Postmortem Material Research Articles

Senataxin mutations elicit motor neuron degeneration phenotypes and yield TDP-43 mislocalization in ALS4 mice and human patients.

Amyotrophic lateral sclerosis type 4 (ALS4) is a rare, early-onset, autosomal dominant form of ALS, characterized by slow disease progression and sparing of respiratory musculature. Dominant, gain-of-function mutations in the senataxin gene (SETX) cause ALS4, but the mechanistic basis for motor neuron toxicity is unknown. SETX is a RNA-binding protein with a highly conserved helicase domain, but does not possess a low-complexity domain, making it unique among ALS-linked disease proteins. We derived ALS4 mouse models by expressing two different senataxin gene mutations (R2136H and L389S) via transgenesis and knock-in gene targeting. Both approaches yielded SETX mutant mice that develop neuromuscular phenotypes and motor neuron degeneration. Neuropathological characterization of SETX mice revealed nuclear clearing of TDP-43, accompanied by TDP-43 cytosolic mislocalization, consistent with the hallmark pathology observed in human ALS patients. Postmortem material from ALS4 patients exhibited TDP-43 mislocalization in spinal cord motor neurons, and motor neurons from SETX ALS4 mice displayed enhanced stress granule formation. Immunostaining analysis for nucleocytoplasmic transport proteins Ran and RanGAP1 uncovered nuclear membrane abnormalities in the motor neurons of SETX ALS4 mice, and nuclear import was delayed in SETX ALS4 cortical neurons, indicative of impaired nucleocytoplasmic trafficking. SETX ALS4 mice thus recapitulated ALS disease phenotypes in association with TDP-43 mislocalization and provided insight into the basis for TDP-43 histopathology, linking SETX dysfunction to common pathways of ALS motor neuron degeneration.

Spatial orientation of the adult cochlea: rotation, tilt, and angle theta 3.

Quantitative description in adult crania of (1) angular orientation of the basal turn of the cochlea relative to the sagittal (termed "rotation") and Frankfort horizontal (termed "tilt") planes, and angle theta 3 [angular relationship of the line defined by the cochlea's spiral center and cochlear (round) window, to the cochlear window]; (2) orientation of the cochlea relative to the plane defined by the horizontal and vertical portions of the facial nerve; (3) orientation of the basal turn of the cochlea relative to the plane of the posterior semicircular canal; and (4) the association of these orientations with the extent of mastoid pneumatization. Postmortem material analysis. From 41 bequeathed anatomical ear-normal cadaveric cranial, high-resolution CT scans were performed of the five crania with the largest and the five with the smallest mastoids. Eleven points in three-dimensional Cartesian space were appointed and studied with the software program FIJI. The median angle values (and ranges) for right ears were: "rotation" 52° (range 47-61); and, "tilt" 84° (79-89). The planes of the cochlear basal turn and facial nerve approximated superimposition: median 15° (2-19). Angle theta 3 for right ears was median 40° (28-44). Bilateral symmetry was found for the relationships between the planes. However, no association of any planar relationship with mastoid pneumatization was suggested. Considering the range of angles found in clinically normal adult specimens, spatial orientation of the cochlea may explain some of the difficulties in implantation.

C9ORF72 repeat expansion causes vulnerability of motor neurons to Ca2+-permeable AMPA receptor-mediated excitotoxicity

Mutations in C9ORF72 are the most common cause of familial amyotrophic lateral sclerosis (ALS). Here, through a combination of RNA-Seq and electrophysiological studies on induced pluripotent stem cell (iPSC)-derived motor neurons (MNs), we show that increased expression of GluA1 AMPA receptor (AMPAR) subunit occurs in MNs with C9ORF72 mutations that leads to increased Ca2+-permeable AMPAR expression and results in enhanced selective MN vulnerability to excitotoxicity. These deficits are not found in iPSC-derived cortical neurons and are abolished by CRISPR/Cas9-mediated correction of the C9ORF72 repeat expansion in MNs. We also demonstrate that MN-specific dysregulation of AMPAR expression is also present in C9ORF72 patient post-mortem material. We therefore present multiple lines of evidence for the specific upregulation of GluA1 subunits in human mutant C9ORF72 MNs that could lead to a potential pathogenic excitotoxic mechanism in ALS.

