The Onset Of Sodium Appetite: Role Of Oxitocinergic And Serotonergic Central Systems.

CAEIRO X.; VIVAS L.; C. PORCARI; ANTUNES-RODRIGUES J; MECAWI A; GODINO A.

Congreso; Congreso Nacional de la sociedad Argentina de Neurosciencia, SAN 2018; 2018

THE ONSET OF SODIUM APPETITE: ROLE OF OXITOCINERGIC AND SEROTONERGIC CENTRAL SYSTEMS Porcari, C.1; Mecawi, A.2; Reis L.,Antunes-Rodrigues, J.2; Vivas, L.1; Godino, A.11.INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina; 2.Fac. Medicina de Ribeirao Preto, USP, Brazil.A temporal dissociation exists between sodium depletion (SD) and the appearance of sodium appetite behavior (SA), and an inhibitory modulation can be postulated. Previous studies demonstrated the inhibitory participation of serotonergic (5-HT) and oxytocinergic (OT) neurons on SA induced by SD (Godino et al., 2007). We recently found the serotonin 2C receptor (5HT2C) involved in the appearance of SA modulation (Porcari et al., 2017). Our aim was to evaluate during the delay of SA appearance after SD, gene expression changes of different components of central oxytocinergic (OT) and serotonergic (5HT) systems previously involved in SA regulation.Wistar rats were sodium depleted using furosemide combined with low sodium diet, and then at 2h or 24h later the animals were decapitated. Specific brain areas: dorsal raphe nucleus (DRN), subfornical organ (SFO), lateral parabrachial (LPBN) and anteroventral area of third ventricule (includes the organum vasculosum of the lamina terminalis and the ventral part of median preoptic nucleus) plus supraoptic nucleus (AV3V + SON), were submitted to RT-PCR of oxytocin receptor (OTR), serotonin 2A receptor (5HT2A), tryptophan hydroxylase 2 (TPH2) and serotonin transporter (SERT). OTR mRNA expression significantly increases (p=0.045) early at 2 hs after SD along AV3V + SON in comparison to control and 24 h SD groups. Besides, the opposite pat-tern was observed in the OTR mRNA expression along the DRN, decreasing 24 h after SD in relation to control and 2h SD groups, but this differences did not reach significant levels (p=0.06). On the other hand non-significant changes in the SERT and TPH2 mRNA expression along the DRN or the 5HT2A mRNA expression in the LPBN and SFO were observed.In sum, our results suggest that oxitocinergic circuit acting thought its receptors along nuclei previously involved in the regulation of sodium appetite (areas involved in the genesis and the inhibition of SA) may modulate SA appearance. Support by: CNPq, CONICET, Mincyt-Cba., Foncyt, SECyT.