Astrocytes Can Turn Toxic
Astrocytes usually play a helpful role in the brain. These glial cells facilitate neural connections and prune unnecessary ones. However, new research details how infection or trauma can render astrocytes toxic, leading to brain disorders. In a 2017 article in the journal Nature, researcher Shane A. Liddelow and colleagues describe how resting astrocytes can become harmful reactive astrocytes.
The researchers determined that reactive astrocytes are found in brain tissues following brain injuries, or in neurological disorders including Alzheimer’s, Parkinson’s, Huntington’s, amyotrophic lateral sclerosis (ALS), and multiple sclerosis. Liddelow and colleagues also determined that microglia play a role in transforming resting astrocytes into a subtype of harmful reactive astrocytes, dubbed A1 astrocytes, and that the latter secrete a neuron-killing toxin.
A1 astrocytes lose their ability to promote neuronal survival and to create new synapses. The researchers showed that blocking the formation of A1 astrocytes prevented certain neuron deaths, and they hope this finding will lead to new treatments for brain injuries and neurological disorders.
Editor’s Note: It is possible that A1 astrocytes are also induced in patients with bipolar disorder, post-traumatic stress disorder (PTSD), and schizophrenia, as well as head traumas and neurological disorders.