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

GROSSO JUAN P.; BARNETO JESICA A.; ZAVALA JORGE A.; FARINA WALTER M

Montevideo

Congreso; XII International Congress of Neuroethology; 2016

International Society for Neuroethology

Neurexins and neuroligins are highly conservedadhesive proteins found on synaptic membranes. These proteins produce a trans-synapticbridge that facilitates maturation and specification of synapses. In the Drosophila larvae, Neurexin 1 is requiredfor synapse formation and associative learning; while in the honeybee, increasedlevels of Neurexins and Neuroligins has been reported in the adultbrain after olfactory learning. Since the interaction between these proteins guidessynapse formation, we investigated whether these connected proteins aredifferentially regulated in the mature adult honeybee brain according to early time-specificodor-rewarded inputs.We evaluatedgene expression levels of these synaptic anchors proteins in bees of 17 days ofage that had undergone associative odor training at different periods of theearly adulthood. Bees had been fed with scented food (sucrose solution scentedwith 1-Hexanol) only during the period of either 1-4 or 5-8 or 9-12 days of ageand compared with a control group (always odorless food; n=9, pools of 10brains each). At 17 days of age, bees were anesthetized and their brainsdissected and put in liquid nitrogen. Then TRIZOL extraction of mRNA wasperformed and qRT-PCR was performed to assess expression levels of Nlg2-5 and Nrx1.Results show thatevents of associative learning occurred during 5-8 days of age can boost the expressionlevels of Nrx1 and Nlg2. Therefore, early olfactory experiences promote notonly the already reported functional and structural changes in the mature honeybeebrain, but also improved their synapse formation.