Glutamate, GABA & Neurosteroid Activation
Glutamate (L-glutamic acid) and GABA (gamma-aminobutyric acid) are, respectively, the principal excitatory and inhibitory neurotransmitters in the CNS and play a significant role in HPA axis function and mood . These two amino acid-based neurotransmitters account for over 50% of the synapses in the brain, while the monoamines (serotonin, norepinephrine and dopamine) account for only about 5% .
Glutamate is required for synaptic transmission and plasticity, and learning and memory. However, abnormal function of the glutamatergic system can lead to neurotoxicity, and has been implicated in the pathophysiology of several disorders, including amyotrophic lateral sclerosis (ALS), epilepsy, Huntington’s disease, Alzheimer’s disease, schizophrenia, depression and anxiety disorders .