Neurology and Neurosurgery

April 26, 2024

Microglia are highly dynamic and constantly survey the brain environment. They are known to dampen neuronal hyperactivity during seizures. But the functional significance of microglia-neuron interactions during hypoactive periods, such as anesthesia, is largely unknown.

Mayo Clinic researchers have demonstrated that microglia can transiently boost neuronal activity after anesthesia. As described in Nature Neuroscience, the researchers used in vivo two-photon imaging combined with electron microscopy in laboratory mice. Neuronal activity was observed at baseline, during 30 minutes of isoflurane anesthesia and during emergence from general anesthesia.

Key findings:

• During anesthesia, microglial processes enter into the synaptic cleft to shield GABAergic inputs.
• That action transiently promotes neuronal hyperactivity during emergence from anesthesia.

The researchers note that the discovery could help pave the way for innovative methods to address post-anesthesia complications. "If we can explore the role of microglia in various physiological states, such as sleep, we could apply this knowledge to improve patient care in clinical settings," says Koichiro Haruwaka, Ph.D., the study's lead author.

For more information

Haruwaka K, et al. Microglia enhance post-anesthesia neuronal activity by shielding inhibitory synapses. Nature Neuroscience. 2024;27:449.

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