with rounded cells beneath it. In 18-d-old sugar-fed females, the ventral and dorsal fat bodies seemed more developed than in newly emerged mosquitoes. The fat body hypertrophy caused by aging in the sugar-fed mosquito was probably associated with lipid accumulation due to the sugar diet. The blood-fed 18-d-old mosquitoes showed flattened fat bodies in all locations. The fat body modifications after the blood ingestion may be associated with midgut expansion after blood feeding, followed by ovary hypertrophy that mechanically compresses the fat body against the body wall. The structural changes in the fat body after a bloodmeal may be important for midgut extension to maximize blood storage and subsequent ovary enlargement, leading to the organ's reorganization in the body cavity. In addition, the depletion of fat body content during vitellogenesis could be responsible for the shrinking and flattening of the fat body lobes.