välittäjäainemekanismi

Välittäjäainemekanismi refers to the process by which neurotransmitters transmit signals between neurons in the nervous system. This mechanism is fundamental to virtually all brain functions, including thought, emotion, movement, and sensation.

The process begins when an electrical signal, an action potential, reaches the axon terminal of a presynaptic neuron. This triggers the release of neurotransmitters, chemical messengers, into the synaptic cleft, the small gap between the two neurons. These neurotransmitters then diffuse across the cleft and bind to specific receptors on the postsynaptic neuron's dendrites or cell body.

The binding of neurotransmitters to their receptors can have one of two effects on the postsynaptic neuron. It can be excitatory, making the neuron more likely to fire an action potential, or inhibitory, making it less likely to fire. This excitation or inhibition is determined by the type of neurotransmitter and the type of receptor it binds to.

Once the signal is transmitted, neurotransmitters are quickly removed from the synaptic cleft through various mechanisms, such as enzymatic degradation or reuptake by the presynaptic neuron. This ensures that the signal is brief and precise, allowing for rapid and continuous communication within the nervous system. Dysregulation of the välittäjäainemekanismi is implicated in numerous neurological and psychiatric disorders.