Regulation of Neuroligins and Neuroxin 1 in the adult honeybee brain according to early olfactory experiences

BARNETO JA,; ZAVALA JA; GROSSO JP; PAGANO EA; VELARDE RA; FARINA WM

Montevideo

Congreso; XII International Congress of Neuroethology; 2016

International Society of Neuroethology

Neurexins and neuroligins are highly conserved adhesive proteins found on synaptic membranes. These proteins produce a trans-synaptic bridge that facilitates maturation and specification of synapses. In the Drosophila larvae, Neurexin 1 is required for synapse formation and associative learning; while in the honeybee, increased levels of Neurexins and Neuroligins have been reported in the adult brain after olfactory learning. Since the interaction between these proteins guides synapse formation, we investigated whether these connected proteins are differentially regulated in the mature adult honeybee brain according to early time, specific odor-rewarded inputs. We evaluated gene expression levels of these synaptic anchors proteins in bees of 17 days of age that had undergone associative odor training at different periods of early adulthood. Bees had been fed with scented food (sucrose solution scented with 1-Hexanol) only during the period of either 1-4 or 5-8 or 9-12 days of age and compared with a control group (always odorless food; n=9, pools of 10 brains each). At 17 days of age, bees were anesthetized and their brains dissected and put in liquid nitrogen. Then TRIZOL extraction of mRNA was performed and qRT-PCR was performed to assess expression levels of Nlg2-5 and Nrx1. Results show that events of associative learning occurred during 5-8 days of age can boost the expression levels of Nrx1 and Nlg2. Therefore, early olfactory experiences improved their synapse formation.