Reference : Plasma glucocorticoids differentially modulate phasic and tonic GABA inhibition durin...
Scientific journals : Article
Life sciences : Anatomy (cytology, histology, embryology...) & physiology
http://hdl.handle.net/10993/19138
Plasma glucocorticoids differentially modulate phasic and tonic GABA inhibition during early postnatal development in rat spinal lamina II.
English
Zell, Vivien [> >]
Hanesch, Ulrike mailto [University of Luxembourg > Faculty of Language and Literature, Humanities, Arts and Education (FLSHASE) > Integrative Research Unit: Social and Individual Development (INSIDE) > Institute for Health and Behaviour]
Poisbeau, Pierrick [> >]
Anton, Fernand mailto [University of Luxembourg > Faculty of Language and Literature, Humanities, Arts and Education (FLSHASE) > Integrative Research Unit: Social and Individual Development (INSIDE) > Institute for Health and Behaviour]
Darbon, Pascal [> >]
2014
Neuroscience letters
578
39-43
Yes (verified by ORBilu)
0304-3940
1872-7972
Ireland
[en] GABA extrasynaptic transmission ; GABA synaptic transmission ; Glucocorticoids ; Mechanical pain sensitivity ; Spinal dorsal horn
[en] Nociceptive processing is tuned by GABAA receptor-mediated inhibition in the spinal cord dorsal horn that undergoes postnatal maturation in rodents. These GABAergic inhibitory postsynaptic currents (IPSCs) are modulated by 3alpha5alpha-reduced steroids during early postnatal development in spinal cord lamina II. Thus an enhanced phasic inhibition is present in neonates and decreases over time. GABA can also activate extrasynaptic receptors, giving rise to tonic inhibition. In this study, we characterized the contribution of plasma corticosterone (CORT) to postnatal maturation of spinal phasic and, for the first time, tonic GABAergic inhibitions. We used Fisher and Lewis rat strains displaying respectively high and low hypothalamic-pituitary-adrenal axis reactivity, compared to control Sprague-Dawley rats. Measured plasma CORT levels were significantly higher in Fisher rats, which also displayed significantly higher mechanical nociceptive thresholds, supporting the hypothesis of an antinociceptive action of CORT. Recorded GABAA IPSCs shortened during maturation in all strains while remaining larger in Fisher rats. Blocking the 5alpha-reduction of steroids in Fisher rats produced a further decrease of IPSC deactivation time constant. In contrast, GABAA tonic inhibition progressively increased during maturation, without any difference among strains. In conclusion, we show that both phasic and tonic GABAergic inhibitions undergo postnatal maturation in lamina II. Moreover spinal production of 3alpha5alpha-reduced steroids that presumably derive from plasma CORT is correlated to spinal GABAA phasic (but not tonic) inhibition and to mechanical nociceptive thresholds.
F3R-INS-PUL-11STPA
http://hdl.handle.net/10993/19138
Copyright (c) 2014 Elsevier Ireland Ltd. All rights reserved.

File(s) associated to this reference

Fulltext file(s):

FileCommentaryVersionSizeAccess
Limited access
Zell-et-al2014_GABA inhibition.pdfPublisher postprint474.31 kBRequest a copy

Bookmark and Share SFX Query

All documents in ORBilu are protected by a user license.