RESUMEN
Two groups of Sprague-Dawley male rats received bilateral aspirative lesions of the fimbria fornix under chloral hydrate anesthesia. One group (n = 9) received no further treatment (lesioned). In the second group (n = 8), a piece of septal fetal tissue, obtained at day E15-16, was implanted into each lesion cavity (transplanted). A third group consisted of shamlesioned rats (controls, n = 14). Two months after the operations, a recording electrode was implanted in the hilar region of the dentate gyrus of each animal, and a bipolar stimulating electrode was implanted in the perforant path. Long-term potentiation at 400 Hz was induced and followed for two hours. FF-lesioned rats showed an impaired potentiation of the field excitatory post-synaptic potential, which rapidly declined to basal levels within 15 minutes. The transplanted rats showed a normal potentiation of this parameter, similar to that seen in the control animals. A decrease in choline acetyltransferase activity in the hippocampi of the lesioned animals showed a tendency toward recovery after septal fetal tissue transplantation. In all the dorsal hippocampal areas of the lesioned animals, acetylcholinesterase histochemistry showed an almost complete loss of enzymatic activity, which was partially restored by the transplants. The improved synaptic plasticity in the transplanted animals might be related to septal transplant-induced recovery of mnemonic functions.
Asunto(s)
Trasplante de Tejido Encefálico/fisiología , Giro Dentado/fisiología , Trasplante de Tejido Fetal/fisiología , Hipocampo/fisiología , Potenciación a Largo Plazo/fisiología , Acetilcolinesterasa/metabolismo , Animales , Colina O-Acetiltransferasa/metabolismo , Giro Dentado/enzimología , Estimulación Eléctrica , Electrofisiología , Potenciales Evocados/fisiología , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
We have previously shown that hypothalamic fetal brain grafts induced recovery of sexual behavior in medial preoptic area (MPOA)-lesioned male rats. In the present series of experiments, male rats with completely abolished sexual behavior by MPOA lesions received either hypothalamic or frontal cortical fetal grafts. The animals that received hypothalamic grafts showed a gradual recovery of sexual behavior. In contrast, those animals who received cortical grafts did not recover sexual behavior during the 15 weeks after the graft. In addition, to evaluate the connectivity of the grafted tissue with the host brain, a retrograde tracer, fluorogold, was injected in the dorsal tegmental area. Fluorogold-labeled cells were found in the hypothalamic, but not in the cortical grafts. These results suggest that specificity of the grafted tissue and connectivity between brain grafts and host tissue are necessary for the recovery of male sexual behavior in MPOA-lesioned rats.
Asunto(s)
Trasplante de Tejido Encefálico/fisiología , Corteza Cerebral/trasplante , Hipotálamo/trasplante , Área Preóptica/fisiología , Conducta Sexual Animal/fisiología , Animales , Corteza Cerebral/fisiología , Estradiol/farmacología , Femenino , Trasplante de Tejido Fetal/fisiología , Hipotálamo/fisiología , Masculino , Especificidad de Órganos , Progesterona/farmacología , Ratas , Ratas Wistar , Conducta Sexual Animal/efectos de los fármacosRESUMEN
El uso de injertos cerebrales, útiles para restaurar la función en modelos animales de efermedad de Huntington (EH), se aplicó en una mujer de 37 años de edad con EH moderada a grave, de nueve años de evolución. Se trasplantaron los dos estriados de un feto humano de 13 semanas de edad gestacional en cuatro cavidades hechas en la pared ventricular del núcleo caudado derecho. Diez meses después de la cirugía, las evaluaciones neurológicas y neuropsicológica de la paciente revelaron la estabilización de su sintomatología y de la mayor parte de sus indicadores neuropsicológicos. Hubo mejoría moderada de los movimientos coréicos, principalmente los de la cara; de la capacidad para definir y expresar ideas en forma oral y escrita; de su agilidad articulatoria, así como en sus actividades cotidianas y en su comportamiento social. Ocurrió deterioro leve de la postura y la marcha; además se deterioraron su sistema sacádico y nistagmo optocinético, así como sus funciones visoespaciales y visoperceptuales