Depletion of particular brain tissue linked to chronic depression, suicide: Study
Science & Technology
16th Feb, 2021
In a recent research, a common characteristic has been found in the brain structure of people who died by suicide. There was a sharp fall in the density of ‘Astrocytes’, a particular nerve cell throughout the brain.
What is Astrocytes?
- It is a type of supportive nerve cells, look like the end of a frayed rope.
- Astrocytes are highly heterogeneous neuroglial cells with distinct functional and morphological characteristics in different parts of the brain.
- They are responsible for maintaining a number of complex processes needed for a healthy central nervous system (CNS).
Key-highlights of the Study
- 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 nucleusand 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.
How reduction in astrocytes have negative effects?
- A reduction in astrocytes in the brain regions studied here may have negative effects becausethese brain regions make up a circuit thought to be important for decision making and emotional regulation, functions affected by depression
- With fewer astrocytes to support them, the neurons in this circuit may not function as well as they otherwise would.
- Abnormalities in the prefrontal cortex also seem to be connected to impulsivity, which may play a role in suicide in some cases.
Three regions of the brain that are considered to be responsible for emotion regulation — dorsomedial prefrontal cortex, dorsal caudate nucleus and mediodorsal thalamus — were the focus of the study.