VEGF is an essential retrograde trophic factor for motoneurons

VEGF was initially discovered due to its angiogenic activity and therefore named "vascular endothelial growth factor."However, its more recently discovered neurotrophic activity may be evolutionarily more ancient. Our previous work showed that all the changes produced by axotomy on the fir...

Descripción completa

Detalles Bibliográficos
Autores: Martín Calvo, Paula, García Hernández, Rosendo Miguel, Rodríguez de la Cruz, Rosa María, Pastor Loro, Ángel Manuel
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2022
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/151685
Acceso en línea:https://hdl.handle.net/11441/151685
https://doi.org/10.1073/pnas.2202912119
Access Level:acceso abierto
Palabra clave:Abducens
Axotomy
Neurotrophic factors
Oculomotor
Synaptic stripping
Descripción
Sumario:VEGF was initially discovered due to its angiogenic activity and therefore named "vascular endothelial growth factor."However, its more recently discovered neurotrophic activity may be evolutionarily more ancient. Our previous work showed that all the changes produced by axotomy on the firing activity and synaptic inputs of abducens motoneurons were completely restored after VEGF administration. Therefore, we hypothesized that the lack of VEGF delivered by retrograde transport from the periphery should also affect the physiology of otherwise intact abducens motoneurons. For VEGF retrograde blockade, we chronically applied a neutralizing VEGF antibody to the lateral rectus muscle. Recordings of extracellular single-unit activity and eye movements were made in alert cats before and after the application of the neutralizing antibody. Our data revealed that intact, noninjured abducens motoneurons retrogradely deprived of VEGF exhibited noticeable changes in their firing pattern. There is a general decrease in firing rate and a significant reduction in eye position and eye velocity sensitivity (i.e., a decrease in the tonic and phasic components of their discharge, respectively). Moreover, by means of confocal immunocytochemistry, motoneurons under VEGF blockade showed a marked reduction in the density of afferent synaptic terminals contacting with their cell bodies. Altogether, the present findings demonstrate that the lack of retrogradely delivered VEGF renders abducens motoneurons into an axotomy-like state. This indicates that VEGF is an essential retrograde factor for motoneuronal synaptic drive and discharge activity.