neuromodulátor

Neuromodulátor is a term used in neuroscience to describe substances or mechanisms that modulate neural activity and synaptic transmission in ways that differ from fast, point-to-point neurotransmission. Neuromodulators typically influence the excitability of neurons and the strength of synaptic connections over longer timescales, and they often act diffusely through volume transmission rather than at a single synapse.

Endogenous neuromodulators include monoamines such as dopamine, norepinephrine, and serotonin; acetylcholine in particular circuits; neuropeptides like substance P and neuropeptide Y; purines such as adenosine and ATP; endocannabinoids; and gaseous transmitters such as nitric oxide. Most operate via metabotropic receptors, triggering second messenger cascades that alter ion channel conductance, receptor sensitivity, or gene expression, thereby changing network dynamics and plasticity. Release can be extrasynaptic or activity-dependent, enabling coordinated modulation across larger neural ensembles.

Roles of neuromodulators span attention, arousal, motivation, learning, mood regulation, pain perception, and sleep–wake cycles. They shape the gain and timing of neural circuits, influence plastic changes during experiences, and interact with classical neurotransmitters to produce context-dependent responses.

In medicine and research, the concept of neuromodulation also encompasses devices and techniques that adjust neural activity, such as deep brain stimulation, transcranial magnetic stimulation, and vagus nerve stimulation. These approaches aim to alter network function in conditions like depression, Parkinson’s disease, chronic pain, and epilepsy, complementing pharmacological strategies that target natural neuromodulators.