Social Isolation Can Prompt Learning and Memory Complications

A healthy social life is crucial to our livelihood. No matter our age, science has shown that it is imperative to connect with other individuals to diminish stress and generally refine our daily lives.

A new study by Baylor College of Medicine published in Neuron suggests a lack of social interaction leads astrocytes in our brains to become hyperactive, eventually subduing circuit information and memory abilities. Flipping astrocyte hyperactivity can assist memory functioning linked with social segregation.

Not enough social interaction can lead to memory, learning slippage, and more complications. Baylor College of Medicine's research team learned by testing animals during a period of social separation that astrocytes, a cell of the central nervous system, become hyperactive and repress brain circuit function and memory ability.

Through the study, the team found that hindering astrocyte hyperactivity can help with cognitive deficiency linked with social isolation. "One thing we have learned during the COVID pandemic is that social isolation can influence cognitive functions, as previous studies suggested," said a Baylor College graduate student co-first author Yi-Ting Cheng.

"This motivated co-first author Dr. Junsung Woo and me to further investigate the effects of social isolation in the brain, specifically in astrocytes," said Cheng.

Astrocytes are a part of the central nervous system that have numerous roles. They help neurons operate and take part in synapse formation and function, while also discharging neurotransmitters and creating a blood-brain barrier.

"Under normal group housing conditions, astrocytes facilitate and promote circuit function and memory," said Benjamin Deneen, Ph.D., professor, and the Russell J. and Marian K. Blattner Chair in Neurosurgery and part of the Center for Stem Cells and Regenerative Medicine.

"However, we found that during social deprivation, astrocytes in the brain region known as the hippocampus actually suppress circuit function and memory formation. The broad conclusion is that astrocyte function is tuned to social experiences."

To dig deeper into how hyperactive astrocytes in mice affect learning and memory complications, the team studied calcium ions (Ca2+), as prior research suggested they play a crucial part in astrocyte-linked learning and memory deficits.

"We evaluated the effect of social deprivation on astrocyte Ca2+ activity and discovered that social isolation greatly increased it, specifically the activity involving Ca2+ channel TRPA1. This, in turn, was followed by the release of the inhibitory neurotransmitter GABA that put a break on neural circuits involved in memory and learning," said Cheng.

He concluded that the research reveals how astrocytes play a novel role in brain physiology and how their actions are impacted by the environment. In the study, social interaction proved to be beneficial for astrocytes, leading to the brain’s advantage.