neurotransmitterene

Neurotransmitterene are the chemical messengers used by neurons to transmit signals across synapses. They are synthesized in the presynaptic neuron, packaged into synaptic vesicles, and released into the synaptic cleft in response to an action potential. After release, they bind to specific receptors on the postsynaptic cell, producing rapid electrical or biochemical responses. Termination occurs through reuptake into the presynaptic neuron or surrounding glia, enzymatic degradation, or diffusion away from the synapse, enabling precise temporal control of signaling.

Neurotransmitterene can be classified by their effect on the postsynaptic cell as excitatory or inhibitory. They act via two broad receptor families: ionotropic receptors, which form ligand-gated ion channels mediating fast responses, and metabotropic receptors, which are G protein-coupled and typically produce slower, modulatory effects through second messengers. In addition to fast transmitters, many neurons release neuromodulators and neuropeptides that alter the probability of release or the strength of synaptic responses over longer timescales.

Examples of classical neurotransmitterene include glutamate and acetylcholine as excitatory signals in many circuits, and GABA and glycine as inhibitory signals in the CNS and spinal cord. Monoamines such as dopamine, norepinephrine, and serotonin, along with histamine, have modulatory roles. Other signaling molecules, including neuropeptides, endocannabinoids, and nitric oxide, expand the repertoire of communication at synapses.

Dysfunction or dysregulation of neurotransmitterene systems is implicated in a wide range of neurological and psychiatric conditions, and many drugs exert therapeutic effects by altering synthesis, release, receptors, reuptake, or degradation of these messengers.