Ethanol consumption induces depression.

• Ethanol enhances the inhibitory action of GABA in the brain, mainly at the GABA_A receptor.

• GABA is the major inhibitory neurotransmitter in the CNS.—–>GABA_A receptors are ligand-gated chloride (Cl⁻) channels——>Ethanol acts as a positive allosteric modulator of the GABA_A receptor (does not replace GABA).—–>In presence of ethanol, GABA binding increases opening frequency of Cl⁻ channels.—–>Increased Cl⁻ influx → hyperpolarization of neuronal membrane.——>Hyperpolarization reduces neuronal excitability and firing.

• Result → CNS depression.