neuronaktivációs

Neuronaktivációs refers to the process by which a neuron becomes electrically excited and transmits a signal. This occurs when the neuron's membrane potential, the electrical difference across its membrane, reaches a certain threshold. This threshold is typically around -55 millivolts, though it can vary slightly.

The activation of a neuron is a complex interplay of ion channels. When a stimulus, such as neurotransmitters binding to receptors or sensory input, causes the neuron's membrane to depolarize (become less negative), voltage-gated sodium channels begin to open. Sodium ions (Na+) rush into the neuron, causing a rapid and significant increase in the membrane potential, making it positive. This rapid depolarization is known as the action potential.

Following the influx of sodium, voltage-gated potassium channels open, and potassium ions (K+) flow out of the neuron. This outward movement of positive charge repolarizes the membrane, bringing it back towards its resting potential. For a brief period, the membrane potential may become even more negative than the resting potential, a phase called hyperpolarization.

Once the action potential is generated, it propagates along the axon of the neuron, much like a wave. This electrical signal is the fundamental unit of communication in the nervous system, allowing for the transmission of information between neurons and ultimately controlling bodily functions and cognitive processes. The strength of a stimulus does not affect the amplitude of the action potential; instead, the frequency of firing indicates the intensity of the stimulus.