Huntingtin Aggregation Impairs Autophagy Leading to Argonaute-2 Accumulation and Global MicroRNA Dysregulation

Many neurodegenerative diseases are characterized by the presence of intracellular protein aggregates resulting in alterations in autophagy. However, the consequences of impaired autophagy on neuronal function remain poorly understood. In this study, we used cell culture and mouse models of huntingtin protein aggregation, as well as post-mortem material from patients with Huntington's disease to demonstrate that Argonaute-2 (AGO2) accumulates in the presence of neuronal protein aggregates and that this is due to impaired autophagy. Accumulation of AGO2, a key factor of the RNA-induced silencing complex that executes microRNA functions, results in global alterations of microRNA levels and activity. Together these results demonstrate that impaired autophagy found in neurodegenerative diseases not only influences protein aggregation, but also directly contributes to global alterations of intracellular posttranscriptional networks.

Chapter 19 - Purification of cells from fresh human brain tissue: primary human glial cells

In order to translate the findings obtained from postmortem brain tissue samples to functional biologic mechanisms of central nervous system disease, it will be necessary to understand how these findings affect the different cell populations in the brain. The acute isolation and analysis of pure glial cell populations are common practice in animal models for neurologic diseases, but are not yet regularly applied to human postmortem brain material. The development of novel cell isolation techniques and methods for transcriptomic and proteomic analysis have made it possible to isolate and phenotype primary human cell populations from the central nervous system. The psychiatric program of the Netherlands Brain Bank has considerable experience with the purification of glial cells. This chapter will review the rapid isolation and phenotyping procedures for two major glia cell populations in the human brain, microglia and astrocytes, and will also discuss the potential for biobanking these cells, as well as the possible alternatives to cell isolations. The acute isolation of glial cells without culture-based adherence steps allows the analysis of glial alterations that underlie, or are the result of, disease neuropathology of the donor.

Follicle sinus complexes (FSCs) in muzzle skin as postmortem diagnostic material of rabid dogs.

Recently, we reported that follicle-sinus complexes (FSCs) in the muzzle skin are useful for postmortem diagnosis of rabid dogs. Here, we compared the sensitivity and specificity of detecting the viral antigen in the brain and FSCs of 226 suspected rabid dogs, and assessed whether the FSC harbored the virus genome and particles. The viral antigen was detected in 211 of 226 samples with 100% sensitivity and specificity. Viral RNA and particles were observed in the cytoplasm of Merkel cells (MCs). These results suggest that MCs are targets of virus infection and FSCs are useful material for diagnosing rabies.

Is it time to update the Recommendations of the Polish Society of Forensic Medicine and Criminology on the collection of post-mortem material for toxicological analysis?

Is it time to update the Recommendations of the Polish Society of Forensic Medicine and Criminology on the collection of post-mortem material for toxicological analysis?

Postmortem immunohistochemical alterations following cerebral lesions: A possible pathohistological importance of the β-dystroglycan immunoreactivity.

The frequency of cerebrovascular injuries raises the importance of their immunohistological investigation in postmortem materials. Most injuries involve the impairment of the blood-brain barrier. The barrier is maintained by the glio-vascular connections which break up following injuries. Some immunohistochemical alterations may refer to the impairment of the gliovascular connections. Laminin and the components of the dystroglycan complex show characteristic immunohistochemical alterations following various experimental injuries (stab wound, cryogenic lesion, arterial occlusions): immunoreactivity of β-dystroglycan, α-dystrobrevin and aquaporin 4 disappeared while that of utrophin and laminin appeared along the vessels, whereas α-syntrophin visualized the reactive astrocytes but not the resting ones. The aims of the present study were to investigate whether these post-lesion alterations: (i) are reproducible with immersive fixation, which is used in postmortem histology; (ii) are resistant to a postmortem delay before fixation; and (iii) are to be attributed to a direct effect of the lesion, or are mediated by processes occurring only in the living brain. Three models were investigated: (i) following lesions, some brains were fixed by transcardial perfusion, others by immersion; (ii) following lesions, the animals were decapitated and stored at room temperature for 8 or 16 h before fixation; and (iii) the lesions were performed after decapitation. Cryogenic lesions were performed by applying a dry ice cooled copper rod to the brain surface of ketamine-xylazine anesthetized rats. The immunohistochemical reactions were performed on free-floating sections cut with vibratome. Both immunoperoxidase and immunofluorescence methods were used. The fixation method - perfusive or immersive - did not change the post-lesion phenomena investigated. The postmortem delay did not influence the β-dystroglycan immunoreactivity, that is its lack delineated the area of the lesion. However, in the case of the other substances, various lengths of postmortem delay rendered the immunohistochemistry uninterpretable. The results suggest β-dystroglycan immunostaining could be applied in the neuropathology to detect cerebrovascular impairments.

