aksonipäätteestä

Aksonipääte, also known as the synaptic bouton or terminal bouton, is the specialized terminal end of an axon. It is a key component of the synapse, the junction where a neuron communicates with another cell, which can be another neuron, a muscle cell, or a gland cell. The primary function of the aksonipääte is to transmit signals from the presynaptic neuron to the postsynaptic cell.

Within the aksonipääte are numerous synaptic vesicles, small membrane-bound sacs filled with neurotransmitters. These neurotransmitters are chemical messengers that carry the signal across the synaptic cleft, the tiny gap between the presynaptic and postsynaptic cells. When an electrical impulse, or action potential, arrives at the aksonipääte, it triggers the influx of calcium ions. This calcium influx causes the synaptic vesicles to fuse with the presynaptic membrane and release their neurotransmitter contents into the synaptic cleft.

The released neurotransmitters then bind to specific receptors on the postsynaptic cell's membrane, initiating a response in that cell. This response can be excitatory, increasing the likelihood of the postsynaptic cell firing its own signal, or inhibitory, decreasing that likelihood. The aksonipääte also contains mitochondria to provide the energy needed for neurotransmitter synthesis and release, as well as various proteins involved in synaptic transmission and recycling of synaptic vesicles. The precise structure and function of aksonipäätteet can vary depending on the type of neuron and the neurotransmitters they release.