2.2 Histopathology of the nervous system
In the activity below you will examine sections from the nervous system in conditions in which neurons die. These are Alzheimer’s disease, dementia with symptoms of Parkinson’s disease, frontotemporal lobe dementia and cerebrovascular disease.
Open thein a new window or tab. Find Slides 6–14 in the ‘Week 4’ category.
Start with Slide 6. Slide 6 is from a normal cortex for comparison. The outer layer of the brain, the cortex, contains large numbers of neuronal cell bodies and appears as ‘grey matter’. Beneath the cortex are areas with a high proportion of axons and myelin-producing oligodendrocytes, which appear as ‘white matter’.
Next look at Slides 7 and 8. They are from the cortex of a person with Alzheimer’s disease. Slide 7 shows the loss of neurons from the outer layers of the cerebral cortex. Slide 8 is stained to show accumulation of the protein β-amyloid; the accumulation of the protein in discrete plaques is very evident.
Next look at Slides 9 and 10. They are from the midbrain of a person with dementia with Lewy bodies (DLB) and symptoms of Parkinson’s disease. In this condition neurons from particular regions of the brain, controlling movement, are selectively lost. In addition, intracellular accumulations of protein, termed Lewy bodies, are detected by an H&E stain (Slide 9). The Lewy bodies can be identified by immunohistochemical staining with antibodies that recognise the protein α-synuclein (Slide 10).
Next look at Slides 11 and 12. They show frontotemporal lobe dementia (FTLD). In this condition there is severe neuronal loss from the cortex (Slide 11) and neurons often have protein inclusions. However, unlike Alzheimer’s disease, amyloid plaques and tangles are absent. Slide 12 is a section from the spinal cord, which shows motor neuron loss.
Finally, look at Slides 13 and 14. They are from a patient who had cerebrovascular disease. Slide 13 shows areas of cell death caused by lack of an adequate blood supply (infarcts). In this case the condition is associated with thickening of the walls of the blood vessels, narrowing the vessel lumen and deposition of β-amyloid, a condition termed amyloid angiopathy (Slide 14).
Slides 7–14 were kindly loaned for imaging by Dr Andrew King and Dr Safa Al-Saraj from King’s College Hospital, London.