Neurofilament Immunostaining Research Articles

Axonal Protection by Oral Nicotinamide Riboside Treatment with Upregulated AMPK Phosphorylation in a Rat Glaucomatous Degeneration Model.

Nicotinamide riboside (NR), a precursor of nicotinamide adenine dinucleotide (NAD+), has been studied to support human health against metabolic stress, cardiovascular disease, and neurodegenerative disease. In the present study, we investigated the effects of oral NR on axonal damage in a rat ocular hypertension model. Intraocular pressure (IOP) elevation was induced by laser irradiation and then the rats received oral NR of 1000 mg/kg/day daily. IOP elevation was seen 7, 14, and 21 days after laser irradiation compared with the controls. We confirmed that oral NR administration significantly increased NAD+ levels in the retina. After 3-week oral administration of NR, morphometric analysis of optic nerve cross-sections showed that the number of axons was protected compared with that in the untreated ocular hypertension group. Oral NR administration significantly prevented retinal ganglion cell (RGC) fiber loss in retinal flat mounts, as shown by neurofilament immunostaining. Immunoblotting samples from the optic nerves showed that oral NR administration augmented the phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK) level in rats with and without ocular hypertension induction. Immunohistochemical analysis showed that some p-AMPK-immunopositive fibers were colocalized with neurofilament immunoreactivity in the control group, and oral NR administration enhanced p-AMPK immunopositivity. Our findings suggest that oral NR administration protects against glaucomatous RGC axonal degeneration with the possible upregulation of p-AMPK.

Apitoxin alleviates methyl mercury-induced peripheral neurotoxicity in male rats by regulating dorsal root ganglia neuronal degeneration and oxidative stress

Methylmercury (MeHg) toxicity is associated with extensive neuronal degeneration of dorsal root ganglia (DRG). This study aimed to assess the ameliorative effect of bee venom (BV) on methyl mercury chloride (MeHgCl)-induced peripheral neurotoxicity using DRGs in rats. Forty-eight adult male Sprague Dawley rats were allocated into four equal groups: G I: control (gavaged MilliQ water 1 ml/rat), G II: subcutaneously injected with BV (0.5 mg/kg b.wt), G III: gavaged MeHgCl (6.7 mg/kg b.wt), and G IV: received MeHgCl+BV. Dosing was done five times/week for 2 weeks. Ataxic behavior and visual impairments were significantly increased, whereas the movement behavior and motility gait were suppressed in the MeHgCl group. MeHgCl significantly decreased total antioxidant capacity (TAC) in DRG and significantly decreased the serum levels of glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). Tumor necrosis factor-alpha (TNF-α) and interleukin 1β (IL-1β) levels were significantly elevated, whereas interleukin 10 (IL-10) levels were significantly decreased in the MeHgCl group compared with the control group. DRGs of the MeHgCl-exposed rats showed pyknotic shrunken neurons with perineural vacuolations, demyelination of nerve axons, and proliferation of the satellite cells. MeHgCl significantly induced a higher positive index ratio of Iba-1, SOX10, neurofilament, pan-neuron, and vimentin immunostaining in the DRG. BV administration significantly mitigated the MeHgCl-induced alterations in oxidative stress-related indices. BV modified the immunostaining of Iba-1, SOX10, neurofilament, pan-neuron, and vimentin-positive index ratio in the DRG of the MeHgCl group. Our findings acknowledged that BV could enhance in vivo neuroprotective effects against MeHgCl-induced DRGs damage in male rats.

Origin, branching pattern, foraminal and intraspinal distribution of the human lumbar sinuvertebral nerves

