Aksonipäätteen

Aksonipäätteen, known in English as the axon terminal or synaptic bouton, is the specialized structure at the end of an axon. It is a critical component of a neuron, responsible for transmitting signals to other neurons or target cells, such as muscle or gland cells. This transmission occurs at a junction called a synapse.

The axon terminal contains numerous small sacs called synaptic vesicles, which are filled with neurotransmitters. When an electrical impulse, an action potential, arrives at the axon terminal, it triggers the release of these neurotransmitters into the synaptic cleft, the small gap between the axon terminal and the next cell. These neurotransmitters then bind to receptors on the postsynaptic membrane of the target cell, initiating a new signal in that cell.

The structure of the axon terminal is adapted for efficient neurotransmitter release. It often forms a bulbous expansion and is rich in mitochondria to provide the necessary energy for synaptic transmission. The precise shape and arrangement of axon terminals can vary depending on the type of neuron and its function. The communication facilitated by axon terminals is fundamental to all nervous system functions, from simple reflexes to complex cognitive processes.