Blanca Fernández-López and Silvia María Valle-Maroto contributed equally to this work.
Neuronal release and successful astrocyte uptake of aminoacidergic neurotransmitters after spinal cord injury in lampreys
Article first published online: 15 APR 2014
© 2014 Wiley Periodicals, Inc.
Volume 62, Issue 8, pages 1254–1269, August 2014
How to Cite
Fernández-López, B., Valle-Maroto, S. M., Barreiro-Iglesias, A. and Rodicio, M. C. (2014), Neuronal release and successful astrocyte uptake of aminoacidergic neurotransmitters after spinal cord injury in lampreys. Glia, 62: 1254–1269. doi: 10.1002/glia.22678
- Issue published online: 14 JUN 2014
- Article first published online: 15 APR 2014
- Manuscript Accepted: 3 APR 2014
- Manuscript Revised: 13 MAR 2014
- Spanish Ministry of Science and Innovation. Grant Number: BFU2010–17174
- postdoctoral fellowship from the Xunta de Galicia
- spinal cord injury;
In contrast to mammals, the spinal cord of lampreys spontaneously recovers from a complete spinal cord injury (SCI). Understanding the differences between lampreys and mammals in their response to SCI could provide valuable information to propose new therapies. Unique properties of the astrocytes of lampreys probably contribute to the success of spinal cord regeneration. The main aim of our study was to investigate, in the sea lamprey, the release of aminoacidergic neurotransmitters and the subsequent astrocyte uptake of these neurotransmitters during the first week following a complete SCI by detecting glutamate, GABA, glycine, Hu and cytokeratin immunoreactivities. This is the first time that aminoacidergic neurotransmitter release from neurons and the subsequent astrocytic response after SCI are analysed by immunocytochemistry in any vertebrate. Spinal injury caused the immediate loss of glutamate, GABA and glycine immunoreactivities in neurons close to the lesion site (except for the cerebrospinal fluid-contacting GABA cells). Only after SCI, astrocytes showed glutamate, GABA and glycine immunoreactivity. Treatment with an inhibitor of glutamate transporters (DL-TBOA) showed that neuronal glutamate was actively transported into astrocytes after SCI. Moreover, after SCI, a massive accumulation of inhibitory neurotransmitters around some reticulospinal axons was observed. Presence of GABA accumulation significantly correlated with a higher survival ability of these neurons. Our data show that, in contrast to mammals, astrocytes of lampreys have a high capacity to actively uptake glutamate after SCI. GABA may play a protective role that could explain the higher regenerative and survival ability of specific descending neurons of lampreys. GLIA 2014;62:1254–1269