BACKGROUND CONTEXTThe lumbar sinuvertebral nerve (SVN) innervates the outer posterior intervertebral disc (IVD); it is thought to mediate discogenic low-back pain (LBP). Controversy, however, exists on its origins at higher (L1–L2) versus lower (L3–L5) lumbar levels. Additionally, lack of knowledge regarding its foraminal and intraspinal branching patterns and extensions may lead to iatrogenic damage. PURPOSETo systematically describe the origins of the L2 and L5 SVNs, their morphological variation in the intervertebral foramen (IVF) and intraspinal distribution. STUDY DESIGNDissection-based study of 20 SVNs with histological confirmation in five embalmed human cadavers. METHODSThe origin, branching pattern and distribution of the L2 and L5 SVNs was investigated bilaterally in five human cadavers using dorsal and anterolateral dissection approaches. Parameters studied included somatic and/or autonomic SVN root contributions, foraminal SVN morphology and course, diameter, branching point, intraspinal distribution and IVD innervation pattern. Nerve tissue was confirmed by immunostaining for neurofilament and S100 proteins. RESULTSThe SVN and its origins was identified in all except one IVF at L2 and in all foramina at L5. At L2, the SVN arose in nearly 90% of sides from both somatic and autonomic roots and at L5 in 40% of sides. The remaining SVNs were formed by purely autonomic roots. The SVN arose from significantly more roots at L2 than L5 (3.1 ± 0.3 vs. 1.9 ± 0.3, respectively; p=.022). Four different SVN morphologies could be discerned in the L2 IVF: single filament (22%), multiple (parallel or diverging) filament (33%), immediate splitting (22%) and plexiform (22%) types, whereas the L5 SVN consisted of single (90%) and multiple (10%) filament types. SVN filaments were significantly thicker at L2 than L5 (0.48 ± 0.06 mm vs. 0.33 ± 0.02 mm, respectively; p=.043). Ascending SVN filaments coursed roughly parallel to the exiting spinal nerve root trajectory at L2 and L5. Branching of the SVN into ascending and descending branches occurred mostly intraspinal both at L2 and L5. Spinal canal distribution was also similar for L2 and L5 SVNs. Lumbar posterior IVDs were innervated by the descending branch of the parent SVN and ascending branch of the subjacent SVN. CONCLUSIONSThe SVN at L2 originates from both somatic and autonomic roots in 90% of cases and at L5 in 40% of cases. The remaining SVNs are purely autonomic. In the IVF, the L2 SVN is morphologically heterogeneous, but generally consists of numerous filaments, whereas at L5 90% contains a single SVN filament. The L2 SVN is formed by more roots and is thicker than the L5 SVN. Intraspinal SVN distribution is confined to its level of origin; lumbar posterior IVDs are innervated by corresponding and subjacent SVNs (ie, two spinal levels). CLINICAL SIGNIFICANCEOur findings indicate that L5 discogenic LBP may be mediated both segmentally and nonsegmentally in 40% of cases and nonsegmentally in 60% of cases. Failure of lower lumbar discogenic pain treatment may be the result of only interrupting the nonsegmental pathway, but not the segmental one as well. Relating SVN anatomy to microsurgical spinal approaches may prevent iatrogenic damage to the SVN and the formation of postsurgical back pain.

Optimal Ratio of Wnt3a Expression in Human Mesenchymal Stem Cells Promotes Axonal Regeneration in Spinal Cord Injured Rat Model.

ObjectiveThrough our previous clinical trials, the demonstrated therapeutic effects of MSC in chronic spinal cord injury (SCI) were found to be not sufficient. Therefore, the need to develop stem cell agent with enhanced efficacy is increased. We transplanted enhanced Wnt3a-secreting human mesenchymal stem cells (hMSC) into injured spines at 6 weeks after SCI to improve axonal regeneration in a rat model of chronic SCI. We hypothesized that enhanced Wnt3a protein expression could augment neuro-regeneration after SCI. MethodsThirty-six Sprague-Dawley rats were injured using an Infinite Horizon (IH) impactor at the T9–10 vertebrae and separated into five groups : 1) phosphate-buffered saline injection (injury only group, n=7); 2) hMSC transplantation (MSC, n=7); 3) hMSC transfected with pLenti vector (without Wnt3a gene) transplantation (pLenti-MSC, n=7); 4) hMSC transfected with Wnt3a gene transplantation (Wnt3a-MSC, n=7); and 5) hMSC transfected with enhanced Wnt3a gene (1.7 fold Wnt3a mRNA expression) transplantation (1.7 Wnt3a-MSC, n=8). Six weeks after SCI, each 5×105 cells/15 µL at 2 points were injected using stereotactic and microsyringe pump. To evaluate functional recovery from SCI, rats underwent Basso-Beattie-Bresnahan (BBB) locomotor test on the first, second, and third days post-injury and then weekly for 14 weeks. Axonal regeneration was assessed using growth-associated protein 43 (GAP43), microtubule-associated protein 2 (MAP2), and neurofilament (NF) immunostaining. ResultsFourteen weeks after injury (8 weeks after transplantation), BBB score of the 1.7 Wnt3a-MSC group (15.0±0.28) was significantly higher than that of the injury only (10.0±0.48), MSC (12.57±0.48), pLenti-MSC (12.42±0.48), and Wnt3a-MSC (13.71±0.61) groups (p<0.05). Immunostaining revealed increased expression of axonal regeneration markers GAP43, MAP2, and NF in the Wnt3a-MSC and 1.7 Wnt3a-MSC groups. ConclusionOur results showed that enhanced gene expression of Wnt3a in hMSC can potentiate axonal regeneration and improve functional recovery in a rat model of chronic SCI.

