Regulation of the spatial code for BDNF mRNA isoforms in the rat hippocampus following pilocarpine-treatment: A systematic analysis using laser microdissection and quantitative real-time PCR
Article first published online: 25 FEB 2013
Copyright © 2013 Wiley Periodicals, Inc.
Volume 23, Issue 5, pages 413–423, May 2013
How to Cite
Baj, G., Del Turco, D., Schlaudraff, J., Torelli, L., Deller, T. and Tongiorgi, E. (2013), Regulation of the spatial code for BDNF mRNA isoforms in the rat hippocampus following pilocarpine-treatment: A systematic analysis using laser microdissection and quantitative real-time PCR. Hippocampus, 23: 413–423. doi: 10.1002/hipo.22100
- Issue published online: 8 APR 2013
- Article first published online: 25 FEB 2013
- Manuscript Accepted: 8 JAN 2013
- Italy-Germany cooperation grant, “Vigoni Project”
- mRNA trafficking;
- untranslated regions;
- pilocarpine seizures;
- neurotrophic factors;
- neuronal dendrites
Brain-derived neurotrophic factor (BDNF) is essential for neuronal survival, differentiation, and plasticity and is one of those genes that generate multiple mRNAs with different alternatively spliced 5′UTRs. The functional significance of many BDNF transcripts, each producing the same protein, is emerging. On the basis of the analysis of the four most abundant brain BDNF transcripts, we recently proposed the “spatial code hypothesis of BDNF splice variants” according to which the BDNF transcripts, through their differential subcellular localization in soma or dendrites, represent a mechanism to synthesize the protein at distinct locations and produce local effects. In this study, using laser microdissection of hippocampal laminae and reverse transcription-quantitative real-time PCR (RT-qPCR), we analyzed all known BDNF mRNA variants at resting conditions or following 3 h pilocarpine-induced status epilepticus. In untreated rats, we found dendritic enrichment of BDNF transcripts encoding exons 6 and 7 in CA1; exons 1, 6, and 9a in CA3; and exons 5, 6, 7, and 8 in DG. Considering the low abundance of the other transcripts, exon 6 was the main transcript in dendrites under resting conditions. Pilocarpine treatment induced an increase of BDNF transcripts encoding exons 4 and 6 in all dendritic laminae and, additionally, of exon 2 in CA1 stratum radiatum and exons 2, 3, 9a in DG molecular layer while the other transcripts were decreased in dendrites, suggesting restriction to the soma. These results support the hypothesis of a spatial code to differentially regulate BDNF in the somatic or dendritic compartment under conditions of pilocarpine-induced status epilepticus and, furthermore, highlight the existence of subfield-specific differences. © 2013 Wiley Periodicals, Inc.