One thing we have learned during the COVID pandemic is that social isolation can affect cognitive functions, as previous research has suggested. This motivated researchers to further investigate the effects of social isolation in the brain, particularly in astrocytes.
Social Isolation Triggers Astrocyte-Mediated Deficits in Learning and Memory
Astrocytes play a variety of roles in the brain, including supporting neuronal function, participating in synapse formation and function, releasing neurotransmitters, and forming the blood-brain barrier. In normal group living conditions, astrocytes facilitate and enhance circuit function and memory.
However, they found that during social deprivation, astrocytes in a region of the brain known as the hippocampus suppressed circuit function and memory formation. A broad implication is that astrocyte function is adapted to social experiences.
To further understand the mechanism by which astrocytes from socially isolated mice cause learning and memory deficits, the researchers examined calcium ions (Ca2+), which previous studies have shown play a central role in astrocyte-mediated learning and memory behaviors.
They assessed the effect of social deprivation on astrocyte Ca2+ activity and found that social isolation significantly increased it, particularly the activity associated with the Ca2+ channel TRPA1.
This, in turn, was followed by the release of the inhibitory neurotransmitter GABA, which disrupts neural circuits associated with memory and learning. Importantly, both pharmacological and genetic inhibition of TRPA1 reversed the physiological and cognitive deficits associated with social deprivation.
Although social isolation affects other brain cells as well, researchers are excited to discover that a specific manipulation of astrocytes is sufficient to reverse social isolation-induced learning and memory deficits in animal models.
These findings suggest a new role for astrocytes in brain physiology. The function of astrocytes is affected by changes in the environment and is reflected in the animal’s behavior. In this case, social interaction is believed to be good for astrocytes and therefore the brain.