WASHINGTON, D.C. November 3, 2021 — Social isolation rewires the brain in myriad ways, potentially leading to anxiety, depression, addiction, and other behavioral changes. The findings were presented at Neuroscience 2021, the annual meeting of the Society for Neuroscience and the world’s largest source of emerging news about brain science and health.
Humans are a highly social species who crave social contact for their well-being. Loneliness induced by social isolation can cause significant neurological and behavioral changes that may lead to health issues. Given the widespread experience of loneliness during the COVID-19 pandemic, there is a need to better understand and prevent the long-term effects of social isolation. Scientists are just beginning to understand these changes and hope to find ways to curb their negative effects.
Today’s new findings show:
- Young mice exposed to chronic social isolation demonstrated a long-term deficit in social recognition and an altered circuit between the prefrontal cortex and nucleus accumbens (Yong-Seok Lee, Seoul National University College of Medicine).
- Social isolation in adolescent mice led to increased cocaine use and relapse rates, as well as sex-dependent structural changes in the prefrontal cortex and nucleus accumbens (Lisa A. Briand, Temple University).
- Social isolation in young rats led to an increase in weight, anxiety, and dopamine release in the nucleus accumbens, but exercise mitigated anxiety and weight gain (Enrique U. Pérez-Cardona, University of Puerto Rico at Carolina).
- Lower social rank in mice is predictive of greater alcohol intake, but social isolation increases intake for all mice — regardless of rank — and increases the excitability of the basolateral amygdala (Reesha R. Patel, Salk Institute for Biological Studies).
- A socially monogamous prairie vole model mimicked human responses after the loss of a partner; these behavioral changes may be linked to disturbances in the brain’s oxytocin system (Adam S. Smith, University of Kansas).
“This research shows that social isolation impacts many brain regions and affects many different behaviors, resulting in increased risk for disease,” said Alexa H. Veenema, the director of the Neurobiology of Social Behavior Laboratory and an associate professor at Michigan State University. “The pandemic has had a tremendous effect on our mental health. This research will provide us with insights about which specific neural circuits mediate the behavioral effects induced by social isolation. We can then find ways to restore these neural circuits, counteracting the consequences of social isolation”
This research was supported by national funding agencies including the National Institutes of Health and private funding organizations. Find out more about social isolation on BrainFacts.org.
Social Isolation Press Conference Summary
- Social isolation affects multiple brain regions and behaviors.
- Exercise may mitigate some of the negative effects of social isolation.
- Social isolation is associated with changes to the prefrontal cortex, nucleus accumbens, and amygdala, as well as the dopamine and oxytocin systems.
- Social isolation primes the brain for substance abuse by restructuring neural circuits.
Impact of Social Isolation on the Prefrontal-nucleus Accumbens Circuit Critical for Social Recognition in Mice
- Young, socially deprived mice showed significant impairments in their recognition of other mice, which lasted into adulthood and did not improve even after a month of resocializing.
- Activating neurons within the prefrontal cortex/nucleus accumbens circuit restored social abilities in deprived mice, implicating the circuit in social recognition.
Post-weaning Social Isolation Alters Addiction-like Behaviors and Synaptic Plasticity in the Nucleus Accumbens and Prefrontal Cortex: Role of Sex and Neuroimmune Signaling
- Adolescent social isolation increases cocaine seeking in adult male and female mice.
- Biological sex moderated the impact of adolescent social isolation on neuronal complexity, with male mice showing increases in the nucleus accumbens and female mice exhibiting increases in the prefrontal cortex.
- Blocking the activity of microglia during adolescence partially reversed the neurological effects of social isolation.
Exercise as an Intervention to Minimize the Effects of Social Isolation on Anxiety
- Young rats isolated for 10 days gained weight, became more anxious, and had a blunted dopamine response in their nucleus accumbens.
- Isolation-induced anxiety and weight gain were curbed in rats that exercised five days a week for five weeks on a treadmill.
Amygdala-cortical Circuit Determinants of Social Isolation-induced Alcohol Consumption
- Adult mice that ranked low in their social circles drank more than their higher-ranking cage mates.
- Social isolation increased alcohol consumption and neural excitability in the basolateral amygdala in all mice, regardless of rank.
- Artificial stimulation of the basolateral amygdala led to increased alcohol, but not water, consumption.
The Role of Pair Bonding and Oxytocin Receptor Expression in Partner-seeking Behavior During Loss in Male Prairie Voles
- In a study where socially monogamous voles were separated from their social partner over the course of two weeks, male voles with a strong bond demonstrated symptoms resembling anxiety and yearning.
- Oxytocin receptor expression may help reveal how the brain processes the loss of a relationship.
About the Society for Neuroscience
The Society for Neuroscience is the world’s largest organization of scientists and physicians devoted to understanding the brain and nervous system. The nonprofit organization, founded in 1969, now has nearly 37,000 members in more than 90 countries and over 130 chapters worldwide.