The Aging GABAergic System and Its Nutritional Support

Figure 2

An image of a GABA A receptor, closed left image and open right image to ions, and its GABA and neurosteroid ligand/hormone binding sites. Extrasynaptic GABA A receptors primarily contribute to tonic inhibition. Neurosteroids, including progesterone, allopregnanolone, and DHEA, activate both postsynaptic and extrasynaptic receptors to enhance the phasic and tonic inhibition and thereby promote maximal net inhibition. The blue dots represent the GABA neurotransmitter molecules released from the vesicles of the GABA neuron synapse; the white dots represent chloride ion movement through the GABA A receptor. Abbreviations: GABA, γ-aminobutyric acid; DHEA, dehydroepiandrosterone; DHEAS, dehydroepiandrosterone sulfate; CL ion, Cl⁻ion. [35].