Umbral Del Dolor

REVISIÓN

149

R e v. Soc. Esp. Dolor 7: 149-156, 2000

Del umbral a la neuromatriz
R. Melzack

Melzack R. From the gate to the neuromatrix. Rev Soc Esp Dolor 2000; 7: 149-156.

SUMMARY
The gate control theory’s most important contribution to understanding pain was its emphasis on central neural mechanisms. The theory forced the medical and biological sciences to accept the brain asan active system that filters, selects and modulates inputs. The dorsal horns, too, were not merely passive transmission stations but sites at which dynamic activities (inhibition, excitation and modulation) o c c u r red. The great challenge ahead of us is to understand brain function. I have there f o re proposed that the brain possesses a neural network—the bodyself neuro m a t r i x — whichintegrates multiple inputs to produce the output patt e rn that evokes pain. The body-self neuromatrix comprises a widely distributed neural network that includes parallel somatosensory, limbic and thalamocortical components that subserve the sensory-discriminative, affectivemotivational and evaluative-cognitive dimensions of pain experience. The synaptic arc h i t e c t u re of the neuromatrix is de t e rmined by genetic and sensory influences. The “neuros i g n a t u re” output of the neuro m a t r i x — p a t t e rns of nerve impulses of varying temporal and spatial dimensions—is p roduced by neural programs genetically build into the n e u romatrix and determines the particular qualities and other properties of the pain experience and behavior. Multiple inputs that act on the neuromatrixprograms and contribute to the output neuro s i g n a t u re include, (1) sensory

inputs (cutaneous, visceral and other somatic re c e p t o r s ) ; (2) visual and other sensory inputs that influence the cognitive interpretation of the situation; (3) phasic and tonic cognitive and emotional inputs from other areas of the brain; (4) intrinsic neural inhibitory modulation inherent in all brainfunction; (5) the activity of the body’s stre s s - re g ulation systems, including cytokines as well as the endocrine, autonomic, immune and opioid systems. We have traveled a long way from the psychophysical concept that seeks a simple one-to-one relationship between injury and pain. We now have a theoretical framework in which a genetically determined template tor the body-self is modulated bythe powerful stress system and the cognitive functions of the brain, in addition to the traditional sensory inputs. © 1999 International Association for the Study of Pain. Published by Elsevier Science B. V. Key wor ds: Gate control theory. Neuromatrix. Neuro s i gn a t u re .

RESUMEN
La contribución más importante de la teoría de la regulación del umbral a nuestro conocimiento del dolor fue suhincapié en los mecanismos neurales centrales. Esa teoría obligó a las ciencias médicas y biológicas a concebir el cerebro como un sistema activo que filtra, selecciona y modula los estímulos. Por otra parte, las astas dorsales dejaron de ser estaciones de transmisión meramente pasivas para convertirse en lugares donde ocurrían actividades dinámicas (inhibición, excitación y modulación). El granreto que nos plantea el futuro es llegar a comprender el funcionamiento del cerebro. Por ello, he propuesto que el cerebro posee una red neural –en la neuromatriz de la conciencia corporal– que integra diferentes estímulos para producir el tipo de respuesta que provoca dolor. La neuromatriz de la conciencia corporal está formada por una red neural ampliamente distribuida y formada por componentesparalelos somatosensoriales, límbicos y talamocorticales que son responsables de las dimensiones senso-discriminativas, afectivo-motivacionales y evaluo-cognitivas de la experiencia del dolor. La arquitectura sináptica de la neuromatriz está determinada por factores genéticos y sensoriales. La respuesta “neuroespecífica” de la

Departamento de Psicología, McGill University Dr. Penfield Avenue,...