title: Impaired sense of smell in a Drosophila Parkinson's model.
abstract: Parkinson's disease (PD) is one of the most common neurodegenerative disease characterized by the clinical triad: tremor, akinesia and rigidity. Several studies have suggested that PD patients show disturbances in olfaction at the earliest onset of the disease. The fruit fly Drosophila melanogaster is becoming a powerful model organism to study neurodegenerative diseases. We sought to use this system to explore olfactory dysfunction, if any, in PINK1 mutants, which is a model for PD. PINK1 mutants display many important diagnostic symptoms of the disease such as akinetic motor behavior. In the present study, we describe for the first time, to the best of our knowledge, neurophysiological and neuroanatomical results concerning the olfactory function in PINK1 mutant flies. Electroantennograms were recorded in response to synthetic and natural volatiles (essential oils) from groups of PINK1 mutant adults at three different time points in their life cycle: one from 3-5 day-old flies, from 15-20 and from 27-30 days. The results obtained were compared with the same age-groups of wild type flies. We found that mutant adults showed a decrease in the olfactory response to 1-hexanol, α-pinene and essential oil volatiles. This olfactory response in mutant adults decreased even more as the flies aged. Immunohistological analysis of the antennal lobes in these mutants revealed structural abnormalities, especially in the expression of Bruchpilot protein, a marker for synaptic active zones. The combination of electrophysiological and morphological results suggests that the altered synaptic organization may be due to a neurodegenerative process. Our results indicate that this model can be used as a tool for understanding PD pathogensis and pathophysiology. These results help to explore the potential of using olfaction as a means of monitoring PD progression and developing new treatments.
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Poddighe
authors.forename: Krishna Moorthi
authors.initials: KM
authors.lastname: Bhat
authors.forename: Maria Dolores
authors.initials: MD
authors.lastname: Setzu
authors.forename: Paolo
authors.initials: P
authors.lastname: Solla
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Angioy
authors.forename: Roberto
authors.initials: R
authors.lastname: Marotta
authors.forename: Roberta
authors.initials: R
authors.lastname: Ruffilli
authors.forename: Francesco
authors.initials: F
authors.lastname: Marrosu
authors.forename: Anna
authors.initials: A
authors.lastname: Liscia
mesh_terms: D000818:Animals; D057506:Arthropod Antennae / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D001522:Behavior, Animal; D004195:Disease Models, Animal; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster; D005071:Evoked Potentials; D005786:Gene Expression Regulation; D008136:Longevity / Q000235:genetics; D008297:Male; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D009154:Mutation; D009830:Olfactory Bulb / Q000503:physiopathology; D055696:Olfactory Perception; D010300:Parkinson Disease / Q000235:genetics / Q000503:physiopathology*; D017729:Presynaptic Terminals / Q000648:ultrastructure; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D012903:Smell; D000099202:PTEN-Induced Putative Kinase
chemical_list: D029721:Drosophila Proteins; D017346:Protein Serine-Threonine Kinases; C510146:BRP protein, Drosophila; C534484:PINK1 protein, Drosophila; D000099202:PTEN-Induced Putative Kinase