data Data Descriptor Data on the Quantification of Aspartate, GABA and Glutamine Levels in the Spinal Cord of Larval Sea Lampreys after a Complete Spinal Cord Injury Blanca Fernández-López 1 , Natividad Pereiro 2, Anunciación Lafuente 3,†, María Celina Rodicio 1 and Antón Barreiro-Iglesias 1,* 1 Department of Functional Biology, CIBUS, Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain; [email protected] (B.F.-L.); [email protected] (M.C.R.) 2 Ministry of Health, Paseo del Prado, 18, 28014 Madrid, Spain; [email protected] 3 Laboratory of Toxicology, Sciences School, University of Vigo, Las Lagunas s/n, 32004 Ourense, Spain * Correspondence: [email protected] † Deceased. Abstract: We used high-performance liquid chromatography (HPLC) methods to quantify aspartate, GABA, and glutamine levels in the spinal cord of larval sea lampreys following a complete spinal cord injury. Mature larval sea lampreys recover spontaneously from a complete spinal cord transection and the changes in neurotransmitter systems after spinal cord injury might be related to their amazing regenerative capabilities. The data presented here show the concentration of the aminoacidergic neurotransmitters GABA (and its precursor glutamine) and aspartate in the spinal cord of control (non-injured) and 2-, 4-, and 10-week post-lesion animals. Statistical analyses showed that GABA Citation: Fernández-López, B.; and aspartate levels significantly increase in the spinal cord four weeks after a complete spinal cord Pereiro, N.; Lafuente, A.; Rodicio, injury and that glutamine levels decrease 10 weeks after injury as compared to controls. These data M.C.; Barreiro-Iglesias, A. Data on the might be of interest to those studying the role of neurotransmitters and neuromodulators in recovery Quantification of Aspartate, GABA from spinal cord injury in vertebrates. and Glutamine Levels in the Spinal Cord of Larval Sea Lampreys after a Dataset: http://doi.org/10.5281/zenodo.4772417 Complete Spinal Cord Injury. Data 2021, 6, 54. https://doi.org/10.3390/ Dataset License: CC-BY-NC. data6060054 Keywords: aspartate; GABA; glutamine; HPLC; spinal cord injury; lampreys Academic Editor: Juraj Gregáˇn Received: 4 May 2021 Accepted: 23 May 2021 Published: 24 May 2021 1. Summary In contrast to humans, lampreys recover locomotion spontaneously several weeks Publisher’s Note: MDPI stays neutral after a complete spinal cord injury (SCI) [1]. We and others have shown that changes in the with regard to jurisdictional claims in functional and anatomical organization of neurotransmitter systems [2–11] and changes in published maps and institutional affil- neurotransmitter levels [12] after a complete SCI could be important contributors to the iations. recovery process in lampreys. Interestingly, recent work from our group has also shown that different neurotransmitters control the regeneration of descending axons and the survival of descending brainstem neurons after a complete SCI in lampreys (serotonin, [13]; GABA, [14–18]; taurine, [12]). In the course of a recent investigation of the role of taurine Copyright: © 2021 by the authors. during axonal regeneration after SCI in lampreys we used HPLC methods to measure Licensee MDPI, Basel, Switzerland. taurine levels in the spinal cord of control and injured animals [12]. We have now used the This article is an open access article same samples to measure changes in GABA (and its precursor glutamine) and aspartate distributed under the terms and levels. We recently showed that endogenous GABA promotes the survival and regenera- conditions of the Creative Commons tion of descending neurons of lampreys after a complete SCI by acting through GABAB Attribution (CC BY) license (https:// receptors expressed in those neurons [15]. However, changes in GABA (or its precursor creativecommons.org/licenses/by/ glutamine) levels in the spinal cord of lampreys after SCI have never been measured in 4.0/). Data 2021, 6, 54. https://doi.org/10.3390/data6060054 https://www.mdpi.com/journal/data Data 2021, 6, 54 2 of 4 However, changes in GABA (or its precursor glutamine) levels in the spinal cord of lampreys after SCI have never been measured in the past. Aspartate acts as an excitatory neurotransmitter in the central nervous system of vertebrates [19,20] and lampreys contain a complex aspartatergic system in the spinal cord [21]. However, changes in the organization of the aspartatergic system or in aspartate levels has not been analyzed yet after SCI in lampreys. Here, we provide a dataset with measurements of aspartate, GABA and glutamine levels in the spinal cord of control (non‐injured) and 2‐, 4‐, and 10‐week post‐lesion (wpl) larval sea lampreys. These data might be of interest to understand the events that lead to successful recovery from SCI in lampreys and for those studying the role of neurotransmitters and neuromodulators in neuronal regeneration and plasticity Data 2021, 6, 54 