Misophonia

"The researchers also used whole-brain MRI scans to map participants’ brains and found that people with misophonia have higher amounts of myelination. Myelin is a fatty substance that wraps around nerve cells in the brain to provide electrical insulation, like the insulation on a wire. It’s not known if the extra myelin is a cause or an effect of misophonia and its triggering of other brain areas."

"We found that veterans with PTSD had a significantly greater degree of hippocampal myelination compared to matched, trauma-exposed veterans without PTSD. The degree of hippocampal myelination was also significantly and positively correlated with current PTSD symptom severity."

"Whatever the mechanism, it is significant that we found hints of maladaptive myelin development in humans with vulnerability to stress because: (i) maladaptive myelin formation has been implicated in other psychiatric disorders (Fields, 2008); (ii) Changes in myelination represents a form of plasticity that has a greater reach in the brain regions implicated in PTSD (i.e., amygdala, anterior cingulate, insula, and orbitofrontal region"

"In the central nervous system, myelin insulates and protects axons and facilitates the conduction of nerve impulses (Barkovich, 2000). Therefore, the loss of myelin can result in reduced nerve conduction velocity, reduced millisecond axonal precision, and reduced range of cortical synchrony. These, in turn, could impact the overall speed of mental processes, spike-timing dependent plasticity, and/or functional connectivity (Nave and Ehrenreich, 2014). However, having an excess of myelin, particularly in gray matter structures, may also have negative consequences. For example, there is evidence that myelin inhibits synapse formation and reduces plasticity in the central nervous system (Chen et al., 2000; McGee and Strittmatter, 2003; McGee et al., 2005)"