5 Live Offspring Produced from Reproductive Material Recovered During the Annual Cull of Bison from Yellowstone National Park

Bison from Yellowstone National Park (YNP) have a unique genetic history that makes them a conservation priority for the species. Unfortunately, there is a high prevalence of the zoonotic disease brucellosis in the herd. Part of the management strategy for controlling the disease and herd size in YNP is an annual culling process. This culling may result in loss of valuable genetic material and, until now, has been a missed opportunity to recover and preserve those genetics. The goal of this project was to demonstrate the feasibility of producing healthy offspring from reproductive material collected during the nonbreeding season from bison postmortem and to determine effects of donor parameters, including sexual maturity and pregnancy status on IVF outcomes. Oocytes were collected from ovaries harvested from bison within 2 h of slaughter during winters of 2014 to 2017 for use in in vitro embryo production (IVP). Frozen-thawed semen from 7 YNP bulls collected via electroejaculation in vivo or from epididymal flushes postmortem was used for IVF. Embryos were produced using standard cattle IVP procedures. On Days 7, 7.5, and 8 of in vitro culture, embryos were assessed for developmental stage and quality, and Grade 1 and 2 embryos were vitrified on Cryotops® (Kitazato, Tokyo, Japan) in a two-step equilibration process. Embryos were then stored until the breeding season when they were warmed, cultured for 6 h, evaluated for survival, and transferred to healthy bison recipients. Data were analysed using a Student’s t-test. Age did not affect the mean number of oocytes collected from a mature female (n = 254) v. juvenile (n = 27; 24 ± 16 v. 24 ± 13), embryo cleavage rates (54 ± 24% v. 45 ± 24%), or the rate of blastocyst development (8 ± 12% v. 7 ± 8%, respectively). Pregnancy status did have a significant effect on the number of oocytes collected per female (pregnant 22 ± 15%, n = 258; nonpregnant 26 ± 20%, n = 82; P = 0.04) and the percent of oocytes that cleaved (pregnant 56 ± 23%, n = 189; nonpregnant 47 ± 24, n = 61; P = 0.005). No difference was detected in the percent of embryos that reached the blastocyst stage of development (pregnant 8 ± 10%, nonpregnant 8 ± 15%). In August 2016, 12 embryos were transferred singly or in pairs to 10 recipient bison synchronized using a standard synch protocol. Ten days following removal of the CIDR, embryos were transferred to recipient bison with a palpable corpus luteum. In spring of 2017, a healthy female calf was born to a recipient who had received 2 Grade-2 blastocysts as graded at the end of the 6-h incubation period. The genetic dam of the calf was a pregnant adult bison cow. This calf demonstrates that live offspring can be generated from oocytes collected from bison postmortem in the nonbreeding season. Although cleavage rates were higher with oocytes from pregnant bison, viable embryos were generated from nonpregnant adults and juvenile females, warranting continued collection of their oocytes and banking of resulting embryos. To our knowledge, this is the first bison calf produced by in vitro production using postmortem reproductive material.

