Ultrastructural Pathology of Oligodendroglial Cells in Traumatic and Hydrocephalic Human Brain Edema: A Review.

Oligodendroglial cell changes in human traumatic brain injuries and hydrocephalus have been reviewed and compared with experimental brain edema. Resting unreactive oligodendrocytes, reactive oligodendrocytes, anoxic-ischemic oligodendrocytes, hyperthrophic phagocytic oligodendrocytes, and apoptotic oligodendrocytes are found. Anoxic-ischemic oligodendrocytes exhibit enlargement of endoplasmic reticulum, Golgi complex, and enlargement and disassembly of nuclear envelope. They appear in contact with degenerated myelinated axons. Hypertrophic phagocytic oligodendrocytes engulf degenerated myelinated axons exerting myelinolytic effects. A continuum oncotic and apoptotic cell death type leading to necrosis is observed. The vasogenic and cytotoxic components of brain edema are discussed in relation to oligodendroglial cell changes and reactivity.

Electron microscopy of astrocyte changes and subtypes in traumatic human edematous cerebral cortex: a review.

The astrocyte subtypes in moderate and severe human brain trauma complicated with subdural hematoma or hygroma are described. Clear and dense edematous and hypertrophic reactive astrocytes are distinguished in severe vasogenic brain edema. Swollen perineuronal astrocytes appear compressing and indenting dark, degenerated pyramidal and nonpyramidal nerve cells. Glycogen-depleted and glycogen-rich astrocytes also are seen. Reactive hypertrophic astrocytes exhibit increased amounts of dilated smooth and rough endoplasmic reticulum, microtubules, and gliofilaments. Perisynaptic astrocyte ensheathments of neuropil synaptic contacts are lost, and the perivascular astrocyte end-feet appear dissociated from the capillary basement membrane. The interastrocytary gap junctions appear fragmented.

Increased vesicular and vacuolar transendothelial transport in traumatic human brain oedema. A review.

The endothelial vacuolar and vesicular transports in traumatic human brain oedema have been reviewed and compared with experimental brain oedema in order to establish their role in both oedema formation and oedema resolution. Normal or "non-activated" and "activated" capillaries are found. The activated capillaries showed predominantly an enhanced abluminally orientated vesicular transport by means of small, medium and large uncoated and clathrin coated vesicles, as well as the presence of endothelial tubular structures. Activation of the endothelial nuclear zone is featured by the increased amount of micropinocytotic vesicles. Vesicles internalizing to the hypertrophic Golgi complex, lysosomes and multivesicular bodies are observed. The protein vacuolar transport is predominant in most cortical capillaries. A wide spectrum of endothelial cell mechanisms is observed increasing the vesicular and vacuolar transport, such as deep invaginations of the luminal surface, large coated vesicles, tubular structures, and transient and incomplete transendothelial channels formed either by chained plasmalemmal vesicles or elongated protein-containing vacuoles. Uncoated vesicles are seen surrounding lysosomes. Vesicular transport might be discriminated between abluminally orientated or transendothelial transport (oedema formation) and intraendothelial transport (oedema resolution) directed towards cell lysosomes to be degraded by lysosomal enzymes. The transendothelial passage via large vacuoles is mainly caused by macromolecular protein transport.

Confocal laser scanning microscopy and immunohistochemistry of cerebellar Lugaro cells.

The present paper shows by means of confocal laser scanning microscopy the immunoreactivity of rat cerebellar Lugaro cells for calbindin, synapsin-I, PSD-95, GluR1, CaMKII alpha, and N-cadherin. Lugaro cells were easily characterized by their location beneath Purkinje cells. Calbindin revealed immunoreactivity in the cell body, and the axonal and dendritic processes. Synapsin-I labelled the presynaptic endings on Lugaro cells. Synapsin-I and PSD-95 immunoreactivity demonstrated the localization of presynaptic and postsynaptic endings surrounding cell soma, corresponding to afferent extrinsic and intrinsic cerebellar fibers. GluR1 immunoreactivity of the soma and cell processes indicates that Lugaro cells have functional ionotropic glutamate receptors that regulate calcium levels. CaMKII alpha immunoreactivity of Lugaro cell soma and processes suggest its participation as a molecular switch for long-term information storage, and serving as a molecular basis of long-term synaptic memory. N-cadherin immunoreactivity was correlated with somato-somatic and somato-dendritic junctions between Lugaro cells and their synaptic connections.

