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Caenorhabditis elegans in Computational Research
Published in Theodore B. Achacoso, William S. Yamamoto, AY's Neuroanatomy of C. elegans for Computation, 2022
Theodore B. Achacoso, William S. Yamamoto
381 neurons with 92 glial/support cells and 302 neurons with 56 glial/support cells comprise the male and hermaphrodite nervous systems, respectively. The general structure of the C. elegans nervous system is made up of two units. 20 cells of a nerve ring are contained in the pharynx, and is the central region of the neuropil in the animal. The other unit is composed of the rest of the neuropil, which are (1) a ventral cord, the main process bundle that emanates from the nerve ring, (2) a dorsal cord, axons of motor neurons that originate in the ventral cord and enter the dorsal cord via commissures, and (3) four sublateral processes that run anteriorly and posteriorly from the nerve ring (Figure 1.2). In this worm, neurons are grouped into the 9 identified nervous system ganglia.
Brain swelling, raised intracranial pressure and hypoxia-related brain injury
Published in Helen Whitwell, Christopher Milroy, Daniel du Plessis, Forensic Neuropathology, 2021
Dark neurons in contrast have the following attributes (Figure 12.16):A monotonous, often shrunken appearance.Basophilic with H&E staining, having a dark blue perikaryal and dendritic cytoplasm.Slight eosinophilia may be superimposed giving a dark blue-red tint with H&E staining stain.Apical dendrites may have an irregular, corkscrew-shaped appearance.The shrunken, dark-stained nucleus may be indistinct within the cell body since it blends into the compacted perikaryal cytoplasm.Nucleoli though still discernable.Affected neurons may be separated from adjacent neuropil, especially with paraffin embedded tissue and are often scattered among histologically normal neurons (Jortner 2006).
Degenerative Diseases of the Nervous System
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
James A. Mastrianni, Elizabeth A. Harris
Microscopic pathology shows: Numerous, large pale (achromatic) ballooned neurons in the basal ganglia and the motor and premotor cortex (layers III, V, and VI). These are intensely neurofilament protein positive (NFP+). These are not specific for CBD, but are found less prominently in PSP, Pick's disease, frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), and AD.Neuropil threads: numerous and widespread threadlike processes in gray and white matter in the cortex, cerebral white matter, internal capsule, striatum, thalamic fasciculus, cerebral peduncle, and pons (Figures 16.59–16.61).Globose NFTs in the substantia nigra, locus ceruleus, and raphe nuclei.Pick's body–like tau inclusions in the cortex (layers II and III).Astrocytic plaques in focal atrophic cortices.Coiled bodies in oligodendrocytes (tau-positive fibers coiled around nucleus).Corticospinal tract degeneration.
Centella asiatica prevents D-galactose-Induced cognitive deficits, oxidative stress and neurodegeneration in the adult rat brain
Published in Drug and Chemical Toxicology, 2022
Zeba Firdaus, Neha Singh, Santosh Kumar Prajapati, Sairam Krishnamurthy, Tryambak Deo Singh
Light microscopic examination of H & E stained brain sections of the Control group revealed normal architecture of the cerebral cortex (Figure 4(A)) without any significant histopathological alterations. The D-gal group showed several histological changes in the cerebral cortex region (Figure 4(B)) as compared to the Control group. Pyramidal cells were highly affected; cells were shrunken, irregular in shape with a hyperchromatic nucleus, eosinophilic to vacuolated cytoplasm, and moderate gliosis was apparent. Granular cells showed indistinct cellular margins, nuclear karyorrhexis, and karyolysis with prominent pericellular edema. Prominent vacuolation in the neuropil was observed. Stroma adjacent to the affected neuronal cells showed marked pericellular and perivascular edema, karyorrhectic debris, and focal areas of gliosis. All of these findings indicate neurodegenerative changes in the cortical area. The D-gal + CAE group showed noticeably more normal histology in the cerebral cortex area (Figure 4(C)) when compared to the D-gal group. In the D-gal + CAE group, most neuronal cells were intact and appeared healthy. Cells rarely exhibited pericellular edema, nuclear pyknosis, neuronal degeneration, atrophy, or focal gliosis. Neuroglial cells appeared similar to the Control group except that a few were darkly stained. Small focal areas of neuropil vacuolations were seen (Figure 4(C)) but to a markedly lesser extent than in the D-gal group.
Evidence for altered excitatory and inhibitory tone in the post-mortem substantia nigra in schizophrenia
Published in The World Journal of Biological Psychiatry, 2020
Samuel J. Mabry, Lesley A. McCollum, Charlene B. Farmer, Emma S. Bloom, Rosalinda C. Roberts
Using a Hitachi H-7650 transmission electron microscope, electron micrographs were taken with a Hamamatsu Orca-HR Digital Camera at 25,000× magnification. Photomicrographs were taken of the neuropil. For this analysis, we examined 701 photomicrographs (each photomicrograph equalled 40.96 µm2), 1623 axon terminals and 1034 mitochondria (Table 2). Synapses were identified as either type 1 excitatory (asymmetric) or type 2 inhibitory (symmetric) (Gray 1969). The terms asymmetric and symmetric are grammatical descriptions of synapses with a thick postsynaptic density or a thin postsynaptic density, respectively. In the present analysis, synapses were characterised by the thickness of the postsynaptic density, regardless of the presence of a presynaptic density. Thus, synapses with a thick pre- and postsynaptic density would be deemed to be excitatory even though grammatically they are symmetric. Synaptic density as well as the number of mitochondria within each axon terminal was calculated. Synaptic density and the number of mitochondria per axon terminal was compared between groups, as well as the number of mitochondria per terminal making a symmetric synapse, or an asymmetric synapse, and the number of each of these types of synapses. Those synapses with intermediate morphologies were only counted in the overall tally.
Modulation of brain insulin signaling in Alzheimer’s disease: New insight on the protective role of green coffee bean extract
Published in Nutritional Neuroscience, 2020
Hoda E. Mohamed, Mervat E. Asker, Nahla N. Younis, Mohamed A. Shaheen, Rana G. Eissa
The histopathological features of H and E stained hippocampus from all groups were illustrated in Fig. 5. The neurons of CA1 of the hippocampus of the NC group are composed of three layers; molecular, pyramidal, and polymorphic layers. The pyramidal cells had tightly packed pyramidal neurons with large rounded vesicular nuclei and long parallel cytoplasmic processes directed toward the molecular layer. The neuropil is composed of mostly of unmyelinated axons, dendrites, and glial cell. The nuclei of the neuroglia and blood vessels were observed. In FR-AD group, the nerve cells of the CA1 region of the hippocampus showed deeply stained acidophilic cytoplasm of some pyramidal cells (P). The nuclei are rather ill defined or fragmented, with a significant decline in the number of pyramidal cells. Some Pyramidal neurons with vesicular nuclei were also noticed. Congested blood vessels were also observed. Many dark cells were also seen around nerve cells.