GABAvsPEA (Palmitoylethanolamide)

GABA binds to GABA-A receptors (ligand-gated Cl- channels with alpha1-6, beta1-3, gamma1-3 subunits) and GABA-B receptors (G-protein coupled, Gi/o mediated), reducing neuronal excitability through hyperpolarization. However, supplemental GABA has limited blood-brain barrier penetration due to absence of a dedicated transporter and rapid metabolism by GABA-transaminase and succinate semialdehyde dehydrogenase in periphery. The calming effects may be mediated through: (1) GABA-A and GABA-B receptors in the enteric nervous system (gut-brain axis) — vagal afferents project to the nucleus tractus solitarius and influence limbic regions; (2) small amounts crossing the BBB via paracellular leakage or in individuals with compromised barrier integrity; (3) peripheral effects reducing systemic stress markers (cortisol, heart rate variability). PharmaGABA (Lactobacillus fermentation product) may have better absorption via peptide-like transport or different pharmacokinetics.

PEA activates PPAR-alpha (peroxisome proliferator-activated receptor alpha), a nuclear receptor that heterodimerizes with RXR and downregulates pro-inflammatory gene expression (NF-kB target genes, COX-2, iNOS, TNF-alpha). It has an 'entourage effect' on the endocannabinoid system — it inhibits the degradation of anandamide by fatty acid amide hydrolase (FAAH) through allosteric modulation or substrate competition, and upregulates CB2 receptor expression on immune cells. This provides anti-inflammatory and analgesic effects without directly activating CB1/CB2. PEA also activates GPR55 and GPR119. It inhibits mast cell degranulation (reducing histamine, tryptase, and cytokine release) and reduces microglial activation in the brain (inhibiting Iba1 expression and pro-inflammatory cytokine production). PEA may also modulate TRPV1.