Regional serotonin terminal density in aging human brain: A [¹¹C]DASB PET study

Area of Science:

• Neuroscience
• Radiochemistry
• Gerontology

Background:

• Conflicting findings exist regarding age-related changes in human brain serotonin terminal density.
• Some studies suggest declines, while others indicate stability across the adult lifespan.

Purpose of the Study:

• To investigate age-related changes in regional serotonin transporter density in the human brain.
• To resolve discrepancies in previous research on serotoninergic system aging.

Main Methods:

• Utilized [11C]3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile positron emission tomography (PET) in 46 healthy adults (25-84 years).
• Employed both voxel-based and volume-of-interest analyses, controlling for sex.
• Quantified brain regional serotonin transporter (SERT) density.

Main Results:

• Demonstrated significant age-related declines in [11C]3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile binding across multiple brain regions.
• Observed decreases in SERT density in neocortical areas, striatum, amygdala, thalamus, dorsal raphe, and other subcortical regions.
• Findings indicate a widespread reduction in serotonin terminal density with aging.

Conclusions:

• This study provides evidence for age-related declines in regional serotonin terminal density in both cortical and subcortical brain areas.
• These findings contribute to understanding the neurobiological changes associated with aging in the human brain.