excitatoire

Excisatoire is a term used in biology and medicine to describe things that provoke or increase the excitation of neurons or muscles. In neuroscience, it refers to processes or substances that raise the probability that a neuron will fire an action potential.

In synaptic transmission, an excitatory synapse generates an excitatory postsynaptic potential (EPSP), depolarizing the postsynaptic membrane by opening ion channels permeable to sodium and, in some cases, calcium. The main excitatory neurotransmitter in the central nervous system is glutamate; at the neuromuscular junction, acetylcholine can also have an excitatory effect. The integration of EPSPs with inhibitory postsynaptic potentials (IPSPs) determines whether the threshold for triggering an action potential is reached.

Clinically and pharmacologically, the term excitatoire describes states or substances that promote neuronal activity. Excessive excitation can lead to excitotoxicity, a mechanism involved in neuronal damage during epilepsy, traumatic brain injury, and certain neurodegenerative diseases. Pharmacological agents described as excitatory may be therapeutic targets or require regulation to prevent hyperactivity.

Etymologically, the word derives from the Latin excitare and is commonly used in French scientific terminology to describe excitatory actions. The term is typically contrasted with inhibition, which refers to mechanisms that reduce the probability of triggering an action potential, including inhibitory neurotransmitters and receptors.