Lessons learned about [F-18]-AV-1451 off-target binding from an autopsy-confirmed Parkinson\u2019s case

[F-18]-AV-1451 is a novel positron emission tomography (PET) tracer with high affinity to neurofibrillary tau pathology in Alzheimer’s disease (AD). PET studies have shown increased tracer retention in patients clinically diagnosed with dementia of AD type and mild cognitive impairment in regions that are known to contain tau lesions. In vivo uptake has also consistently been observed in midbrain, basal ganglia and choroid plexus in elderly individuals regardless of their clinical diagnosis, including clinically normal whose brains are not expected to harbor tau pathology in those areas. We and others have shown that [F-18]-AV-1451 exhibits off-target binding to neuromelanin, melanin and blood products on postmortem material; and this is important for the correct interpretation of PET images. In the present study, we further investigated [F-18]-AV-1451 off-target binding in the first autopsy-confirmed Parkinson’s disease (PD) subject who underwent antemortem PET imaging. The PET scan showed elevated [F-18]-AV-1451 retention predominantly in inferior temporal cortex, basal ganglia, midbrain and choroid plexus. Neuropathologic examination confirmed the PD diagnosis. Phosphor screen and high resolution autoradiography failed to show detectable [F-18]-AV-1451 binding in multiple brain regions examined with the exception of neuromelanin-containing neurons in the substantia nigra, leptomeningeal melanocytes adjacent to ventricles and midbrain, and microhemorrhages in the occipital cortex (all reflecting off-target binding), in addition to incidental age-related neurofibrillary tangles in the entorhinal cortex. Additional legacy postmortem brain samples containing basal ganglia, choroid plexus, and parenchymal hemorrhages from 20 subjects with various neuropathologic diagnoses were also included in the autoradiography experiments to better understand what [F-18]-AV-1451 in vivo positivity in those regions means. No detectable [F-18]-AV-1451 autoradiographic binding was present in the basal ganglia of the PD case or any of the other subjects. Off-target binding in postmortem choroid plexus samples was only observed in subjects harboring leptomeningeal melanocytes within the choroidal stroma. Off-target binding to parenchymal hemorrhages was noticed in postmortem material from subjects with cerebral amyloid angiopathy. The imaging-postmortem correlation analysis in this PD case reinforces the notion that [F-18]-AV-1451 has strong affinity for neurofibrillary tau pathology but also exhibits off-target binding to neuromelanin, melanin and blood components. The robust off-target in vivo retention in basal ganglia and choroid plexus, in the absence of tau deposits, meningeal melanocytes or any other identifiable binding substrate by autoradiography in the PD case reported here, also suggests that the PET signal in those regions may be influenced, at least in part, by biological or technical factors that occur in vivo and are not captured by autoradiography.

Striatal dopamine D1-type receptor availability: no difference from control but association with cortical thickness in methamphetamine users.

Chronic methamphetamine use poses potentially devastating consequences for directly affected individuals and for society. Lower dopamine D2-type receptor availability has been observed in striata of methamphetamine users as compared with controls, but an analogous comparison of D1-type receptors has been conducted only on postmortem material, with no differences in methamphetamine users from controls in the caudate nucleus and putamen and higher D1 receptor density in the nucleus accumbens. Released from neurons when methamphetamine is self-administered, dopamine binds to both D1- and D2-type receptors in the striatum, with downstream effects on cortical activity. Thus, both receptor subtypes may contribute to methamphetamine-induced alterations in cortical morphology and behavior. In this study, 21 methamphetamine-dependent subjects and 23 healthy controls participated in positron emission tomography and structural magnetic resonance imaging for assessment of striatal D1- and D2-type receptor availability and cortical gray-matter thickness, respectively. Although D2-type receptor availability (BPND) was lower in the methamphetamine group, as shown previously, the groups did not differ in D1-type BPND. In the methamphetamine group, mean cortical gray-matter thickness was negatively associated with cumulative methamphetamine use and craving for the drug. Striatal D1-type but not D2-type BPND was negatively associated with global mean cortical gray-matter thickness in the methamphetamine group, but no association was found between gray-matter thickness and BPND for either dopamine-receptor subtype in the control group. These results suggest a role of striatal D1-type receptors in cortical adaptation to chronic methamphetamine use.

Distribution of Non-Persistent Endocrine Disruptors in Two Different Regions of the Human Brain.