Negative α-synuclein pathology in the submandibular gland of patients carrying PRKN pathogenic variants

IntroductionAlpha-synuclein (AS) pathology in the peripheral nervous tissue is a potential pathological biomarker in Parkinson disease (PD). Several studies reported the excellent specificity of the AS pathology of the submandibular gland (SMG) biopsy in PD. PRKN pathogenic variant is one of the major genetic causes of young-onset PD without Lewy pathology in the brain. In this study, we evaluated peripheral AS pathology in the SMG biopsy of patients with PRKN pathogenic variants. MethodsWe enrolled three young-onset PD patients with PRKN pathogenic variants. Two patients were compound heterozygous for trans-exon 3 and 4 deletions and one patient was heterozygous for an exon 2 duplication. We obtained two submandibular gland tissues with core needle biopsy (18G). The neural structures were identified using neurofilament (NF) immunostaining and the neural tissue in the adjacent section were stained with 129 phophorylated α-synuclein (pAS) antibody.Results: pAS staining in the SMG was negative in all cases with the PRKN pathogenic variants. ConclusionsOur data may support the high specificity of the AS pathology of SMG in α-synuclein associated parkinsonism. Future studies evaluating peripheral neural tissue including the SMG in the elderly healthy population are required to validate the role of peripheral AS pathology as a biomarker in PD.

Cardiac sympathetic denervation and synucleinopathy in Alzheimer’s disease with brain Lewy body disease

Comorbid Lewy body pathology is very common in Alzheimer’s disease and may confound clinical trial design, yet there is no in vivo test to identify patients with this. Tissue (and/or radioligand imaging) studies have shown cardiac sympathetic denervation in Parkinson’s disease and dementia with Lewy bodies, but this has not been explored in Alzheimer’s subjects with Lewy bodies not meeting dementia with Lewy bodies clinicopathological criteria. To determine if Alzheimer’s disease with Lewy bodies subjects show sympathetic cardiac denervation, we analysed epicardial and myocardial tissue from autopsy-confirmed cases using tyrosine hydroxylase and neurofilament immunostaining. Comparison of tyrosine hydroxylase fibre density in 19 subjects with Alzheimer’s disease/dementia with Lewy bodies, 20 Alzheimer’s disease with Lewy bodies, 12 Alzheimer’s disease subjects without Lewy body disease, 19 Parkinson’s disease, 30 incidental Lewy body disease and 22 cognitively normal without Alzheimer’s disease or Lewy body disease indicated a significant group difference (P < 0.01; Kruskal–Wallis analysis of variance) and subsequent pair-wise Mann–Whitney U tests showed that Parkinson’s disease (P < 0.05) and Alzheimer’s disease/dementia with Lewy bodies (P < 0.01) subjects, but not Alzheimer’s disease with Lewy bodies subjects, had significantly reduced tyrosine hydroxylase fibre density as compared with cognitively normal. Both Parkinson’s disease and Alzheimer’s disease/dementia with Lewy bodies subjects also showed significant epicardial losses of neurofilament protein-immunoreactive nerve fibre densities within the fibre bundles as compared with cognitively normal subjects (P < 0.01) and both groups showed high pathologic alpha-synuclein densities (P < 0.0001). Cardiac alpha-synuclein densities correlated significantly with brain alpha-synuclein (P < 0.001), while cardiac tyrosine hydroxylase and neurofilament immunoreactive nerve fibre densities were negatively correlated with the densities of both brain and cardiac alpha-synuclein, as well as Unified Parkinson’s Disease Rating Scale scores (P < 0.05). The clear separation of Alzheimer’s disease/dementia with Lewy bodies subjects from Alzheimer’s disease and cognitively normal, based on cardiac tyrosine hydroxylase fibre density, is the first report of a statistically significant difference between these groups. Our data do not show significant sympathetic cardiac denervation in Alzheimer’s disease with Lewy bodies, but strongly confirm that cardiac nuclear imaging with a noradrenergic radioligand is worthy of further study as a potential means to separate Alzheimer’s disease from Alzheimer’s disease/dementia with Lewy bodies during life.

