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Maria Stella Valle

Publications and source records attributed to Maria Stella Valle.

2 recordsLinked to original sources

Cerebellar encoding of limb position.

In this paper, we review single and multijoint studies that, over the years, have provided insight on the cerebellar encoding of limb spatial position. In particular, we present support to the idea that the cerebellum integrates signals from multiple sources to encode global limb parameters. Then, we highlight the result of recent studies that analyzed quantitatively the relationships between limb end-point position and cerebellar activity. These findings suggest that the cerebellum may share with other central sensory-motor structures an anisotropic representation of limb position characterized by a strong bias along the anteroposterior axis. Finally, we speculate that this anisotropy may also subtend an internal representation of limb mechanics.

Animals↗

Anisotropic representation of forelimb position in the cerebellar cortex and nucleus interpositus of the rat.

The relationship between the spatial location of limb and the activity of cerebellar neurons has received little attention and its nature still remains ambiguous. To address this question we studied the activity of Purkinje and nucleus interpositus cells in relation to the spatial location of rat forelimb. A computer-controlled robot arm displaced the limb passively across 15 positions distributed on a parasagittal plane. The limb was upheld for 8 s in each position, which was identified by the Cartesian coordinates of the forepaw. We selected the neurons whose activities were significantly modulated by forepaw position and found that the majority represented preferentially one spatial dimension of the Cartesian plane both in the cerebellar cortex and nucleus interpositus. In particular, the antero-posterior axis was best represented in cerebellar neuronal discharges. This result suggests that the intermediate part of the cerebellum might encode limb position by way of an anisotropic representation of the spatial coordinates of the limb end-point.

Action Potentials↗