Soluvälittäjä

Soluvälittäjä, also known as a neurotransmitter, is a chemical messenger that transmits signals across a chemical synapse from one neuron to another neuron, or from a neuron to a target cell such as a muscle cell or gland cell. This transmission allows for communication between nerve cells and is fundamental to the functioning of the nervous system.

When an electrical impulse, or action potential, reaches the end of a neuron (the axon terminal), it triggers the release of soluvälittäjä molecules into the synaptic cleft, the small gap between the two neurons. These molecules then diffuse across the cleft and bind to specific receptor proteins on the membrane of the receiving neuron (the postsynaptic neuron).

The binding of the soluvälittäjä to its receptor can have different effects on the postsynaptic neuron. It can either excite the neuron, making it more likely to fire its own action potential (excitatory soluvälittäjä), or inhibit it, making it less likely to fire (inhibitory soluvälittäjä). Some soluvälittäjä can also have modulatory effects, influencing the overall activity of the neuron and its response to other signals.

There are numerous types of soluvälittäjä, each with distinct roles. Examples include acetylcholine, which is involved in muscle contraction and learning; dopamine, associated with reward and motivation; serotonin, which affects mood and sleep; and glutamate, the primary excitatory soluvälittäjä in the central nervous system. The precise balance and function of these chemicals are critical for a wide range of physiological processes and behaviors.