Aging is associated with a modality-specific decline in taste
Elizabeth B Brown1,2, Evan Lloyd1,2, Rose Riley1
1Department of Biological Sciences, Florida State University, Tallahassee, FL 32306, USA.
Iscience
|October 9, 2024
Summary
Aging impairs taste in fruit flies, affecting sugar but not fatty acid detection. This taste deficit is mimicked by amyloid beta expression, suggesting distinct aging and Alzheimer
Area of Science:
- Neuroscience
- Aging Research
- Chemosensation
Background:
- Chemosensory processing declines with age and in neurodegenerative diseases like Alzheimer's disease (AD).
- The fruit fly, Drosophila melanogaster, serves as a model organism for studying aging and neurodegeneration, but its taste function during these processes is understudied.
Purpose of the Study:
- To investigate the impact of aging and neurodegeneration on taste function in Drosophila.
- To explore the specific mechanisms underlying age-related and AD-related taste deficits.
Main Methods:
- Behavioral assays to assess responses to sugars and fatty acids in aged and genetically modified flies.
- Functional imaging of gustatory axon terminals.
- Analysis of gene expression in taste neurons.
Main Results:
- Aging reduced responses to sugars but not medium-chain fatty acids.
- Expression of human amyloid beta (Aβ) mimicked aging-related taste deficits.
- Functional imaging showed reduced sugar responses in axon terminals, with Aβ impacting axonal innervation.
- 66 age-related gene expression changes were identified in sugar-sensing neurons.
Conclusions:
- Taste deficits in aged and AD model flies involve distinct mechanisms.
- Aging primarily affects sugar perception, while amyloid beta impacts neuronal structure and function.
- Drosophila is a valuable model for dissecting age- and disease-related chemosensory impairments.
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