Protein Expression Profile on Differentiation of Bone Marrow Mesenchymal Stem Cells into Retinal Ganglion-Like Cells.

To explore possible approaches to differentiating rat bone marrow mesenchymal stem cells (BMSCs) into retinal ganglion-like cells and to demonstrate the dynamic changes in protein expression profiles of BMSCs throughout the differentiation. BMSCs were isolated from adult rats and cultured in medium conditioned by neonatal rat retinal cells to induce BMSC differentiation into retinal ganglion-like cells. Immunostaining for neurofilament, nestin, Map2, and Thy1.1 was used to follow the differentiation process. Two types of protein arrays were employed to profile the BMSCs, the differentiated retinal ganglion-like cells, and the primary retinal ganglion cells (RGCs) using the Biomarker Wizard System. After 7 days of culture in conditioned medium, cells showing a neural-cell-like modality appeared. The differentiated retinal ganglion-like cells showed that network-like connections were positive for nestin, neurofilament, Map2, and Thy1.1. In total, 16 marker proteins were highly expressed in both retinal ganglion-like cells and RGCs and no obvious expression was observed in BMSCs. Among them, nine proteins were expressed more highly in RGCs than in retinal ganglion-like cells. BMSCs can be induced to differentiate into retinal ganglion-like cells by neonatal rat retinal cells, and the induced cells show protein profiles resembling those of isolated RGCs.

Adult Mice Lacking Mct8 and Dio2 Proteins Present Alterations in Peripheral Thyroid Hormone Levels and Severe Brain and Motor Skill Impairments.

Background: Mutations in the thyroid hormone (TH) transporter monocarboxylate transporter 8 (MCT8) lead to peripheral hyperthyroidism and profound psychomotor alterations in humans. Mice lacking Mct8 present peripheral hyperthyroidism but no gross neurological abnormalities due to brain compensatory mechanisms involving the enzyme deiodinase type 2 (Dio2). Methods: Here we have analyzed the endocrine and neurologic phenotype of mice lacking both Mct8 and Dio2 at three and six months of age. Thyroxine (T4) and 3,5,3' triiodothyronine (T3) levels/content were measured by specific radioimmunoassays; motor skill performance was evaluated by the footprint, rotarod, four limb hanging wire, and balance beam tests; and brain histological analysis was performed by immunostaining for neurofilament and parvalbumin. Results: We have found that this mouse model presents peripheral hyperthyroidism and brain hypothyroidism. Interestingly, the severity of the brain hypothyroidism seems permanent and varies across regions, with the striatum being a particularly affected area. We have also found brain alterations at the histological level compatible with TH deficiency and impaired motor skills. Conclusions: These findings indicate the potential of Mct8/Dio2-deficient mice to represent a model for human MCT8 deficiency, to understand the mechanisms underlying its pathophysiology, and ultimately design therapeutic interventions for human patients.

Palisaded Encapsulated (Solitary Circumscribed) Neuroma: A Review of 30 Cases.

Background. Solitary circumscribed neuroma (SCN), also known as palisaded encapsulated neuroma (PEN), is a benign neural tumor. It may be mistaken as either schwannoma or neurofibroma in pathology practice. In this study, we aimed to define clinicopathologic and immunohistochemical features and discuss its differential diagnosis. Materials and Methods. The histopathological features of 30 cases of SCN/PEN were reviewed. The presence of intralesional axons, Schwann, and perineural cell distributions were investigated by performing neuronal immunomarkers. Results. Twelve cases were females, and 18 cases were males. The mean age was 48 years. Lesions were mostly located on the face (27/30). Histologically, 18 had a lobular pattern, 9 were plexiform, 2 fungating, and 1 multilobular. Although the majority of cases were well circumscribed, capsular integrity was at least focally disrupted (73%). Verocay body was noted only in 6 cases (20%). One case showed excessive hyperkeratosis, forming a keratin horn. Adipocytic change was detected in another case. The lesions consisted of S100-positive Schwann cell proliferation and were partially surrounded by perineural cells highlighted by EMA or Claudin-1. The amount of intralesional axons revealed by neurofilament immunostaining was variable. Conclusion. SCN/PEN is a relatively common lesion, and usually seen as an asymptomatic papule on the face of elderly patients. A circumscribed lesion composed of bundles of bland-looking spindle cells thought to be of neural origin is seen in the dermis. Pathologists should be aware of the existence of plexiform and multilobular PEN/SCN variants, to avoid misdiagnosis of plexiform neurofibroma or schwannoma.

