Effects on Learning and Memory of a Mutation in Dα7: A D. melanogaster Homolog of Alzheimer's Related Gene for nAChR α7
(1) Homestead High School, Cupertino, California, (2) Schmahl Science Workshop, San Jose, California
The nicotinic acetylcholine receptor α7 (nAChR α7) is a ligand-gated channel that releases neurotransmitters in excitatory neurons. Alzheimer's disease (AD) involves the reduction of cholinergic activity due to a decrease in neuronal levels of nAChR α7. This significant reduction makes nAChR α7 an intriguing target to study in the context of AD, specifically with regards to learning, memory, and locomotion, which are key affected abilities of the disease. Dα7 is the Drosophila melanogaster homolog of the nAChR, subunit α7. In this work, we explore the role of the nAChR α7 in learning and memory retention, using Drosophila melanogaster as a model organism. The performance of silenced Dα7-allele flies (PΔEY6) was analyzed in locomotive and olfactory-memory retention tests in comparison to wild type (WT) flies and an Alzheimer's disease model Arc-42 (Aβ-42). WT flies performed with average success rates of 80% in both the climbing assay and olfactory shock learning tests. In contrast, for the climbing assay, PΔEY6 flies performed with average success rates of 61% and the Aβ-42 flies performed with an average success rate of 60%. For the olfactory shock learning, the PΔEY6 flies performed with an average success rate of 45% and the Aβ-42 flies showed an average success rate of 43%. These results suggest that the lack of the D. melanogaster-nAChR causes learning, memory, and locomotion impairments, similar to those observed in Alzheimer's models Arc-42.