Close-up of a molecular model of prokaryotic GLIC synaptic receptor (Gloeobacter Ligand-gated Ion Channel, blue and grey) complexed with omega-3 fatty acid docosahexaenoic acid (DHA, yellow spheres). When a neurotransmitter binds to a channel, GLICs allow for ions to pass through a channel. However, when DHA binds to GLIC, it conforms the ion channel into a desensitised state. This is when an ion channel tends to close despite a neurotransmitter being bound to it. GLIC is in a desensitized state because the DHA molecule has bound to it at a site at the edge of the channel, near the M4 helix (blue), causing a change in its structure. This leaves the upper part of the channel open while the lower part is constricted and closed, enhancing channel desensitization. Understanding channel desensitization, could allow development of drugs that target desensitized ion channels.