Confocal laser scanning microscopy and immunohistochemistry of cerebellar Lugaro cells. / Confocal laser scanning microscopy and immunohistochemistry of cerebellar Lugaro cells.

The present paper shows by means of confocal laser scanning microscopy the immunoreactivity of rat cerebellar Lugaro cells for calbindin, synapsin-I, PSD-95, GluR1, CaMKII alpha, and N-cadherin. Lugaro cells were easily characterized by their location beneath Purkinje cells. Calbindin revealed immunoreactivity in the cell body, and the axonal and dendritic processes. Synapsin-I labelled the presynaptic endings on Lugaro cells. Synapsin-I and PSD-95 immunoreactivity demonstrated the localization of presynaptic and postsynaptic endings surrounding cell soma, corresponding to afferent extrinsic and intrinsic cerebellar fibers. GluR1 immunoreactivity of the soma and cell processes indicates that Lugaro cells have functional ionotropic glutamate receptors that regulate calcium levels. CaMKII alpha immunoreactivity of Lugaro cell soma and processes suggest its participation as a molecular switch for long-term information storage, and serving as a molecular basis of long-term synaptic memory. N-cadherin immunoreactivity was correlated with somato-somatic and somato-dendritic junctions between Lugaro cells and their synaptic connections.

Correlative microscopy of Purkinje cells.

The Purkinje cell and their synaptic contacts have been described using (1) light microsocopy, (2) transmission and scanning electron microscopy, and freeze etching technique, (3) conventional and field emission scanning electron microscopy and cryofracture methods, (4) confocal laser scanning microscopy using intravital stain FM64, and (5) immunocytochemical techniques for Synapsin-I, PSD9-5, GluR1 subunit of AMPA receptors, N-cadherin, and CamKII alpha. The outer surface and inner content of plasma membrane, cell organelles, cytoskeleton, nucleus, dendritic and axonal processes have been exposed and analyzed in a three-dimensional view. The intramembrane morphology, in bi- and three-dimensional views, and immunocytochemical labeling of synaptic contacts with parallel and climbing fibers, basket and stellate cell axons have been characterized. Freeze etching technique, field emission scanning microscopy and cryofracture methods, and GluR1 immunohistochemistry showed the morphology and localization ofpostsynaptic receptors. Purkinje cell shows N-cadherin and CamKII alpha immunoreactivity. The correlative microscopy approach provides a deeper understanding of structure and function of the Purkinje cell, a new three-dimensional outer and inner vision, a more detailed study of afferent and intrinsic synaptic junctions, and of intracortical circuits.

Ultrastructural pathology of endothelial tight junctions in human brain oedema.

Cortical biopsies of patients with the diagnosis of complicated brain trauma, congenital hydrocephalus, brain vascular anomaly, and brain tumour are studied with the electron microscope using cortical biopsies of different cortical brain regions to analyze the alterations of endothelial junctions, and their participation in the pathogenesis of human brain oedema. In moderate oedema, most endothelial tight junctions are structurally closed and intact, while in some cases of severe oedema, the opening of tight endothelial junctions is observed. In very severe brain oedema, a considerable enlargement of interjunctional pockets of extracellular space is also seen suggesting that in highly increased cerebrovascular permeability, the endothelial junctions are open in their entire extent, and that an intercellular or paracellular route through interendothelial clefts for transferring haematogenous oedema fluid from blood to the capillary basement membrane and the brain parenchyma is formed, contributing to the formation of brain oedema. High intensity brain trauma, seizures, osmotic forces, hypoxic conditions, and alteration of tight junctions proteins would explain the opening of endothelial junctions in severe and complicated brain oedema. In congenital hydrocephalus, the capillary wall shows evident signs of blood-brain barrier dysfunction characterized by closed and open interendothelial junctions, increased endothelial vesicular and vacuolar transport, thin and fragmented basement membrane with areas of focal thickening, and discontinuous perivascular astrocytic end-feet. The perivascular space is notably dilated and widely communicated with the enlarged extracellular space in the neuropil, showing the contribution of damaged endothelial junction to the formation of interstitial or hydrocephalic brain oedema. Altered expression of tight junction proteins could cause a blood-brain barrier breakdown following brain injury and hypoxic conditions leading to brain oedema. The results are compared with those found in experimental brain oedema. Some controversial results are also described.

