Excitatorische

Exzitatorische (excitatorische) neurotransmission refers to synaptic processes that increase the probability that a postsynaptic neuron will fire an action potential. These mechanisms typically produce depolarization of the postsynaptic membrane and are essential for enabling information flow within neural circuits.

The principal mediators of excitatorische signaling are excitatory neurotransmitters, most notably glutamate in the central nervous system. Glutamate acts on ionotropic receptors such as AMPA, NMDA, and kainate receptors, and on metabotropic receptors that can enhance excitatory signaling. Acetylcholine is another common excitatory transmitter at neuromuscular junctions and in certain brain circuits, acting through nicotinic receptors. The net effect of excitatorische transmission is to generate excitatory postsynaptic potentials (EPSPs), small depolarizations that can summate over time (temporal summation) and space (spatial summation) to reach the threshold for triggering an action potential.

Excitatorische signaling plays a central role in learning and memory, synaptic plasticity, and development. Long-term potentiation (LTP), a cellular mechanism underlying memory formation, involves sustained excitatory transmission and activity-dependent changes at glutamatergic synapses. However, excessive excitatorische activity can be harmful, contributing to excitotoxicity and neuronal injury in conditions such as stroke or traumatic brain injury.

In neural networks, excitatorische and inhibitory signaling are balanced to shape signal processing. Inhibitory transmission, mainly mediated by GABA and glycine, counteracts excitation to prevent runaway activity. Understanding excitatorische processes is fundamental to neuroscience, informing how information is encoded, transmitted, and modified in the brain.