Neurohistology and Neuropathology Flashcards
what are Betz cells
Large pyramidal cells called Betz cells are seen in primary motor cortex.
in fifth layer of the grey matter in the PMC.
largest in the CNS sometimes reaching 100 µm diameter. represent about 10% of the total pyramidal cell in layer V
function of an endosome?
function: recycling of cell membrane
It is a compartment of the endocytic membrane transport pathway from the plasma membrane to the lysosome.
Molecules internalized from the plasma membrane can follow this pathway all the way to lysosomes for degradation, or they can be recycled back to the plasma membrane
significance of Entorhinal cortex
Profound loss of layer 2 entorhinal cortex neurons occurs in very mild Alzheimer’s disease.
The entorhinal cortex plays a crucial role connecting the neocortex and hippocambal formation and is affected severely likely contributing to memory impairment.
Which of the following statements about microglia is correct?
It constitutes 70% of glial population in brain
It is mainly responsible for myelination
It is mesodermal in origin
It is present outside brain and spinal cord
It is sensitive to sodium channel stimulation
Unlike macroglia (astrocytes and oligodendrocytes) and neurons, which are derived from neuroectoderm,
microglial progenitors arise from peripheral mesodermal (myeloid) tissue
Electrical synapses are seen in: Bone marrow Lungs Olfactory epithelium Retina Skin of vertebrates.
An electrical synapse is a mechanical and electrically conductive link between two abutting neurons that is formed at a narrow gap between the pre- and postsynaptic neurons known as a gap junction. Electrical synapses are abundant in the retina and cerebral cortex
Which area of the brain is involved in the pathophysiology of OCD Amygdala Hippocampus Limbic system Orbito frontal cortex- striatal circuit Papez circuit
The orbitofrontal cortex (OFC)-striatal circuit, which is important for motivational behavior, is assumed to be involved in the pathophysiology of obsessive- compulsive disorder (OCD) according to current neurobiological models of this disorder
which side is Planum temporale larger normally
The planum temporale shows a marked leftward volume asymmetry that is related to the degree of right-handedness; this is more marked in males (nearly 10 times difference in R vs. L)
macro and micro changes in Alzheimers
The macroscopic Enlargement of the lateral and third ventricles, global brain atrophy, r eduction in brain weight and sulcal widening.
Neuronal loss, senile plaques, neurofibrillary tangles, reactive astrocytosis and shrinking of dendritic branching
where are neurofibrillary tangles found?
NFTs are found in the
hippocampus (Ammons horn) Amygdala, parahippocampal gyrus, neocortex, locus coereleus, n. of meynert and Raphe nuclei.
Senile Plaques are found in the same sites as those of NFTs.
picks disease; pathological changes
Pick’s disease is associated with selective asymmetrical atrophy of the frontal and anterior temporal lobes.
The histological changes in Picks disease would include Pick’s bodies, neuronal loss and reactive astrocytosis
changes may be seen in the cerebral cortex, substantia niagra, locus coereleus and basal ganglia.
Pick bodies are round argyrophilic intraneuronal inclusions (tau and ubiquitin reactive)
Pick cells are swollen cortical pyramidal cells with loss of nissls substance
Hirano bodies also present
Question 9. Lewy bodies are eosinophilic, haloed, intra neuronal inclusions. They contain which of the following materials? Amyloid substance Dopamine metabolites Glial tissue Paired helical filaments Tau protein
Lewy bodies occassionally contain Tau protein, though when histologically stained, most of them appear tau negative.
Alpha synuclein, ubiquitin, protein neurofilaments, granular material, dense core vesicles and microtubule assembly proteins make up the most of Lewy bodies.
In Lewy body dementia, the density of Lewy bodies is much higher in the
cingulate gyrus,
parahippocampal gyrus and
temporal cortex.
what is punch drunk syndrome
Dementia pugilistica (DP) is a type of neurodegenerative disease that can affect around 15% of boxers who suffer concussions after 12-16 years of boxing on average.
Histological changes include
neuronal loss and neurofibrillary tangles.
Thinning of the corpus callosum,
perforation of the septum pellucidum
ventricular enlargement is also seen
MIcro and Macroscopic findings in huntingtons
- Small brain with reduced mass
- atrophy of the corpus striatum, particularly the caudate nucleus
- atrophy of the cerebral cortex, particularly the frontal lobe gyri
- Dilatation of the lateral and third ventricles.
Histological changes:
cerebral cortex and neuronal loss in the corpus striatum
astrocytosis in the affected regions.
Question 17. The pathological factor that correlates most with cognitive decline in Alzheimer's disease is Burden of diffuse plaques Burden of gliosis Burden of neuritic plaques Burden of neurofibrillary tangles Burden of vascular amyloid load
A staging scheme devised by Braak and Braak (1995) is widely used to describe the extent of tangle related abnormalities (distribution from entorhinal cortex to isocortex) in AD and correlates well with the severity of dementia. Stages V-VI operationally define AD.
burden of NFTs
wernickes pathology
Wernicke’s encephalopathy is characterized by degenerative changes including gliosis and small hemorrhages in structures surrounding the third ventricle and aqueduct
(i.e. the mamillary bodies,
hypothalamus,
mediodorsal thalamic nucleus***,
colliculi, and midbrain tegmentum),
as well as cerebellar atrophy.