Histological and immunohistochemical study of the potential therapeutic impacts of bone marrow mesenchymal stem cells and exosomes for sciatic nerve crush injury model in rats

ABSTRACTThe aim was to evaluate the potential effect of bone marrow-derived mesenchymal stem cells (BMSC) and BMSC-EX in the sciatic nerve injury. Forty-five rats were divided into four groups, i.e. Group I control no surgery or treatment, Group II sciatic nerve crush surgery and 1 week post-surgery, Group III sciatic nerve crush injury was treated with BMSC, and Group IV sciatic nerve crush injury was treated with BMSC-EX. All animal groups were euthanized 2 weeks after treatment. Sciatic nerves were examined histologically and immunohistochemically. Group II showed various histological changes, i.e. vacuolation, degeneration and loss of nerve fibers. Group II showed a significant increase in collagen fibers, but with significant reduction in osmium tetroxide (OsO4)-stained myelin sheaths and neurofilament immunostaining compared to Group I. Group II also revealed distortion and disruption of myelinated nerve fibers. Groups III and IV showed significant improvement of both histological and immunohistochemical changes in Group II. BMSC and BMSC-EX were shown to improve axonal regeneration.

Clinical, genetic and neuropathological characterization of spinocerebellar ataxia type 37.

The autosomal dominant spinocerebellar ataxias (SCAs) consist of a highly heterogeneous group of rare movement disorders characterized by progressive cerebellar ataxia variably associated with ophthalmoplegia, pyramidal and extrapyramidal signs, dementia, pigmentary retinopathy, seizures, lower motor neuron signs, or peripheral neuropathy. Over 41 different SCA subtypes have been described evidencing the high clinical and genetic heterogeneity. We previously reported a novel spinocerebellar ataxia type subtype, SCA37, linked to an 11-Mb genomic region on 1p32, in a large Spanish ataxia pedigree characterized by ataxia and a pure cerebellar syndrome distinctively presenting with early-altered vertical eye movements. Here we demonstrate the segregation of an unstable intronic ATTTC pentanucleotide repeat mutation within the 1p32 5' non-coding regulatory region of the gene encoding the reelin adaptor protein DAB1, implicated in neuronal migration, as the causative genetic defect of the disease in four Spanish SCA37 families. We describe the clinical-genetic correlation and the first SCA37 neuropathological findings caused by dysregulation of cerebellar DAB1 expression. Post-mortem neuropathology of two patients with SCA37 revealed severe loss of Purkinje cells with abundant astrogliosis, empty baskets, occasional axonal spheroids, and hypertrophic fibres by phosphorylated neurofilament immunostaining in the cerebellar cortex. The remaining cerebellar Purkinje neurons showed loss of calbindin immunoreactivity, aberrant dendrite arborization, nuclear pathology including lobulation, irregularity, and hyperchromatism, and multiple ubiquitinated perisomatic granules immunostained for DAB1. A subpopulation of Purkinje cells was found ectopically mispositioned within the cerebellar cortex. No significant neuropathological alterations were identified in other brain regions in agreement with a pure cerebellar syndrome. Importantly, we found that the ATTTC repeat mutation dysregulated DAB1 expression and induced an RNA switch resulting in the upregulation of reelin-DAB1 and PI3K/AKT signalling in the SCA37 cerebellum. This study reveals the unstable ATTTC repeat mutation within the DAB1 gene as the underlying genetic cause and provides evidence of reelin-DAB1 signalling dysregulation in the spinocerebellar ataxia type 37.

Dopamine D2 receptor expression in the corticotroph cells of the human normal pituitary gland.

