This insight will permit rational exploration of links between GSK3ß → δ-cat and attenuated Kcc2/KCC2 gene expression and the resulting malfunction of inhibitory neurotransmission in chronic pain and several other relevant neurologic and psychiatric conditions, such as epilepsy, traumatic brain/spinal cord injury, Rett Syndrome, autism spectrum disorders, and perhaps Alzheimer’s disease and other neurodegenerative diseases69–77. This evidence concerns the gene SLC12A5 and Rett syndrome.