excitatoriskt

Excitatoriskt is a Swedish adjective meaning excitatory, describing something that increases excitation in neural, muscular, or other physiological systems. In scientific contexts it refers to processes, signals, or substances that raise the likelihood or intensity of activity in a target cell or tissue.

In neuroscience, excitatoriska synapser release neurotransmitters that depolarize the postsynaptic membrane, increasing the probability that an action potential will be generated. The principal excitatory neurotransmitter in the central nervous system is glutamate, which acts on ionotropic receptors such as AMPA, NMDA, and kainate, and on metabotropic receptors. At the neuromuscular junction, acetylcholine is a key excitatory transmitter. Activation of these receptors typically produces excitatory postsynaptic potentials (EPSPs) driven by Na+ and Ca2+ influx, which can summate temporally or spatially to trigger action potentials.

The concept of excitation is balanced by inhibition, mediated primarily by GABAergic and glycinergic synapses that produce inhibitory postsynaptic potentials. The balance between excitation and inhibition shapes neural network activity, plasticity, and information processing. Excitatory signaling also underpins synaptic plasticity mechanisms such as long-term potentiation (LTP), which is important for learning and memory.

Outside neuroscience, excitatoriskt can describe stimuli or drugs that increase arousal, alertness, or metabolic activity. Excessive excitation can be harmful, a situation known as excitotoxicity, where overactivation leads to neuronal injury or death, implicated in conditions like stroke and neurodegenerative diseases.

See also: excitatory postsynaptic potential, glutamate, acetylcholine, synaptic transmission, excitotoxicity.