Calm
GABA
Also searched as GABA.
You want it sufficient: adequate GABA tone quiets the mind and eases the way into sleep.
In depth
GABA — the brain's principal inhibitory neurotransmitter, the source of calm and restful sleep.
What drives it
Gut barrier increases it.
Strandwitz 2019, Nat Microbiol — human gut bacteria (e.g. Bacteroides) produce the inhibitory neurotransmitter GABA; germ-free animals show reduced luminal/serum GABA. PMID 30531975. Convergent and mechanistic: gut bacteria carry gad genes encoding glutamate decarboxylase and produce GABA from dietary glutamate. Bifidobacterium adolescentis is identified as a model human-gut GABA producer, with two high-producing strains found by in vitro screening of 82 strains, and Bacteroides GABA pathways confirmed by transcriptome analysis. Specific the B. adolescentis / mental-health link comes from in silico metagenomic correlation, described by the authors as an association — not an intervention. Shared caveats on this whole row: (1) the route to the brain is not free — gut-derived neurotransmitters reach targets via the bloodstream and must cross the blood-brain barrier; elevated plasma 5-HT can itself raise BBB permeability, temporarily letting plasma 5-HT enter the CNS, so the barrier is a variable not a constant. (2) much of this literature is association — the reviews state plainly that the association studies linking microbiota to depression did not provide evidence on aetiology. (3) The enteric nervous system hosts more than 30 neurotransmitters; any single arrow is one strand of a dense web. PMID 30531975
Social bonding hormone increases it.
blockade settles it: oxytocin injected into the paraventricular nucleus increased GABAergic neuronal activity and local GABA release, and GABA-A receptor antagonism hinders the anxiolytic effects of oxytocin — remove GABA-A and the oxytocin effect goes with it. Oxytocin also activates GABAergic transmission in the central amygdala. It is upstream of it. PMC7848088
The Two-Faced Peptide reduces it.
In central amygdala slices, superfusing dynorphin or the KOR agonist U69593 decreased evoked inhibitory postsynaptic potentials in a concentration-dependent manner, an effect prevented by the antagonist norBNI. The antagonist-alone result is the applied alone, norBNI increased GABAergic transmission, revealing a tonic endogenous activity at KOR. The receptor is already occupied; blocking it releases a brake that was always on. Paired-pulse analysis places the mechanism presynaptically. And the sign can invert with drug history: in cocaine-experienced animals the effects of KOR ligands on CeA GABA synapses switch, attributed to persistently elevated dynorphin altering KOR-coupled presynaptic signaling. This edge describes a naive brain. doi 10.1038/s41386-025-02226-9 · PMID 24157490 · PMC3773286
Endocannabinoid tone reduces it.
10.1038/35069076 — ,depolarization-induced suppression of inhibition (dsi) is the classical and original electrophysiological example of endocannabinoid function in the central nervous system. Mechanism, and it runs backwards: depolarization raises calcium in the postsynaptic cell, which produces and releases 2-AG, which diffuses retrogradely — postsynaptic to presynaptic — to activate CB1 receptors on the incoming terminal and suppress GABA release. The receiving neuron tells its own inhibitors to back off. The constitutive activity is powerful enough to produce silent inhibitory synapses. Region decides which transmitter is targeted, which matters for an anxiety map: in cortical circuits CB1 sits mainly on CCK basket cells regulating GABA (dsi) and only to a lesser extent on pyramidal cells regulating glutamate (dse). In the central amygdala the balance inverts — the major role of CB1 there is to broadly regulate glutamatergic transmission, with CB1 activation reliably reducing excitatory currents while effects on GABAergic transmission were more variable. doi 10.1038/35069076
Quiets overexcitation increases it.
10.1523/JNEUROSCI.2630-18.2019 — It is now. Glutamatergic input onto GABAergic interneurons is feedback and FEEDFORWARD inhibition - the basic microcircuit motif of cortex and hippocampus. Excitation recruits its own restraint; that is what makes a circuit rather than a runaway. Same fifteen-source co-citation base as its partner arm, which is not a measured step, and both arms carry that limit. doi 10.1523/JNEUROSCI.2630-18.2019
What it drives
It increases Sleep.
Gottesmann 2002, Neuroscience 111:231 — GABA-A receptor activation favors sleep; the target of every hypnotic drug class. PMID 11983310
It reduces Calm under stress.
GABA is the principal inhibitory neurotransmitter of the CNS and the direct target of anxiolytic pharmacotherapy; deficient GABAergic tone is central to the aetiology and treatment of anxiety disorders. PMC10845093
It reduces Stress-relapse axis.
10.3389/fpsyg.2020.588068 — ,Completes the chain oxytocin -> GABA -> CRF: oxytocin inhibits CRF mRNA expression in the hypothalamus, producing anti-stress and anti-anxiety effects — and the source is explicit that the inhibitory effect of oxytocin on CRF mRNA is not a direct one on CRF neurons. GABAergic neurons in the peri-PVN project into the PVN and inhibit CRF expression via GABA-A receptors. doi 10.3389/fpsyg.2020.588068
It reduces Mood (serotonin).
