Grey matter loss seen after COVID

Grey matter loss seen after COVID

Subject : Science & tech

Context : The loss of smell and taste, which is among the most common symptoms associated with coronavirus infection, is writ large in the brain, says a study that scanned brain images from a group of volunteers to compare changes before and after COVID-19.

Concept :

• The study, which is yet to be peer-reviewed, was able to paint a picture of a distinct loss of grey matter, in regions of the brain associated with smell and taste in those who had tested positive for the coronavirus compared to those who hadn’t.

Grey Matter & White Matter

• Cerebrum forms the major part of the human brain. A deep cleft divides the cerebrum longitudinally into two halves, which are termed as the left and right cerebral hemispheres.
• The hemispheres are connected by a tract of nerve fibres called corpus callosum.
• The layer of cells which covers the cerebral hemisphere is called cerebral cortex. The cerebral cortex is referred to as the grey matter due to its greyish appearance. The neuron cell bodies are concentrated here giving the colour.
• The cerebral cortex contains motor areas, sensory areas and large regions that are neither clearly sensory nor motor in function. These regions called as the association areas are responsible for complex functions like intersensory associations, memory and communication.
• Fibres of the tracts are covered with the myelin sheath, which constitute the inner part of cerebral hemisphere. They give an opaque white appearance to the layer and, hence, is called the white matter.