title: Rapid upregulation of the hippocampal connexins 36 and 45 mRNA levels during memory consolidation.
abstract: Gap junction channels are implicated in learning and memory process. However, their role on each of the particular stages of memory formation has been studied less. In this study, the time profile of the expression levels of hippocampal connexins 36 and 45 (Cx36 and Cx45) mRNAs was measured during memory consolidation, in a passive avoidance paradigm. Totally 30 adult male rats were distributed into 5 groups of each 6. At different times profiles (30min, 3, 6 and 24h) following training, rats were decapitated and their hippocampi were immediately removed and frozen in liquid nitrogen. Total RNA was extracted and cDNA was synthesized, using oligo-dtprimers. A quantitative real-time PCR was used to measure the levels of each of Cx36 and Cx45 mRNAs. Both connexins showed a rapid upregulation (30min) at the transcriptional level, which declined in later times and reached to the control level at 24h. The rapid up-regulation of Cx36 and Cx45 mRNAs might be accompanied with increasing intercellular coupling via gap junction channels and neuronal oscillatory activities required for memory consolidation. The results highlight the role of gap junctional coupling between hippocampal neurons during memory consolidation in the physiological conditions.
authors.affiliation: Division of Animal Sciences, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran. Electronic address: siamak.beheshti@yahoo.com.
authors.forename: Siamak
authors.initials: S
authors.lastname: Beheshti
authors.affiliation: Division of Animal Sciences, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran.
authors.forename: Reyhaneh
authors.initials: R
authors.lastname: Zeinali
authors.affiliation: Division of Cellular and Molecular Biology, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran.
authors.forename: Abolghasem
authors.initials: A
authors.lastname: Esmaeili
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D017630:Connexins / Q000235:genetics* / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D000069077:Memory Consolidation / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D015854:Up-Regulation / Q000502:physiology*; D000097004:Gap Junction delta-2 Protein
chemical_list: D017630:Connexins; D012333:RNA, Messenger; D000097004:Gap Junction delta-2 Protein; C082920:connexin 45
keywords: Connexin; Gap junctions; Hippocampus; Memory consolidation; Passive avoidance task