Depletion of particular brain tissue linked to chronic depression, suicide

Context

According to a recent study, there was a sharp fall in the density of a particular nerve cell known as Astrocytes, throughout the brain in the people who suicide.

About Astrocytes

• Astrocytes are a sub-type of glial cellsin the central nervous system.
• They are also known as astrocytic glial cells.
• In humans, a single astrocyte cell can interact with up to 2 million synapses at a time.
• Several forms of astrocytes exist in the central nervous system including fibrous (in white matter), protoplasmic (in grey matter), and radial.
• Astrocytes help in
  • forming the physical structure of the brain
  • secretion or absorption of neural transmitters
  • maintenance of the blood-brain barrier
    

Key-highlights of the finding

• Scientists found that the number of astrocytes, was much lower in brains of people who had died by suicide.
• The density was five times lower in the mediodorsal thalamus and caudate nucleus and half in the prefrontal cortex in the subjects who had died by suicides than those who had no psychiatric conditions till death.
• Astrocytes can strongly modulate most facets of neuronal activity, including neuronal firing, neurotransmitter synthesis, neurotransmitter reuptake and synaptic transmission.
• The human cerebral cortex has a larger volume and faster variety of astrocytes than that in mice. So, their role in the human brain will be much more significant.
• The research also noted that depression impacted the quantity of these nerve cells rather than their structure. It, however, doesn’t establish the reason behind this depletion of astrocyte volume.