Neurovälittäjät

Neurovälittäjät, also known as neurotransmitters, are chemical messengers that transmit signals across a synapse from one neuron to another, or to a target cell such as a muscle cell or gland. They are essential for the functioning of the nervous system, enabling communication between nerve cells.

The process begins when an electrical signal, an action potential, reaches the axon terminal of a neuron. This triggers the release of neurovälittäjät stored in vesicles into the synaptic cleft, the small gap between neurons. These molecules then diffuse across the cleft and bind to specific receptors on the postsynaptic neuron or target cell. This binding can either excite or inhibit the postsynaptic cell, depending on the type of neurovälittäjä and receptor involved.

Common neurovälittäjät include acetylcholine, which plays a role in muscle contraction and memory; dopamine, associated with reward, motivation, and movement; serotonin, involved in mood, sleep, and appetite; and glutamate, the primary excitatory neurovälittäjä in the central nervous system. Gamma-aminobutyric acid (GABA) is the primary inhibitory neurovälittäjä.

Once their signal has been transmitted, neurovälittäjät are typically removed from the synaptic cleft through reuptake by the presynaptic neuron, enzymatic degradation, or diffusion. This rapid clearance is crucial for precise and controlled neural signaling. Dysregulation of neurovälittäjä systems is implicated in various neurological and psychiatric conditions, highlighting their vital role in maintaining nervous system health and function.