The dopamine D2 receptor is the main dopamine receptor expressed in the human normal pituitary gland. The aim of the current study was to evaluate dopamine D2 receptor expression in the corticotroph cell populations of the anterior lobe and pars intermedia, as well as posterior lobe of the human normal pituitary gland by immunohistochemistry. Human normal pituitary gland samples obtained from routine autopsies were used for the study. In all cases, histology together with immunostaining for adrenocorticotropic hormone, melanocyte-stimulating hormone, prolactin, and neurofilaments were performed and compared to the immunostaining for D2 receptor. D2 receptor was heterogeneously expressed in the majority of the cell populations of the anterior and posterior lobe as well as in the area localized between the anterior and posterior lobe, and arbitrary defined as "intermediate zone". This zone, characterized by the presence of nerve fibers included the residual pars intermedia represented by the colloid-filled cysts lined by the remnant melanotroph cells strongly expressing D2 receptors, and clusters of corticotroph cells, belonging to the anterior lobe but localized within the cysts and adjacent to the posterior lobe, variably expressing D2 receptors. D2 dopamine receptor is expressed in the majority of the cell populations of the human normal pituitary gland, and particularly, in the different corticotroph cell populations localized in the anterior lobe and the intermediate zone of the pituitary gland.

Valproic acid ameliorates olfactory dysfunction in APP/PS1 transgenic mice of Alzheimer's disease: Ameliorations from the olfactory epithelium to the olfactory bulb

Olfactory dysfunction is a common and early symptom of many neurodegenerative diseases, particularly of Alzheimer's disease (AD) and mild cognitive impairment, pointing to the progression to dementia. Recent studies have revealed that valproic acid (VPA) has neuroprotective effects in rodent models of AD. In this study, we investigated the effects of VPA on olfactory dysfunction of APP/PS1 double transgenic mouse models of AD. After continuous treatment with a 100mg/kg daily dose of VPA for 3months, APP/PS1 mice showed improved olfactory performances. In agreement with the behavioral findings, VPA treatment reduced amyloid β (Aβ) burden in the olfactory epithelium (OE) of transgenic mice. And, VPA increased epithelial thickness of the olfactory mucosa through decreased cell apoptosis and increased cell proliferation. In the olfactory bulb (OB), VPA administration also reduced senile plaques and levels of soluble and insoluble Aβ42 peptides. Besides, VPA promoted the increase of mitral cells and decrease of neurofilament immunostaining. In hence, VPA treatment completely improved the olfactory performances and prevented degenerative changes of the OE and OB. Our study raises the possibility of AD diagnosis by OE biopsy. Moreover, VPA may provide a novel therapeutic strategy for the treatment of olfactory dysfunction in AD patients.

English

Background: Pineal parenchymal tumors (PPTs) are uncommon tumors comprising of pineocytoma (PC), pineal parenchymal tumor of intermediate differentiation (PPTID) and pineoblastoma (PB). Morphological sub typing and histological grading based on mitotic index and neurofilament (NF) immunostaining, are the factors affecting the survival of these patients. Treatment strategy and prognosis of PPTIDs remain controversial with limited data available on pathological features and biological behavior of PPTID. Case series: A series of 8 pineal parenchymal tumors over a period of 5 years are reported here with special reference to PPTIDs. The series includes 3 cases of PC, 2 of PPTID and 3 of PB. Patients underwent decompression, microsurgical/ stereotactic/ endoscopic biopsy. Histological features with MIB1 LI (labelling index) and NF immunostaining were studied and showed varied presentation. One case in each group of PC and PPTID showed ganglion like cells. Both PPTIDs showed 8% and 20% MIB1 LI. All PBs showed brisk mitosis hemorrhage and necrosis except for one case where mitosis was not clearly evident but showed high MIB1 LI (50%).

Intrinsic Connections of the Core Auditory Cortical Regions and Rostral Supratemporal Plane in the Macaque Monkey.