Correlative microscopy of Purkinje cells

The Purkinje cell and their synaptic contacts have been described using (1) light microsocopy, (2) transmission and scanning electron microscopy, and freeze etching technique, (3) conventional and field emission scanning electron microscopy and cryofracture methods, (4) confocal laser scanning microscopy using intravital stain FM64, and (5) immunocytochemical techniques for Synapsin-I, PSD9-5, GluR1 subunit of AMPA receptors, N-cadherin, and CamKII alpha. The outer surface and inner content of plasma membrane, cell organelles, cytoskeleton, nucleus, dendritic and axonal processes have been exposed and analyzed in a three-dimensional view. The intramembrane morphology, in bi- and three-dimensional views, and immunocytochemical labeling of synaptic contacts with parallel and climbing fibers, basket and stellate cell axons have been characterized. Freeze etching technique, field emission scanning microscopy and cryofracture methods, and GluR1 immunohistochemistry showed the morphology and localization of postsynaptic receptors. Purkinje cell shows N-cadherin and CamKII alpha immunoreactivity. The correlative microscopy approach provides a deeper understanding of structure and function of the Purkinje cell, a new three-dimensional outer and inner vision, a more detailed study of afferent and intrinsic synaptic junctions, and of intracortical circuits.

Correlative microscopy of Purkinje cells

The Purkinje cell and their synaptic contacts have been described using (1) light microsocopy, (2) transmission and scanning electron microscopy, and freeze etching technique, (3) conventional and field emission scanning electron microscopy and cryofracture methods, (4) confocal laser scanning microscopy using intravital stain FM64, and (5) immunocytochemical techniques for Synapsin-I, PSD9-5, GluR1 subunit of AMPA receptors, N-cadherin, and CamKII alpha. The outer surface and inner content of plasma membrane, cell organelles, cytoskeleton, nucleus, dendritic and axonal processes have been exposed and analyzed in a three-dimensional view. The intramembrane morphology, in bi- and three-dimensional views, and immunocytochemical labeling of synaptic contacts with parallel and climbing fibers, basket and stellate cell axons have been characterized. Freeze etching technique, field emission scanning microscopy and cryofracture methods, and GluR1 immunohistochemistry showed the morphology and localization of postsynaptic receptors. Purkinje cell shows N-cadherin and CamKII alpha immunoreactivity. The correlative microscopy approach provides a deeper understanding of structure and function of the Purkinje cell, a new three-dimensional outer and inner vision, a more detailed study of afferent and intrinsic synaptic junctions, and of intracortical circuits.(AU)

Ultrastructural pathology of cortical capillary pericytes in human traumatic brain oedema.

In human traumatic brain oedema pericytes exhibit remarkable oedematous changes, increased vacuolar and vesicular transport, transient transpericytal channels, and tubular structures demonstrating pericyte brain barrier dysfunction. They show nuclear invaginations, actin and myosin-like filaments, and coupled interaction with endothelial cells through the macula occludens. Some pericytes display hypertrophic and necrotic changes, and phagocytic capacity. Hypertrophic pericytes induce basement membrane splitting. Degenerated pericytes exhibit lacunar enlargement of endoplasmic reticulum, dense osmiophilic bodies, glycogen granules, vacuolization, oedematous Golgi apparatus, and pleomorphic mitochondria. Certain micropinocytotic vesicles are orientated to the Golgi complex and multivesicular bodies, suggesting that pericytes play some role in oedema resolution.

Submicroscopic pathology of human and experimental hydrocephalic cerebral cortex.

