Transcript expression of vesicular glutamate transporters in lumbar dorsal root ganglia and the spinal cord of mice - Effects of peripheral axotomy or hindpaw inflammation

MALET, M; VIEYTES, C; LUNDGREN, KH; SEAL, RP; TOMASELLA, E; SEROOGY, KB; HOKFELT, T; GEBHART, GF; BRUMOVSKY, PR

NEUROSCIENCE

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2013 vol. 248 p. 95 - 111

0306-4522

Using specific riboprobes, we characterized the expression of VGLUT1-VGLUT3 transcripts in lumbar 4-5 (L4-5) DRGs and the thoracolumbar to lumbosacral spinal cord in male BALB/C mice after a 1 or 3-day hindpaw inflammation, or a 7-day sciatic nerve axotomy. Sham animals were also included. In sham and contralateral L4-5 DRGs of injured mice, VGLUT1-, VGLUT2- and VGLUT3 mRNAs were expressed in ~45%, ~69% or ~17% of all neuron profiles (NPs), respectively. VGLUT1 was expressed in large and some medium-sized NPs; VGLUT2 in neurons of all sizes, and VGLUT3 in small and medium-sized NPs. In the spinal cord, VGLUT1 was restricted to a number of neurons at thoracolumbar and lumbar levels, in what appears to be the dorsal nucleus of Clarke, and in mid laminae III-IV. In contrast, VGLUT2 was present in numerous NPs at all analyzed spinal levels, except the lateral aspects of the ventral horns, especially at the lumbar enlargement, were it was virtually absent. VGLUT3 was detected in a discrete number of neurons in laminae III-IV of the dorsal horn. Axotomy resulted in a moderate decrease in the number of DRG NPs expressing VGLUT3; VGLUT1 and VGLUT2 were unaffected. Likewise, VGLUTs transcripts remained unaltered after hindpaw inflammation, both in DRGs and the spinal cord. Altogether, these results confirm previous descriptions on VGLUTs, with the exception of VGLUT1, whose protein expression was detected in a lesser percentage of mouse DRG NPs. We also show a modest decrease in VGLUT3 transcript in DRGs. Lack of changes after injury for VGLUT1 and VGLUT2 transcripts (and VGLUT3 after hindpaw inflammation), as compared to data on protein expression, suggests translational/trafficking over transcriptional regulations of VGLUTs after injury.