Exzitatorische

Exzitatorische is a term used in neuroscience and physiology to describe properties, signals, or synapses that increase the probability that a postsynaptic neuron will fire an action potential. The core mechanism is depolarization of the postsynaptic membrane, typically produced by the influx of positive ions through ligand-gated ion channels after neurotransmitter binding.

In chemical synapses, excitatory transmission is commonly mediated by neurotransmitters such as glutamate in the central nervous system and acetylcholine at many neuromuscular synapses. These neurotransmitters bind to ionotropic receptors that are permeable to Na+ and Ca2+, generating excitatory postsynaptic potentials (EPSPs). EPSPs are graded, rapid, and can summate temporally or spatially to reach threshold at the axon hillock, triggering an action potential.

Glutamatergic signaling is a major example of exzitatorische activity in the brain. Glutamate receptors include AMPA receptors, which mediate fast depolarization, and NMDA receptors, which contribute to calcium influx and play a key role in synaptic plasticity, learning, and memory. Inhibitory signaling, by contrast, typically involves GABA or glycine and leads to hyperpolarization or shunting of the postsynaptic membrane.

Exzitatorische processes are essential for sensory perception, motor control, and cognitive function. They must be balanced with inhibitory activity to maintain stable neuronal network function; excessive excitatory activity can contribute to excitotoxicity and neuronal damage in pathological conditions.