[Motor activity enablement by sensory stimuli in Parkinson's disease]. / Facilitación de la actividad motora por estímulos sensoriales en la enfermedad de Parkinson.

AIMS: In this paper we review the most significant studies that deal with the motor enablement experienced by patients with Parkinson's disease in the presence of external rhythmic auditory or visual signals; the different possible causes underlying this enablement are also discussed. DEVELOPMENT: The improvements to movement that can be achieved using external stimuli in patients suffering from Parkinson are well documented in the literature. This is why sensory stimulus has become one of the most important points of reference within the rehabilitative strategies that attempt to alleviate the motor difficulties these patients display. Yet, the neurophysiological mechanisms underlying this sensorial enablement have still to be determined. CONCLUSIONS: The data we currently have available allows us to consider this type of technique as a useful instrument for improving the motor autonomy of patients with Parkinson and which should be taken into account by health care professionals.

[The thalamus: a dynamic door to perception]. / El tálamo: una puerta dinámica a la percepción.

y dependent on the activity of our senses for our relationship with the outside world, we may consider the thalamus to be a key part of perception. DEVELOPMENT. Far from behaving as a simple relay station, the thalamic circuits represent the framework on which to build a truly dynamic biological filter which can select the messages to reach the cortex according to their relevance and the behavioural state of the person. Such filtering implies the participation of many neurotransmitters which represent as many different systems. Outstanding amongst these are the groups formed by acetylcholine and nitric oxide axons arising from the brainstem, and corticofugal fibers which are sent back from the cortex to the thalamus. CONCLUSIONS. In this paper we review the functional aspects of the thalamic control of information, particularly of the visual system, with reference to alterations derived from its malfunction.

El tálamo: una puerta dinámica a la percepción / The thalamus: a dynamic door to perception

Introducción. La mayoría de la información sensorial llega hasta la corteza cerebral tras pasar por el tálamo. Dado que dependemos críticamente de la actividad de nuestros sentidos para relacionarnos con el mundo exterior, podemos considerar el tálamo como una pieza clave en la percepción. Desarrollo. Lejos de comportarse con una simple estación de relevo, los circuitos talámicos representan la armazón sobre la que se construye un auténtico filtro biológico y dinámico capaz de seleccionar los mensajes que han de llegar a la corteza en función de su relevancia y del estado conductual del sujeto. Este filtrado implica el concurso de múltiples neurotransmisores que representan a otros tantos sistemas aferentes. De entre ellos resaltan el conjunto formado por la acetilcolina y el óxido nítrico, cuyos axones nacen en el tronco del encéfalo, y las fibras nerviosas que la propia corteza cerebral envía hacia el tálamo. Conclusión. En este trabajo revisamos los aspectos funcionales del control talámico de la información, centrándonos en el sistema visual, con referencias a las alteraciones derivadas de su mal funcionamiento (AU)