GABA inputs inhibit raphe 5-HT neuron firing — the brake does not only act downstream in the amygdala, it reaches the source of forebrain serotonin. And the loop closes back: the GABAergic afferents may express 5-HT1B receptors that inhibit GABA release, so serotonin can disinhibit its own drive; raphe 5-HT neurons additionally autoinhibit through 5-HT1A autoreceptors. Stress reaches this junction too: raphe 5-HT neurons express glucocorticoid receptors, and chronic corticosterone alters 5-HT7-receptor-mediated modulation of GABAergic transmission in the DRN — which is a further unchecked pair, hpa? serotonin. PMC6267141
It reduces Alertness chemical.
10.1177/0022034513505771 — ,the central amygdala provides substantial GABAergic projections to the locus coeruleus — a direct anatomical brake from the fear nucleus onto the noradrenergic alarm, with a large number of CeA neurons projecting to the LC. The routing is segregated, which matters: a large number of CeA neurons project to the LC whereas only a small number of medial amygdala cells project to the dorsal raphe, and none of the CeA OR MeA cells provided dual projections to both — the amygdala addresses norepinephrine and serotonin through separate cell populations, not one broadcast (S0006899318301732). doi 10.1177/0022034513505771
It increases Mood.
Drawn as half of a balance rather than a level. A review of treatment-resistant depression lists among its core mechanisms an imbalance between glutamate and GABA that impairs synaptic plasticity — not low GABA, not high glutamate, but the ratio failing to support plasticity. The ketamine mechanism puts GABA at the center: NMDA blockade acts on inhibitory GABAergic neurons, and it is their disinhibition that releases the glutamate burst. The antidepressant target is a GABAergic cell. a review synthesis in treatment-resistant depression, a selected population (20-30 percent of MDD), which may not describe first-episode illness. No measurement here establishes a simple dose-response. doi 10.3390/jox6040134 · PMC4803609
It reduces Memory chemical.
Not a static wire — A receptor population that moves with sleep pressure. The source studies dynamic changes in GABA-A receptors on basal forebrain cholinergic neurons following sleep deprivation and recovery. The inhibitory receptors sitting on the arousal cells are themselves regulated by how long you have been awake. The homeostatic logic is explicit: prolonged activity decreases excitability and prolonged inactivity increases it, mediated by reciprocal plastic changes in inhibitory transmission. This sits directly under two edges already drawn: the GABA → Sleep link and the Cholinergic → Sleep link, and the Cholinergic → Sleep link carries the NREM/REM conditional showing the basal forebrain is where the NREM effect is delivered. This edge names the receptor doing it. PMC1805759
It reduces Quiets overexcitation.
Excitation-inhibition balance is the most basic organising principle in the brain. GABA is the principal inhibitory transmitter and glutamate the principal excitatory one; GABAergic interneurons restrain glutamatergic output, and the ratio between them is what anxiolytics, anticonvulsants, anaesthetics and excitotoxicity are all about. The sign is drawn inhibitory on GABA restraining glutamatergic transmission, which is the standard direction — but the relationship is reciprocal and the map draws one arrow. The reverse arm (glutamate driving GABAergic interneuron activity as feedback inhibition) is real and is not drawn. That asymmetry is stated rather than hidden, as it is for GH and IGF-1 and for weight and leptin. PMC3677985
It increases Stress resilience.
10.1038/s41380-024-02835-8 — The aging outcome lists the thirteen hallmarks themselves, each mapped to its pathway and labeled with its hallmark number. (from the reviews of this outcome). Verbatim: “GABA might have alleviated the stress induced by the mental tasks”. doi 10.1038/s41380-024-02835-8 · PMID 22203366
It reduces Calm pain signaling.
The defining feature is that the pain is real and the tissue is not damaged: central sensitization manifests as hyperalgesia, allodynia, expanded receptive fields, and impaired endogenous pain inhibition, and in osteoarthritis the same phenomenon does not correlate with radiographic findings - severe pain may persist despite stable joint structure. The mechanism is a balance failure in both directions at once: in the dorsal horn there is excessive release of glutamate, ATP, and substance P, leading to activation of NMDA receptors - while at the same time descending inhibitory mechanisms, notably those mediated by GABA, ARE weakened. Too much excitation and too little inhibition. And mast cells carry a specific hypothesis: thalamic mast cells releasing histamine, IL-1-beta, IL-6, TNF, CGRP and substance P, either stimulating thalamic nociceptive neurons directly or via microglia. Stated by the authors as a hypothesis, not an established mechanism. The reviewers ARE blunt about the state of knowledge: the pathophysiology and etiopathogenesis remain largely unknown, and there is NO definitive pathogenesis except for altered central pain pathways. doi 10.3390/biomedicines12071543 · PMC6687840
It increases Alcohol recovery.
10.3389/fncir.2023.1218737 — Drawn from reviews of neighboring outcomes rather than from studies of this outcome itself, which is weaker evidence, and the map marks it so. doi 10.3389/fncir.2023.1218737
It increases Fear extinction.
Inhibitory gating within the amygdala by infralimbic input is the circuit substrate of extinction expression. doi 10.1111/j.1601-183X.2012.00801.x · PMC2787650
It reduces Neuronal overexcitation.
Inhibitory tone opposes the depolarization that lifts the magnesium block and admits calcium; GABAergic signaling is the counterweight to excitation. doi 10.1186/s40035-021-00278-7 · PMC8788129
Blends that modulate it
Each blend page names this pathway and carries the study behind its claim.
See it on the map
Open the causal map to follow this pathway upstream and downstream, arrow by arrow, each with its study.