In the ventral stream of the primate auditory cortex, cortico-cortical projections emanate from the primary auditory cortex (AI) along 2 principal axes: one mediolateral, the other caudorostral. Connections in the mediolateral direction from core, to belt, to parabelt, have been well described, but less is known about the flow of information along the supratemporal plane (STP) in the caudorostral dimension. Neuroanatomical tracers were injected throughout the caudorostral extent of the auditory core and rostral STP by direct visualization of the cortical surface. Auditory cortical areas were distinguished by SMI-32 immunostaining for neurofilament, in addition to established cytoarchitectonic criteria. The results describe a pathway comprising step-wise projections from AI through the rostral and rostrotemporal fields of the core (R and RT), continuing to the recently identified rostrotemporal polar field (RTp) and the dorsal temporal pole. Each area was strongly and reciprocally connected with the areas immediately caudal and rostral to it, though deviations from strictly serial connectivity were observed. In RTp, inputs converged from core, belt, parabelt, and the auditory thalamus, as well as higher order cortical regions. The results support a rostrally directed flow of auditory information with complex and recurrent connections, similar to the ventral stream of macaque visual cortex.

Three-layered architecture of the popliteal fascia that acts as a kinetic retinaculum for the hamstring muscles.

When patients report pain in the popliteal fossa upon knee extension, the pain is usually localized in the lower region of the popliteal fossa. However, some patients complain of pain in the upper region of the popliteal fossa as the knee is flexed, which motivated us to examine the role of the popliteal fascia as the retinaculum of the hamstring muscles. Thirty-four thighs from 19 Japanese cadavers were dissected. The popliteal fascia was defined as the single aponeurotic sheet covering the popliteal fossa. We found that the fascia acted as a three-layered retinaculum for the flexor muscles of the thigh and provided a secure route for neurovascular structures to the lower leg in any kinetic position of the knee joint. The superficial layer of the popliteal fascia covering the thigh was strongly interwoven with the epimysium of biceps femoris along its lateral aspect and with that of the semimembranosus along its medial aspect, ensuring that the flexor muscles remained in their correct positions. The intermediate layer arose from the medial side of biceps femoris and merged medially with the superficial layer. The profound layer stretched transversely between the biceps femoris and the semimembranosus. Moreover, we investigated the nerve distribution in the popliteal fascia using Sihler's staining and whole-mount immunostaining for neurofilaments. The three-layered fascia was constantly innervated by branches from the posterior femoral cutaneous or saphenous nerve. The nerves were closely related and distributed to densely packed collagen fibers in the superficial layer as free or encapsulated nerve endings, suggesting that the fascia is involved in pain in the upper region of the popliteal fossa.

The role of rosemary against acrylamide developmental toxicity on the white matter of the rat spinal cord

Objectives The aim of this study was to determine the genotoxicity and developmental toxicity of acrylamide (ACR) on the spinal cord white matter of male albino rats and the possible protective role of rosemary. Background With increasing number of sources of ACR exposure to the general public, the need for understanding the toxicological risk associated with such exposure is in high demand. Materials and methods Eighty male albino rats were used in this study. 20 rats for each group their mothers were given either distilled water, rosemary aqueous extract (RAE) (2.2 ml/kg/twice/week - i.e 0.44 ml/rat) orally, ACR (10 mg/kg/day - i.e 2 mg/rat) orally, or ACR in combination with RAE. The rats were subjected to morphological (clinical) assessent. They were then killed at the age of 1, 7, 14, and 21 days and the thoracic part of the spinal cord was subjected to histological, immunohistochemical, and morphometric studies. Single cell gel electrophoresis (comet assay) was performed on peripheral blood leukocytes. Results ACR administration significantly delayed the normal development, reduced the body measurements, and increased the gait score. The spinal cord white matter of ACR-treated rats showed significant reduction in the number of neuroglia, as well as swollen axons and vacuolation. The area percentage of neurofilament and myelin basic protein immunostaining was reduced. Also, ACR led to DNA damage, which was expressed as significant increase in comet tail length, tail DNA%, and tail moment when compared with the control group. ACR toxicity was age dependent. RAE led to improvement in all tested parameters, especially at younger ages. Conclusion ACR induced its neurotoxic effect through demyelination of axons and alteration of neurofilament protein content. RAE ( Rosmarinus officinalis L.) showed protective effects against developmental toxicity and genotoxicity induced by ACR.

In vivo generation of a mature and functional artificial skeletal muscle.