The ultrastructural pathology of cerebral cortex in human hydrocephalus is reviewed and compared with experimental hydrocephalus. Nerve cells show moderate and severe swelling. The neighboring neuropil exhibits notable enlargement of extracellular space, synaptic plasticity and degeneration, damage of myelinated axons, and myelination delay. The astrocytes display edematous changes and phagocytic activity. Glycogen rich- and glycogen-depleted astrocytes are observed. Some oligodendroglial cells exhibit normal morphology, and other exhibit hydropic changes. The capillary wall shows signs of blood-brain barrier dysfunction. The role of ischemia, oxidative stress, increased calcium concentration, activation of NMDA receptors, and disturbance of ion homeostasis are discussed in relationship with the fine structural alterations of hydrocephalic brain parenchyma.

Immunohistochemistry of GluR1 subunits of AMPA receptors of rat cerebellar nerve cells.

The localization of GluR1 subunits of ionotropic glutamate receptors in the glial cells and inhibitory neurons of cerebellar cortex and their association with the climbing and parallel fibers, and basket cell axons were studied. Samples of P14 and P21 rat cerebellar cortex were exposed to a specific antibody against GluR1 subunit(s) ofAMPA receptors and were examined with confocal laser scanning microscopy. GluR1 strong immunoreactivity was confined to Purkinje cell and the molecular layer. Weak GluR1 immunoreactivity was observed surrounding some Golgi cells in the granule cell layer. Intense GluR1 immunoreactivity was localized around Purkinje, basket, and stellate cells. Purkinje cells expressed strong GluR1 immunoreactivity surrounding the cell body, primary dendritic trunk and secondary and tertiary spiny dendritic branches. Marked immunofluorescent staining was also detected in the Bergmann glial fibers at the level of middle and outer third molecular layer. Positive immunofluorescence staining was also observed surrounding basket and stellate cells, and in the capillary wall. These findings suggest the specific localization of GluR1 subunits ofAMPA receptors in Bergmann glial cells, inhibitory cerebellar neurons, and the associated excitatory glutamatergic circuits formed by climbing and parallel fibers, and by the inhibitory basket cell axons.

Immunohistochemistry of GluR1 subunits of AMPA receptors of rat cerebellar nerve cells

The localization of GluR1 subunits of ionotropic glutamate receptors in the glial cells and inhibitory neurons of cerebellar cortex and their association with the climbing and parallel fibers, and basket cell axons were studied. Samples of P14 and P21 rat cerebellar cortex were exposed to a specific antibody against GluR1 subunit(s) ofAMPA receptors and were examined with confocal laser scanning microscopy. GluR1 strong immunoreactivity was confined to Purkinje cell and the molecular layer. Weak GluR1 immunoreactivity was observed surrounding some Golgi cells in the granule cell layer. Intense GluR1 immunoreactivity was localized around Purkinje, basket, and stellate cells. Purkinje cells expressed strong GluR1 immunoreactivity surrounding the cell body, primary dendritic trunk and secondary and tertiary spiny den dritic branches. Marked immunofluorescent staining was also detected in the Bergmann glial fibers at the level of middle and outer third molecular layer. Positive immunofluorescence staining was also observed surrounding basket and stellate cells, and in the capillary wall. These findings suggest the specific localization of GluR1 subunits ofAMPA receptors in Bergmann glial cells, inhibitory cerebellar neurons, and the associated excitatory glutamatergic circuits formed by climbing and parallel fibers, and by the inhibitory basket cell axons.

Immunohistochemistry of GluR1 subunits of AMPA receptors of rat cerebellar nerve cells

The localization of GluR1 subunits of ionotropic glutamate receptors in the glial cells and inhibitory neurons of cerebellar cortex and their association with the climbing and parallel fibers, and basket cell axons were studied. Samples of P14 and P21 rat cerebellar cortex were exposed to a specific antibody against GluR1 subunit(s) ofAMPA receptors and were examined with confocal laser scanning microscopy. GluR1 strong immunoreactivity was confined to Purkinje cell and the molecular layer. Weak GluR1 immunoreactivity was observed surrounding some Golgi cells in the granule cell layer. Intense GluR1 immunoreactivity was localized around Purkinje, basket, and stellate cells. Purkinje cells expressed strong GluR1 immunoreactivity surrounding the cell body, primary dendritic trunk and secondary and tertiary spiny den dritic branches. Marked immunofluorescent staining was also detected in the Bergmann glial fibers at the level of middle and outer third molecular layer. Positive immunofluorescence staining was also observed surrounding basket and stellate cells, and in the capillary wall. These findings suggest the specific localization of GluR1 subunits ofAMPA receptors in Bergmann glial cells, inhibitory cerebellar neurons, and the associated excitatory glutamatergic circuits formed by climbing and parallel fibers, and by the inhibitory basket cell axons.(AU)

