Calms you down. It inhibits shit from interacting with your nervous system. Which is good.
Big technical explaination, I don't understand either but here it is for the Brainiacs.
Inhibitory synapses
The neurotransmitter at inhibitory synapses hyperpolarizes the postsynaptic membrane.
Example: gamma aminobutyric acid (GABA) at certain synapses in the brain. Binding of GABA
to GABA-A receptors on the postsynaptic neuron opens up ligand-gated chloride (Cl-) channels. This is a fast response - taking only about 1 millisecond.
to GABA-B receptors activates an internal G protein and a "second messenger" that leads to the opening of nearby potassium (K+) channels. As you might expect, this is a slower response, taking as long as 1 second.
In both cases, the resulting facilitated diffusion of ions (chloride IN; potassium OUT) increases the membrane potential (to as much as -80 mv). This increased membrane potential is called an inhibitory postsynaptic potential (IPSP) because it counteracts any excitatory signals that may arrive at that neuron.
A hyperpolarized neuron appears to have an increased threshold. Actually, the threshold voltage (about -50 mv) has not changed. It is simply a question of whether the depolarization produced by excitatory synapses on the cell minus the hyperpolarizing effect of inhibitory synapses can reach this value or not.
Hyperpolarization
Despite their name, some neurotransmitters inhibit the transmission of nerve impulses. They do this by opening
chloride channels and/or
potassium channels in the plasma membrane.
In each case, opening of the channels increases the membrane potential by
letting negatively-charged chloride ions (Cl-) IN and
positively-charged potassium ions (K+) OUT
This hyperpolarization is called an inhibitory postsynaptic potential (IPSP).
Although the threshold voltage of the cell is unchanged, it now requires a stronger excitatory stimulus to reach threshold.
Example: Gamma amino butyric acid (GABA). This neurotransmitter is found in the brain and inhibits nerve transmission by both mechanisms:
binding to GABA-A receptors opens chloride channels in the neuron.
binding to GABA-B receptors opens potassium channels