Extensive loss of skeletal muscle tissue results in mutilations and severe loss of function. In vitro-generated artificial muscles undergo necrosis when transplanted in vivo before host angiogenesis may provide oxygen for fibre survival. Here, we report a novel strategy based upon the use of mouse or human mesoangioblasts encapsulated inside PEG-fibrinogen hydrogel. Once engineered to express placental-derived growth factor, mesoangioblasts attract host vessels and nerves, contributing to in vivo survival and maturation of newly formed myofibres. When the graft was implanted underneath the skin on the surface of the tibialis anterior, mature and aligned myofibres formed within several weeks as a complete and functional extra muscle. Moreover, replacing the ablated tibialis anterior with PEG-fibrinogen-embedded mesoangioblasts also resulted in an artificial muscle very similar to a normal tibialis anterior. This strategy opens the possibility for patient-specific muscle creation for a large number of pathological conditions involving muscle tissue wasting.

Mutations of the thyroid hormone transporter MCT8 cause prenatal brain damage and persistent hypomyelination.

Mutations in the MCT8 (SLC16A2) gene, encoding a specific thyroid hormone transporter, cause an X-linked disease with profound psychomotor retardation, neurological impairment, and abnormal serum thyroid hormone levels. The nature of the central nervous system damage is unknown. The objective of the study was to define the neuropathology of the syndrome by analyzing brain tissue sections from MCT8-deficient subjects. We analyzed brain sections from a 30th gestational week male fetus and an 11-year-old boy and as controls, brain tissue from a 30th and 28th gestational week male and female fetuses, respectively, and a 10-year-old girl and a 12-year-old boy. Staining with hematoxylin-eosin and immunostaining for myelin basic protein, 70-kDa neurofilament, parvalbumin, calbindin-D28k, and synaptophysin were performed. Thyroid hormone determinations and quantitative PCR for deiodinases were also performed. The MCT8-deficient fetus showed a delay in cortical and cerebellar development and myelination, loss of parvalbumin expression, abnormal calbindin-D28k content, impaired axonal maturation, and diminished biochemical differentiation of Purkinje cells. The 11-year-old boy showed altered cerebellar structure, deficient myelination, deficient synaptophysin and parvalbumin expression, and abnormal calbindin-D28k expression. The MCT8-deficient fetal cerebral cortex showed 50% reduction of thyroid hormones and increased type 2 deiodinase and decreased type 3 deiodinase mRNAs. The following conclusions were reached: 1) brain damage in MCT8 deficiency is diffuse, without evidence of focal lesions, and present from fetal stages despite apparent normality at birth; 2) deficient hypomyelination persists up to 11 years of age; and 3) the findings are compatible with the deficient action of thyroid hormones in the developing brain caused by impaired transport to the target neural cells.

G.O.6: Lethal disorder of mitochondrial fission caused by mutations in DNM1L

We describe two siblings, born to non-consanguineous Filipino parents after 12years of infertility, with profound hypotonia, absent respiratory effort, hepatic dysfunction and multiple abnormalities on neuropathological studies at autopsy. The first child, a female, died at 3weeks of age and the second child, a male, died at 5days of life after withdrawal of care. Array CGH, molecular testing of SMN1 , DMPK , POLG1 , and metabolic studies (plasma amino acids, urine organic acids, lactate, very long chain fatty acids, transferrin isoforms) were all normal. Neuropathological examination revealed many neurons in the brain and spinal cord with intracytoplasmic hyaline eosinophilic globules. Electron microscopy showed multiple giant mitochondria within hippocampal neurons which contained elongated cristae arranged parallel to each other. Examination of the spinal cord revealed marked reduction in myelin content and neurofilament immunostaining showed decreased numbers of axons. The posterior nerve roots and peripheral nerve also showed poor myelination with a marked reduction in numbers of myelinated axons. Exome sequencing of DNA from all family members revealed both children were compound heterozygous for a c.261dup in exon 3 and a c.385_386del mutation in exon 5 of the DNM1L gene. The parents were confirmed heterozygous carriers of one of the mutations. The protein encoded by DNM1L is a member of the dynamin superfamily of GTPases and has a critical role in regulating mitochondrial morphology through assembly of fission foci and distribution of mitochondrial tubules throughout the cytoplasm. Drp1 (DNM1L) knock-out mice die shortly after birth and have enlarged, abnormal mitochondria in neuronal cells, defective synaptic development and hepatic dysfunction, similar to our patients. To our knowledge, this is the first report of a mitochondrial fission defect caused by DNM1L deficiency in humans.