The extracellular space in the edematous human cerebral cortex: an electron microscopic study using cortical biopsies.

In a vascular anomaly showing moderate edema, the extracellular space appeared apparently normal, exhibiting a membrane to membrane space of about 20 nm in width. In congenital hydrocephalus, this space appeared notably enlarged and occupied by an electron transparent, nonproteinaceous interstitial edema fluid, due to abnormal accumulation of cerebrospinal fluid. In brain trauma, the distended extracellular space contained either electron-lucid nonproteinaceous or electron-dense proteinaceous edema fluid. Hemorrhagic foci, fibrinoid material, and non-nervous invading cells, such as macrophages and monocytes, were also found. In brain tumors, the widened extracellular space showed electron-dense proteinaceous edema fluid and bundles of fibrinoid material. The enlarged extracellular space found in congenital hydrocephalus, vascular anomalies, brain trauma, and tumors is closely related to the clinical symptoms exhibited by the patients under study.

Blood-brain barrier ultrastructural alterations in human congenital hydrocephalus and Arnold-Chiari malformation.

Cortical biopsies of 13 patients with clinical diagnosis of congenital hydrocephalus, Arnold-Chiari malformation and hydrocephalus, and postmeningitis hydrocephalus were examined by transmission electron microscopy to study the damage of endothelial cells, basement membrane, astrocytic end-feet layer, and perivascular space. Capillaries from the parietal and frontal cortex showed increased vesicular and vacuolar transport, intact endothelial junctions, thin and immature basement membrane, swollen perivascular astrocytic end-feet layer, and enlarged perivascular space. In areas of severe oedema, open endothelial junctions, swollen basement membrane, absent perivascular astrocytic end-feet layer, enlarged perivascular space, and disrupted perivascular neuropil were observed. The electron microscopic findings demonstrated breakdown of the blood-brain barrier in all cases examined.

Structural patterns of injured mitochondria in human oedematous cerebral cortex.

PRIMARY OBJECTIVE: Cerebral cortical biopsies of 37 patients with clinical diagnosis of congenital malformations, brain trauma and tumours were studied to establish mitochondrial morphological alterations. METHODS AND PROCEDURES: Cortical biopsies obtained in the surgical room were immediately processed by conventional technique for transmission electron microscopy. RESULTS: Three injured mitochondrial morphological patterns were found: swollen clear, (SCM), swollen dense (SDM) and dark degenerated (DDM) mitochondria. SCM were predominantly found in traumatic brain oedema. SDM and DDM were frequently observed in sustained permanent ischaemia induced by brain tumours, vascular anomaly and congenital hydrocephalus. SCM exhibited low electron dense mitochondrial matrix, enlarged intracristal space and continuity of outer and inner mitochondrial membranes. SDM showed high electron dense matrix and swollen intact or fragmented cristae. DDM displayed overall high electron density of matrix and mitochondrial membranes. CONCLUSION: The injured mitochondrial patterns are related with nerve cell death and considered markers of lethal nerve cell injury.

Localization of synapsin-I and PSD-95 in developing postnatal rat cerebellar cortex.

