Pyridoxal Phosphate, GABA and Seizure Susceptibility

Pyridoxal-P plays a major role in the short term regulation of γ-aminobutyric acid (GABA) synthesis in brain, as the GABA-synthesizing enzyme glutamate decarboxylase (GAD) is regulated in part by a tightly controlled cycle that interconverts the hold- and apoenzyme. This mechanism explains the sensitivity of brain GABA levels to vitamin B6 deficiency and very likely contributes to the enhanced seizure susceptibility that is a prominent symptom of vitamin B6 deficiency in animals and humans.