Non-persistent endocrine disrupting chemicals (npEDCs) can affect multiple organs and systems in the body. Whether npEDCs can accumulate in the human brain is largely unknown. The major aim of this pilot study was to examine the presence of environmental phenols and parabens in two distinct brain regions: the hypothalamus and white-matter tissue. In addition, a potential association between these npEDCs concentrations and obesity was investigated. Post-mortem brain material was obtained from 24 individuals, made up of 12 obese and 12 normal-weight subjects (defined as body mass index (BMI) > 30 and BMI < 25 kg/m2, respectively). Nine phenols and seven parabens were measured by isotope dilution TurboFlow-LC-MS/MS. In the hypothalamus, seven suspect npEDCs (bisphenol A, triclosan, triclocarban and methyl-, ethyl-, n-propyl-, and benzyl paraben) were detected, while five npEDCs (bisphenol A, benzophenone-3, triclocarban, methyl-, and n-propyl paraben) were found in the white-matter brain tissue. We observed higher levels of methylparaben (MeP) in the hypothalamic tissue of obese subjects as compared to controls (p = 0.008). Our findings indicate that some suspected npEDCs are able to cross the blood–brain barrier. Whether the presence of npEDCs can adversely affect brain function and to which extent the detected concentrations are physiologically relevant needs to be further investigated.

Whole-Genome Sequence of Streptococcus tigurinus Strain osk_001, Isolated from Postmortem Material.

ABSTRACTStreptococcus tigurinus was recently described as a novel species, and some strains are highly virulent. We detected S. tigurinus in infected tissue sampled by necropsy. In order to characterize and confirm the virulence of this species, whole-genome sequencing of the pure cultured bacterium was performed. We found that the strain has specific and unique genetic elements contained in highly virulent strains of S. tigurinus.

In vivo estimation of normal amygdala volume from structural MRI scans with anatomical-based segmentation.

Literature includes a number of studies using structural MRI (sMRI) to determine the volume of the amygdala, which is modified in various pathologic conditions. The reported values vary widely mainly because of different anatomical approaches to the complex. This study aims at estimating of the normal amygdala volume from sMRI scans using a recent anatomical definition described in a study based on post-mortem material. The amygdala volume has been calculated in 106 healthy subjects, using sMRI and anatomical-based segmentation. The resulting volumes have been analyzed for differences related to hemisphere, sex, and age. The mean amygdalar volume was estimated at 1.42cm3. The mean right amygdala volume has been found larger than the left, but the difference for the raw values was within the limits of the method error. No intersexual differences or age-related alterations have been observed. The study provides a method for determining the boundaries of the amygdala in sMRI scans based on recent anatomical considerations and an estimation of the mean normal amygdala volume from a quite large number of scans for future use in comparative studies.

An unpredicted aggregation-critical region of the actin-polymerizing protein TRIOBP-1/Tara, determined by elucidation of its domain structure

Aggregation of specific proteins in the brains of patients with chronic mental illness as a result of disruptions in proteostasis is an emerging theme in the study of schizophrenia in particular. Proteins including DISC1 (disrupted in schizophrenia 1) and dysbindin-1B are found in insoluble forms within brain homogenates from such patients. We recently identified TRIOBP-1 (Trio-binding protein 1, also known as Tara) to be another such protein through an epitope discovery and proteomics approach by comparing post-mortem brain material from schizophrenia patients and control individuals. We hypothesized that this was likely to occur as a result of a specific subcellular process and that it, therefore, should be possible to identify a region of the TRIOBP-1 protein that is essential for its aggregation to occur. Here, we probe the domain organization of TRIOBP-1, finding it to possess two distinct coiled-coil domains: the central and C-terminal domains. The central domain inhibits the depolymerization of F-actin and is also responsible for oligomerization of TRIOBP-1. Along with an N-terminal pleckstrin homology domain, the central domain affects neurite outgrowth. In neuroblastoma cells it was found that the aggregation propensity of TRIOBP-1 arises from its central domain, with a short "linker" region narrowed to within amino acids 324-348, between its first two coiled coils, as essential for the formation of TRIOBP-1 aggregates. TRIOBP-1 aggregation, therefore, appears to occur through one or more specific cellular mechanisms, which therefore have the potential to be of physiological relevance for the biological process underlying the development of chronic mental illness.

