Medical Bulletin 28/December/2022

Currently, to diagnose Alzheimer's disease, clinicians use guidelines set in 2011 by the National Institute on Aging and the Alzheimer's Association. The guidelines, called the AT(N) Framework, require detection of three distinct components of Alzheimer's pathology-the presence of amyloid plaques, tau tangles and neurodegeneration in the brain-either by imaging or by analyzing CSF samples.

Unfortunately, both approaches suffer from economical and practical limitations, dictating the need for development of convenient and reliable AT(N) biomarkers in blood samples, collection of which is minimally invasive and requires fewer resources.

Reference:

Thomas Karikari et al,Brain-derived tau: a novel blood-based biomarker for Alzheimer's disease-type neurodegeneration,Brain,DOI: 10.1093/brain/awac407

Study finds apparently random baby movements to have a purpose

If you've spent time with a baby, you'll probably have noticed that they hardly keep still. Right from birth - and even in the womb - babies start to kick, wiggle and move seemingly without aim or external stimulation. These are called "spontaneous movements" and researchers believe that they have an important role to play in the development of the sensorimotor system, i.e., our ability to control our muscles, movement and coordination. If we can better understand these seemingly random movements and how they are involved in early human development, we might also be able to identify early indicators for certain developmental disorders, such as cerebral palsy.

Reference:

Hoshinori Kanazawa, Yasunori Yamada, Kazutoshi Tanaka, Masahiko Kawai, Fusako Niwa, Kougoro Iwanaga, Yasuo Kuniyoshi"Open-ended movements structure sensorimotor information in early human development". The Proceedings of the National Academy of Sciences of the United States of America. https://doi.org/10.1073/pnas.2209953120

Mechanism behind storage of remote fear memory by the brain

The brain uses distinct mechanisms to store recent versus remote fear memories. Previous studies have suggested that while the initial formation of fear memory involves the hippocampus, it progressively matures with time and becomes less dependent on the hippocampus. Much research now explains how recent fear memory is stored, but how the brain consolidates remote fear memories is not well understood.

A remote fear memory is a memory of traumaticevents that occurred in the distant past - a few months to decades ago. A University of California, Riverside, mousestudy published in Nature Neuroscience has now spelled out the fundamentalmechanisms by which the brain consolidates remote fear memories.

Reference:

Jun-Hyeong Cho et al,Neocortical SynapticEngrams for Remote Contextual Memories,Nature Neuroscience,DOI:10.1038/s41593-022-01223-1