Javier Cudeiro

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Neurons in the primary visual cortex (V1) respond in well defined ways to stimuli within their classical receptive field, but these responses can be modified by stimuli overlying the surrounding area. For example patch-suppressed cells respond to gratings of a specific orientation within their classical receptive field, but the response diminishes if the(More)
In a previous study, we have shown that the corticofugal projection to the dLGN enhances inhibitory mechanisms underlying length tuning. This suggests that the inhibitory influences deriving from the corticofugal feedback should exhibit characteristics that reflect the response properties of orientation-tuned layer VI cells. Here we report data obtained(More)
1. The influence of spatial frequency on the inhibitory component of the effects mediated by feedback from the visual cortex has been examined in X and Y cells in the A laminae of the feline dorsal lateral geniculate nucleus (dLGN). Experiments utilized a concentric, bipartite visual stimulus centered over the receptive fields of the cells studied. The(More)
Feedback projections are an integral part of the mammalian visual system. Although it is tempting to relegate them to a subsidiary role in visual processing, because their supposed latency and lag might appear to be unfavourable for an involvement in fast processing, this is a dangerous simplification. Certainly for the world in motion, feedback from higher(More)
The way in which the brain deals with sensory information relies not only on feedforward processing of signals from the periphery but also on feedback inputs. This is the case of the massive projection back from layer 6 in the visual cortex to the thalamus, for which, despite being the greatest single source of synaptic contacts, the functional role still(More)
This study has focused on how sensory stimulation affects gait in Parkinson’s disease (PD). The kinematic parameters of gait [cadence, step amplitude, velocity, coefficient of variation of stride time (CVstride-time), and the coefficient of variation of the step amplitude (CVstep-amplitude)] were analysed in 25 PD patients and 10 control subjects. Step(More)
The pulvinar nuclei of the thalamus are proportionately larger in higher mammals, particularly in primates, and account for a quarter of the total mass. Traditionally, these nuclei have been divided into oral (somatosensory), superior and inferior (both visual) and medial (visual, multi-sensory) divisions. With reciprocal connections to vast areas of(More)
Research in the fields of cellular communication and signal transduction in the brain has moved very rapidly in recent years. Nitric oxide (NO) is one of the latest discoveries in the arena of messenger molecules. Current evidence indicates that, in visual system, NO is produced in both postsynaptic and presynaptic structures and acts as a neurotransmitter,(More)
It has been suggested that sequential movements in patients with Parkinson's disease (PD) might be improved by the effects of external rhythmic cues. We studied spatiotemporal gait parameters and temporal gait variability in patients with PD and control subjects under different walking conditions in order to investigate whether rhythmic auditory cues could(More)
In the absence of a direct geniculate input, area 17 cells in the cat are nevertheless able to respond to visual stimuli because of feedback connections from area 18. Anatomic studies have shown that, in the cat visual cortex, layer 5 of area 18 projects to layer 5 of area 17, and layers 2/3 of area 18 project to layers 2/3 of area 17. What is the specific(More)