Table 1: Pharmacology of GABA. The therapeutic targets, mechanisms of action, final effects on GABAergic transmission and pharmacological agents can be observed.
3-APMP: 3-aminopropyl(methyl)phosphonic acid; 3-APPA: 3-aminopropylphosphonic acid; BZD: benzodiazepines; GABA-T: GABA transaminase; GAD: glutamate decarboxylase enzyme; GAT: GABA transporter; IPSP: inhibitory postsynaptic potential.
TARGET TYPE MECHANISM EFFECT DRUGS REFERENCES
GABA SYNTESIS (GAD) Blocker Reduces GABA synthesis Reduces inhibitory tone Hidracines, valproic acid. [32,69]
Activator Reactive synthesis of GABA Reduces excitatory tone Piridoxine. [32,69]
TRANSPORT (GAT) Blocker Prevents GABA reuptake Increase inhibitory tone Vigabatrin, valproate, tiagabine, diaminobutyric acid, nipocotic acid and guvacine [32,51,52,53,69]
DEGRADATION (GABA-T) Inhibitor Blocks GABA degradation Increase inhibitory tone Vigabatrine, valproic acid. [70]
GABA-A RECEPTOR Agonist Increases chlorine entry by GABA-A receptor Inhibition (rapid IPSP). Increase inhibitory tone. BZD, barbiturates alcohol, neurosteroids, muscimol, abecarnil, topiramate. [17,23,25,27,28,29,32,48,49,61,64,65,66,69,71,72,77,82,89]
Antagonist Decreases chlorine permeability. Reduces inhibitory tone Excitatory tone predominates Picrotoxin, bicuculline, pentylenetetrazole, flumazenil. [23,27,29,65,66,69,71,72]
GABA B RECEPTOR Agonist Increases potassium output postsinapsis
Reduces calcium entry presynapsis		 Inhibition (slow IPSP) Reduces
neurotransmitter release		 Baclofen, 3-APPA, 3-APMA. [10,15,16,17,18,32,37,54,65,66,69,73,74,86,90]
Antagonist Reduces inhibitory tone Excitatory tone predominates Saclofen, ácido amino-valérico. [15,16,17,18,19,65,66,69,86]