TRISOMY 21 CAUSES A DEFICIT IN LYSOSOMAL CATHEPSINS AND ALTERS APP/Aβ PROCESSING INDEPENDENTLY OF AN EXTRA COPY OF APP

Down syndrome (DS) is caused by trisomy of chromosome 21 (Hsa21) and increases the risk of Alzheimer disease (AD). People who have DS universally develop AD pathology by the age of 40 and the majority develop early-onset dementia (AD-DS). Three copies of the Hsa21 gene APP are sufficient to cause early-onset AD but how trisomy of other Hsa21 genes influences disease development is unclear. We analysed cathepsin activity in patient fibroblasts, post-mortem brain material from people who have DS and AD pathology and a novel mouse model of AD-DS (progeny of the cross of the Tc1 model of Hsa21 trisomy with the J20 APP transgenic model). To understand how changes in cathepsin activity may affect APP and Aβ processing in vitro and in vivo in our AD-DS animal model, we used a combination of pulse-chase analysis, western blotting, immunohistochemistry, ELISA, mass-spectrometry, enzymatic activity assays and in vivo Aβ clearance studies. Additionally we undertook behavioural phenotyping and an aging study of our mouse model of AD-DS to understand how changes in APP/Aβ processing due to trisomy of Hsa21 effect learning and aging. Here we show that triplication of Hsa21 sequences, other than APP, cause cysteine cathepsin deficits that result in failure to activate these proteases in DS. We successfully modelled these enzymatic changes in a novel AD-DS mouse model system, and found that they occur independently of gross-enlargement of the endo-lysosomes. Using our AD-DS mouse model, we show that trisomy of Hsa21 sequences, other than APP, also alter the metabolism of APP/Aβ. These changes decrease the soluble Aβ38/42 ratio and are associated with an increase in Aβ aggregation and deposition, and result in exacerbation of APP/Aβ-associated hyper-activity and specific deficits in two tests of short-term memory. We also show that the trisomy-associated changes in APP/Aβ metabolism we observe occur independently of alterations in α-, β- or γ-secretase activity or changes in the rate of extracellular Aβ-clearance in vivo. We propose that trisomy Hsa21-associated cathepsin deficits are a novel AD-DS pathomechanism that alter APP/Aβ processing and may contribute to the development of AD in people who have DS.

F-18]-AV-1451 binding correlates with postmortem neurofibrillary tangle Braak staging.

[F-18]-AV-1451, a PET tracer specifically developed to detect brain neurofibrillary tau pathology, has the potential to facilitate accurate diagnosis of Alzheimer's disease (AD), staging of brain tau burden and monitoring disease progression. Recent PET studies show that patients with mild cognitive impairment and AD dementia exhibit significantly higher in vivo [F-18]-AV-1451 retention than cognitively normal controls. Importantly, PET patterns of [F-18]-AV-1451 correlate well with disease severity and seem to match the predicted topographic Braak staging of neurofibrillary tangles (NFTs) in AD, although this awaits confirmation. We studied the correlation of autoradiographic binding patterns of [F-18]-AV-1451 and the stereotypical spatiotemporal pattern of progression of NFTs using legacy postmortem brain samples representing different Braak NFT stages (I-VI). We performed [F-18]-AV-1451 phosphor-screen autoradiography and quantitative tau measurements (stereologically based NFT counts and biochemical analysis of tau pathology) in three brain regions (entorhinal cortex, superior temporal sulcus and visual cortex) in a total of 22 cases: low Braak (I-II, n=6), intermediate Braak (III-IV, n=7) and high Braak (V-VI, n=9). Strong and selective [F-18]-AV-1451 binding was detected in all tangle-containing regions matching precisely the observed pattern of PHF-tau immunostaining across the different Braak stages. As expected, no signal was detected in the white matter or other non-tangle containing regions. Quantification of [F-18]-AV-1451 binding was very significantly correlated with the number of NFTs present in each brain region and with the total tau and phospho-tau content as reported by Western blot and ELISA. [F-18]-AV-1451 is a promising biomarker for in vivo quantification of brain tau burden in AD. Neuroimaging-pathologic studies conducted on postmortem material from individuals imaged while alive are now needed to confirm these observations.