The comparative localization of two prominent synaptic proteins, synapsin-I (Syn-I) and PSD-95, was investigated in slices of developing (P3-P21) rat cerebellar cortex using double- or triple-label fluorescence immunohistochemistry and confocal microscopy. During the first postnatal week, Syn-I and PSD-95 immunoreactive (IR) puncta were strongly concentrated in the Purkinje cell layer (PCL) where they circumscribed irregularly shaped PC somata, forming pericellular nests that likely correspond to early climbing fiber synapses. PSD-95 and Syn-I puncta also were found along the shafts and at the tips of growing PC dendrite branches labeled with calbindin. During the second postnatal week, synaptic puncta were lost from the PC layer, while many new puncta were added to the molecular layer (ML). At P10, about half of the PCs were circumscribed by PSD-95 or Syn-I puncta, whereas at P14 no PCs were circumscribed. By P14, PSD-95 and Syn-I became most strongly localized to many small puncta in the ML and to large clusters at mossy fiber rosettes in the glomerular layer (GL) where PSD-95 often encircled Syn-I clusters. Some large clusters in the GL contained only PSD-95 or Syn-I, but not both, suggesting differential growth or remodeling of pre- and post-synaptic structures. No PSD-95 staining of pre-synaptic terminal pinceau was observed during the first 3 weeks of postnatal development. Thus, in relation to PCs, there is a developmental shift in PSD-95 localization whereby, first, it is concentrated on PC cell bodies and short dendrites (P3-P7), then it is lost on PC cell bodies (P7-14) and becomes localized almost exclusively to PC dendrites (P14-P21).

Co-existence of anemia, vitamin A deficiency and growth retardation among children 24-84 months old in Maracaibo, Venezuela.

Iron deficiency anemia has been associated with alterations in child development and psychomotor function, being myelination and dopaminergic functioning especially vulnerable. Iron deficiency, at different ages, has different reversible and irreversible effects on CNS. Anemia has also been related to vitamin A deficiency (VAD) and growth retardation. The aim of the present paper was to determine the coexistence of micronutrient deficiency, iron and vitamin A, and macronutrient deficiency (growth retardation). The sample consisted of 202 Venezuelan children, aged 24-84 month old, (104 girls, 98 boys); Anemia, VAD and growth retardation was evaluated by means of blood hemoglobin concentration analysis, HPLC serum retinol (values <20 microg/dl reveal VAD) and height/age and weight/age Z scores (< or = - 2 SD express stunting and underweight). Prevalence of anemia was 38.11%; VAD, 21.78%; stunting, 14.36% and underweight, 9.40%. Anemia and VAD clustered in 7.92%; anemia + stunting or + underweight coexisted in 5.94% and 2.97%, respectively. Stunting and underweight clustered with VAD in 2.97% and 1.48%. The three-way combination with anemia was only seen with stunting in 0.99% of the sample. The prevalence of micronutrient deficiencies remain as significant public health problems which should be simultaneously treated as virtually independent, giving priority to infant, toddler and preschool age groups.

Glycogen-rich and glycogen-depleted astrocytes in the oedematous human cerebral cortex associated with brain trauma, tumours and congenital malformations: an electron microscopy study.

PRIMARY OBJECTIVE: The anaerobic mobilization of astrocyte glycogen in anoxic-ischemic regions of the oedematous human cerebral cortex is analysed. METHODS AND PROCEDURES: Seventeen cortical biopsies of patients with brain trauma, brain tumours and congenital malformations were examined by conventional transmission electron microscopy. RESULTS: Glycogen-rich and glycogen-depleted, clear or dense astrocytes cell bodies were observed in anoxic ischaemic regions of different brain cortical areas in perineuronal, neuropilar and perivascular localization. Glycogen-rich astrocytes showed clear or moderately dense cytoplasm and accumulation of both beta-type or monogranular glycogen granules and alpha-type or multigranular glycogen particles. Focal regions of translucent cytoplasm were observed in areas of glycogen degradation. Glycogen-depleted astrocytes exhibited a clear cytoplasm and scarce amount or absence of beta-type glycogen granules. Coexisting glycogen-rich and glycogen-depleted neuropilar astrocytic processes were observed in the vicinity of degenerated myelinated axons and degenerated axodendritic contacts. Glycogen-rich and glycogen-depleted perivascular astrocytic processes were also found surrounding injured and collapsed cerebral capillaries. CONCLUSION: The findings suggest astrocytic glycogen mobilization during anoxic and ischaemic conditions, revealing the important contribution of astrocytes on neuronal survival under conditions of energy substrate limitations.