A study at the University of North Carolina revealed a new role that glial cells — known informally as the brain’s glue — might play in creating traumatic memories.
The researchers found that rats experiencing trauma produce an inflammation protein in their hippocampus — the part of the brain crucial for memory formation and learning — which creates a strong memory, which they term ‘stress-enhanced fear learning’. Rather than nerve cells, the ones responsible for this inflammation are astrocytes — star-shaped glial cells that were previously known for “supporting” important brain functions.
In addition to this, they found that exposure to stress causes changes to “neural immune interactions, including astrocyte activity.”
The researchers gave rats a series of shocks painful enough to “make you curse.” One week later, the same rats were given a much milder shock , but remained on edge. In some rats, Jones and her colleagues inhibited astrocyte activity during the original shocks, which stopped the glial cells from releasing the inflammation protein. Those rats were less jumpy when exposed to the milder shock.
Studies like these are “changing how we think about the circuitry that’s involved in depression and post-traumatic stress disorder,” said neuroscientist Georgia Hodes of Virginia Tech in Blacksburg. “Everyone’s been focused on what neurons are doing. [This is] showing an important effect of cells we thought of as only being supportive.”
This study could lead to further investigation into the part that astrocytes and other glial cells play in the development and function of the brain and nervous system. We still have far to go before we truly understand the super-powered 3 pound of fat in our skulls.