after SCI. These data can be compared with similar2 of 5 data on other neurotransmitter systems of lampreys and other vertebrates. the past. Aspartate acts as an excitatory neurotransmitter in the central nervous system of vertebrates [19,20] and lampreys contain a complex aspartatergic system in the spinal 2.cord Data [21]. However, Description changes in the organization of the aspartatergic system or in aspar- tate levels has not been analyzed yet after SCI in lampreys. Here, we provide a dataset with measurementsAspartate, of aspartate, GABA GABA and and glutamineglutamine levels in levels the spinal in cord the of control spinal cord of control (un‐lesioned) and (non-injured) and 2-, 4-, and 10-week post-lesion (wpl) larval sea lampreys. These data injuredmight be of interest(2, 4, to and understand 10 thewpl) events mature that lead to successfullarval recoverysea lampreys from SCI in are shown in the Supplementary Tablelampreys (available and for those studying also theat role http://doi.org/10.5281/zenodo.4772417, of neurotransmitters and neuromodulators in accessed on 20 May 2021) neuronal regeneration and plasticity after SCI. These data can be compared with similar anddata on in other Figure neurotransmitter 1. As systems explained of lampreys in and the other vertebrates.methods section, aspartate, GABA, and glutamine concentrations2. Data Description (ng/mg of protein) were measured in 5 samples for each experimental Aspartate, GABA and glutamine levels in the spinal cord of control (un-lesioned) and group.injured (2, 4,Each and 10 sample wpl) mature contained larval sea lampreys 7 spinal are shown cord in the Supplementary pieces (1 mm rostral and 1 mm caudal from theTable injury (available alsosite at http://doi.org/10.5281/zenodo.4772417at the level of the 5th gill), accessed from on 20 May7 different 2021) animals (140 animals in total). and in Figure1. As explained in the methods section, aspartate, GABA, and glutamine Statisticalconcentrations (ng/mganalyses of protein) revealed were measured a significant in 5 samples for each increase experimental in aspartate (One‐way ANOVA p = group. Each sample contained 7 spinal cord pieces (1 mm rostral and 1 mm caudal from 0.0007;the injury siteFigure at the level 1A) of theand 5th gill)GABA from 7 different(One‐ animalsway (140ANOVA animals in p total). = 0.0004; Figure 1B) levels in the spinal cordStatistical at analyses 4 wpl, revealed and a significant a significant increase in aspartate decrease (One-way in ANOVA glutaminep = 0.0007; levels at 10 wpl (One‐way ANOVA Figure1A ) and GABA (One-way ANOVA p = 0.0004; Figure1B) levels in the spinal cord pat = 4 0.0043; wpl, and a significantFigure decrease1C). in glutamine levels at 10 wpl (One-way ANOVA p = 0.0043; Figure1C). Figure 1. Cont. Figure 1. (A) Graph showing aspartate concentration in the spinal cord of control and injured animals (control: 0.001288 ± 0.0002611 ng aspartate/mg protein; 2 wpl: 0.002647 ± 0.0005217 ng Data 2021, 6, 54 2 of 4 However, changes in GABA (or its precursor glutamine) levels in the spinal cord of lampreys after SCI have never been measured in the past. Aspartate acts as an excitatory neurotransmitter in the central nervous system of vertebrates [19,20] and lampreys contain a complex aspartatergic system in the spinal cord [21]. However, changes in the organization of the aspartatergic system or in aspartate levels has not been analyzed yet after SCI in lampreys. Here, we provide a dataset with measurements of aspartate, GABA and glutamine levels in the spinal cord of control (non‐injured) and 2‐, 4‐, and 10‐week post‐lesion (wpl) larval sea lampreys. These data might be of interest to understand the events that lead to successful recovery from SCI in lampreys and for those studying the role of neurotransmitters and neuromodulators in neuronal regeneration and plasticity after SCI. These data can be compared with similar data on other neurotransmitter systems of lampreys and other vertebrates. 2. Data Description Aspartate, GABA and glutamine levels in the spinal cord of control (un‐lesioned) and injured (2, 4, and 10 wpl) mature larval sea lampreys are shown in the Supplementary Table (available also at http://doi.org/10.5281/zenodo.4772417, accessed on 20 May 2021) and in Figure 1. As explained in the methods section, aspartate, GABA, and glutamine concentrations (ng/mg of protein) were measured in 5 samples for each experimental group. Each sample contained 7 spinal cord pieces (1 mm rostral and 1 mm caudal from the injury site at the level of the 5th gill) from 7 different animals (140 animals in total). Statistical analyses revealed a significant increase in aspartate (One‐way ANOVA p = 0.0007; Figure 1A) and GABA (One‐way ANOVA p = 0.0004; Figure 1B) levels in the spinal cord at 4 wpl, and a significant decrease in glutamine levels at 10 wpl (One‐way ANOVA p = 0.0043; Figure 1C). Data 2021, 6, 54 3 of 5 Figure 1.