%0 Journal Article
%T Peripheral facial nerve lesion induced long-term dendritic retraction in pyramidal cortico-facial neurons Retracci車n a largo plazo del 芍rbol dendr赤tico de neuronas piramidales c車rtico-faciales por lesiones perif谷ricas del nervio facial
%A Diana Urrego
%A Alejandro M迆nera
%A Julieta Troncoso
%J Biom谷dica
%D 2011
%I Instituto Nacional de Salud
%X Introduction. Little evidence is available concerning the morphological modifications of motor cortex neurons associated with peripheral nerve injuries, and the consequences of those injuries on postlesion functional recovery. Objective. Dendritic branching of cortico-facial neurons was characterized with respect to the effects of irreversible facial nerve injury. Materials and methods. Twenty-four adult male rats were distributed into four groups: sham (no lesion surgery), and dendritic assessment at 1, 3 and 5 weeks post surgery. Eighteen lesion animals underwent surgical transection of the mandibular and buccal branches of the facial nerve. Dendritic branching was examined by contralateral primary motor cortex slices stained with the Golgi-Cox technique. Layer V pyramidal (cortico-facial) neurons from sham and injured animals were reconstructed and their dendritic branching was compared using Sholl analysis. Results. Animals with facial nerve lesions displayed persistent vibrissal paralysis throughout the fiveweek observation period. Compared with control animal neurons, cortico-facial pyramidal neurons of surgically injured animals displayed shrinkage of their dendritic branches at statistically significant levels. This shrinkage persisted for at least five weeks after facial nerve injury. Discussion. Irreversible facial motoneuron axonal damage induced persistent dendritic arborization shrinkage in contralateral cortico-facial neurons. This morphological reorganization may be the physiological basis of functional sequelae observed in peripheral facial palsy patients. Introducci車n. Poco se sabe sobre las modificaciones morfol車gicas de las neuronas de la corteza motora tras lesiones en nervios perif谷ricos, y de la implicancia de dichos cambios en la recuperaci車n funcional tras la lesi車n. Objetivo. Caracterizar en ratas el efecto de la lesi車n del nervio facial sobre la morfolog赤a de las neuronas piramidales de la capa V de la corteza motora primaria contralateral. Materiales y m谷todos. Se reconstruyeron neuronas piramidales te idas con la t谷cnica de Golgi-Cox, de animales control (sin lesi車n) y animales con lesiones y sacrificados a distintos tiempos luego de la lesi車n. Se utilizaron cuatro grupos: sham (control), lesi車n 1S, lesi車n 3S y lesi車n 5S (animales con lesiones y evaluados 1, 3 y 5 semanas despu谷s de la lesi車n irreversible del nervio facial, respectivamente). Se evaluaron mediante el an芍lisis de Sholl, las ramificaciones dendr赤ticas de las c谷lulas piramidales de la corteza motora contralateral a la lesi車n. Resultados. Los animales con lesiones
%K rata
%K nervio facial
%K c谷lulas piramidales
%K corteza motora
%U http://www.revistabiomedica.org/index.php/biomedica/article/view/440