Glutamate, GABA and Serotonin concentrations in the cerebrospinal fluid and primary somatosensory cortex of birth-enucleated rats: Searching for S1 intrinsic and extrinsic epigenetic regulatory signals modulating neonatal cross-modal plasticity
- Published
- Accepted
- Subject Areas
- Developmental Biology, Neuroscience
- Keywords
- developmental timing, barrel expansion, S1 specification, thalamocortical afferents, neurotransmitters, blindness
- Copyright
- © 2016 Martínez-Méndez et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2016. Glutamate, GABA and Serotonin concentrations in the cerebrospinal fluid and primary somatosensory cortex of birth-enucleated rats: Searching for S1 intrinsic and extrinsic epigenetic regulatory signals modulating neonatal cross-modal plasticity. PeerJ PrePrints 4:e1782v1 https://doi.org/10.7287/peerj.preprints.1782v1
Abstract
Neonatal eye loss leads to an expansion of the primary somatosensory cortex (S1) in rodents. In blind rats, S1 expansion results from the predisplacement of S1 formation during the first three days of life, a process modulated by epigenetic factors. Some of these factors might be local and some others may come from extra-S1 sources such as the cerebrospinal fluid (CSF). Thus, we evaluated the concentration of glutamate, GABA and serotonin in the CSF and S1 of control and birth-enucleated rat pups. These neurotransmitters modulate through epigenetic mechanisms several aspects of brain development and also regulate S1 formation. Our results show, first, that axon segregation during barrel formation is discreetly predisplaced in birth-enucleated rats. Second, S1 glutamate, GABA and serotonin concentrations were similar in control and birth-enucleated rats during S1 formation. Lastly, CSF glutamate concentration decreased in birth-enucleated rats during S1 formation. Overall, our results open the possibility that neurochemical shifts in the CSF might modulate S1 expansion in enucleated rats. Further studies are needed to establish causal links.
Author Comment
First version, submitted as a preprint. We are currently working on determining the precise time for TCAs segregation in S1 tangential slices stained with the acetylcholinesterase (ChAT) histochemistry. We are also evaluating if there are differences in the S1 NMDA receptor subunit composition between CTRL and birth-enucleated pups through immunocytochemistry. Lastly, we are designing an experiment to pharmacologically manipulate the levels of glutamate in the CSF in birth-enucleated pups to evaluate the effect of such manipulation on barrel formation.
Supplemental Information
Figures 1 and 2. TCAs segregation and neurotransmitters concentration
The first sheet shows the number and percentage of individuals with segregated barrels at the 3 ages studied. The second sheet shows the concentration of the neurotransmitters in S1 and CSF as quantified by HPLC.