Synapse with serotonin and melatonin
The picture shows a synapse. Synapses are the contact points between nerves and nerves or other cells. There are electrical and chemical synapses. The picture shows a chemical synpase. The upper part shows the terminal axon of a nerve cell, which contains vesicles with neurotransmitters, in this case serotonin. When an impulse arrives, the vesicles fuse with the membrane, releasing their neurotransmitters into the synaptic cleft. The cleft is very narrow, so that the transmitters get to the receptors of the postsynaptic density of the dendrite of the following cell, which causes a signal. Lack of serotonin causes depression or anxiety disorders. Melatonin is produced by the epiphysis out of serotonin. The hormone melatonin regulates e.g. the circadian rhythm.
