presynaptic terminal

The presynaptic terminal is the part of a nerve cell (neuron) responsible for sending signals to other neurons or cells. Located at the end of the neuron's axon, it contains small sacs called synaptic vesicles filled with neurotransmitters, which are chemicals that transmit messages. When an electrical signal travels down the axon and reaches the presynaptic terminal, it triggers the release of these neurotransmitters into the synapse, the gap between neurons. This process is vital for communication within the nervous system, affecting everything from muscle movement to mood regulation.