New Delhi, Aug 16
Brain’s immune cells may explain why a fading sense of smell is an early signal for Alzheimer's disease even before cognitive impairments manifest, according to a study.
Researchers at DZNE and Ludwig-Maximilians-Universität München (LMU) in Germany revealed that the brain's immune response seems to fatally attack neuronal fibres crucial for the perception of odours.
These olfactory dysfunctions arise because immune cells of the brain called "microglia" remove connections between two brain regions, namely the olfactory bulb and the locus coeruleus, they noted in the paper published in the journal Nature Communications.
These findings, based on observations in mice and humans, including analysis of brain tissue and so-called PET scanning, may help to devise ways for early diagnosis and, consequently, early treatment.
"The locus coeruleus regulates a variety of physiological mechanisms. These include, for example, cerebral blood flow, sleep-wake cycles, and sensory processing. The latter applies, in particular, also to the sense of smell," said Dr. Lars Paeger, a scientist at DZNE and LMU.