Ghrelin induced transcription of Bdnf promoters in hippocampal slices

PEREA VEGA MARY LUZ; MARTÍN MAURICIO; RUBIALES SUSANA DE BARIOGLIO

Córdoba

Jornada; II Jornadas de investigacion cientifica; 2017

Instituto de Investigación Médica Mercedes y Martín Ferreyra

Ghrelin (Gr) is a peptide which participates in the modulation of various biological processes. In previous work, we have shown that the administration in rats Gr either intracerebroventricularly or directly in brain areas such as the hippocampus (Hp), improves memory retention in a dose dependent on the different behavioral paradigms; Gr in the Hp also increases the excitability facilitating the induction of long-term potentiation (LTP), glutamate release and increases expression of NR2B subunit N-methyl-D-aspartate (NMDA) receptor. Activity regulated gene transcription is involved in multiple biological processes, in neuronal survival and in the late phases of LTP processes underlying memory formation.One of the most extensively studied genes that are regulated by neuronal activity is the brain derived neurotrophic factor (BDNF) which plays important roles in synaptic plasticity. Hippocampal neurons are known to be a site of important CNS expression of BDNF in adulthood. Moreover, the increased expression of BDNF has been associated with induction and evoking stimuli LTP in neurons HpCalcium entry through L-type VSCCs channels or activation of the NMDA subtype of glutamate receptors stimulates transcription of BDNF which leads to improved levels of BDNF mRNA and stimulate the release of the neurotrophin which modulates synaptic activity. The purpose of this paper is to add new knowledge about the mechanisms by which modulates Gr memory processes.Taking in mind the previously demonstrated effects of Gr and BDNF we examined if Gr could increase BDNF promoters expression and contribute to the increase in synaptic efficacy induced by the peptide in Hp. Hippocampal slices were exposed to Gr (nM) 15 min and the expression levels of exons I, II, IV and VI were determined by PCR (RT.-PCR) at different time points the results show that Gr stimulation. Induces a significant increase in the transcripts II and VI. The amount of these mRNAs peaked at 30 min after stimulation .These preliminary results suggest that BDNF could contribute to increased synaptic plasticity induced by the peptide.