Cerebellar grafting in the oculomotor system as a model to study target influence on adult neurons.
In the last decades, there have been many efforts directed to gain a better understanding on adult neuron-target cell relationships. Embryonic grafts have been used for the study of neural circuit rewiring. Thus, using several donor neuronal tissues, such as cerebellum or striatum, developing grafted cells have been shown to have the capability of substituting neural cell populations and establishing reciprocal connections with the host. In addition, different lesion paradigms have also led to a better understanding of target dependence in neuronal cells. Thus, for example, axotomy induces profound morphofunctional changes in adult neurons, including the loss of synaptic inputs and discharge alterations. These alterations are probably due to trophic factor loss in response to target disconnection. In this review, we summarize the different strategies performed to disconnect neurons from their targets, and the effects of target substitution, performed by tissue grafting, upon neural properties. Using the oculomotor system-and more precisely the abducens internuclear neurons-as a model, we describe herein the effects of disconnecting a population of central neurons from its natural target (i.e., the medial rectus motoneurons at the mesencephalic oculomotor nucleus). We also analyze target-derived influences in the structure and physiology of these neurons by using cerebellar embryonic grafts as a new target for the axotomized abducens internuclear neurons.
Benítez-Temiño
Beatriz
B
Dept. Fisiología y Zoología, Facultad de Biología, Universidad de Sevilla, Av. Reina Mercedes, 6 41012 Sevilla, E-41012, Spain.
de la Cruz
Rosa R
RR
Tena
Juan J
JJ
Pastor
Angel M
AM
D000010:Abducens Nerve / Q000503:physiopathology / Q000601:surgery; D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology; D019771:Axotomy; D016380:Brain Tissue Transplantation; D002531:Cerebellum / Q000166:cytology / Q000196:embryology / Q000637:transplantation* / Q000648:ultrastructure; D006133:Growth Substances / Q000494:pharmacology; D008954:Models, Biological; D009046:Motor Neurons / Q000502:physiology*; D009801:Oculomotor Muscles / Q000294:innervation* / Q000503:physiopathology; D014726:Vestibular Nuclei / Q000166:cytology / Q000503:physiopathology* / Q000601:surgery
D006133:Growth Substances