The pathology associated with diabetic retinopathy

This review summarizes the pathological features of diabetic retinopathy. The lesions occurring in the diabetic retina have been described over many decades using descriptive and experimental approaches based on clinical studies on patients, human post-mortem material, animal models and various in vitro systems. We have also accumulated a wealth of knowledge about basic molecular mechanisms and key pathogenic processes that drive these abnormalities in diabetic retina. Despite these advances, there are still limited therapeutic options for diabetic retinopathy with those currently available only addressing late-stage disease. With a particular focus on the earlier stages of diabetes, there is growing appreciation the complex neuronal, glial and microvascular abnormalities which progressively disrupt retinal function. This is especially true from the perspective of the neurovascular unit during health and disease. Based on a strong appreciation of cellular and molecular pathology that underpins diabetic retinopathy, further advances are anticipated as we drive towards development of efficacious therapeutic options that can address all stages of disease.

Using Flipped Model And Drawing Tutorials To Teach Neuroanatomy In Graduate Certificate Program In Intraoperative Neuromonitoring

ObjectiveIn collaboration with partners in the healthcare industry, we have created a Graduate Certificate Program in Intraoperative Neuromonitoring that prepares students to be neuromonitoring clinicians in operating rooms. Neuromonitoring clinicians provide live feedback regarding the integrity and functionality of a patient's nervous system while undergoing surgical operations. Profound knowledge of neuroanatomy is significantly important for the clinicians in this field to allow better understanding of the nervous system and structures at risk during the operations that utilize neuromonitoring. Learning structures in the nervous system and their complicated connections could be challenging for students. Students struggle to memorize parts of the brain, their positions, and connections, and do not retain knowledge for a long time after the ending of the class.MethodsTo make learning engaging and effective we use a hybrid model for the course: Students watch brain dissection movies and drawing tutorials, followed by quizzes and assessments online. Subsequently, during class meetings, we discuss about the role of nervous system regions using case studies that illustrate common neuropathologies. Students are required to draw nervous system structures as they listen to the modules included in the online tutorial “Draw It to know It”. As a part of drawing tutorials, basic descriptions of case studies are included. During the class, student also use virtual cadavers on Sectra tables, which enable students to perform virtual dissections of the brain and spinal cord that replace the use of preserved postmortem human brain material, and discus in more details case studies.ResultsOur experience is that introductory online drawing tutorials help students to visualize three dimensional relationships of nervous system regions, and improved student engagement during class. However, when students were assigned to draw the complicated neuronal pathways before in class lecture, their cognitive skills and engagement were not improved.ConclusionIn conclusion, our hybrid model with introductory assignments and drawing tutorials serve students to build in‐depth knowledge during class. Balanced online and in class activities provides solid knowledge to the students in our program and prepares them to practice in the intraoperative neuromonitoring field.Support or Funding InformationSelf supporting program

Structural rearrangements of the cerebral cortex in children and adolescents

The cortical formations of the brain involved in visual functions (the occipital and temporo-parieto- occipital areas, the oculomotor area of the prefrontal cortex), as well as the motor cortex in the representation zone of the arm and the medial region of the frontal cortex adjacent to the limbic lobe, were studied in post-mortem material. The thickness of the cortex and cortical layer III, the sizes of pyramidal neurons, the specific volumes of neurons and intracortical vessels were studied in subjects of both sexes, from birth to the age of 20 years, at yearly intervals (103 observations) using histological techniques, computer morphometric and stereological analysis. The thickness of the cortex of the cerebral hemispheres was observed to intensively increase from birth to the age of 3 years in the occipital, temporo-parieto-occipital and prefrontal cortical areas involved in visual recognition processes. The increase in thickness of the cerebral cortex continues until the age of 6 in the occipital cortex and in the oculomotor area, until the age of 7 years in the temporo-parietooccipital area and the medial prefrontal area, and until the age of 8–9 years in the motor cortex. The sizes of pyramidal neurons increase until the age of 6 years in the motor cortex, until the age of 8 years on the medial surface of the frontal lobe, and until the age of 9–10 years in the temporo-parieto-occipital area and in the dorsolateral area of the prefrontal cortex. The specific volume of neurons and blood vessels in the cortex of the cerebral hemispheres decreases and the volume of intracortical fibers increases throughout the ascending ontogeny, which is manifested most intensively in the prefrontal cortex.