April 25, 2019

Immune ‘pruning’ in schizophrenia

Ariel Deutch and colleagues have discovered that overactive brain immune cells during adolescence may contribute to schizophrenia.

by Bill Snyder

(iStock)

Arguably the most replicated post-mortem finding in schizophrenia is the loss of dendritic spines from pyramidal cells in the brain’s prefrontal cortex, which is involved in decision-making, attention and moderating social behavior.

Pyramidal cells are cortical neurons that communicate with distant neurons. Dendritic spines are “protuberances” from the surface of the cell that receive incoming messages. Why so many dendritic spines are “pruned away” in schizophrenia, which usually is diagnosed in the late teen or early adult years, is not known.

Allyson Mallya, Ariel Deutch, PhD, and colleagues examined if microglia, immune cells in the brain that are different from those in the rest of the body, removed dendritic spines from the pyramidal cells in rats of adult, adolescent, or childhood age.

Reporting in the journal Cerebral Cortex, they found that microglia selectively removed dendritic spines from the pyramidal cells of adolescent rats. This suggests that excess microglial activity during adolescence may contribute to schizophrenia.

Deutch is the James G. Blakemore Professor of Psychiatry and Behavioral Sciences. This research was supported by grants from the National Institutes of Health (MH077298, HD015052).