Question

How genes do affects the ageing of the brain?

Answer 1

The effects of ageing on the brain and cognition are widespread and have multiple etiologies. Brain ageing has its effects on cells, morphology, vasculature and cognition. Genetics, neurotransmitters, hormones, and experience all have a part to play in brain ageing. Genetics play vital role in ageing of brain.

BDNF (Brain - derived neurotrophic factor) is a brain based protein which is an important genetic factor helps to maintain existing neurons and encourages the growth of new neurons abd synapse.

The human brain shows a decline in function and a change in gene expression. This modulation in gene expression may be due to oxidative DNA damage at promoter regions in the genome. Genes that are down-regulated over the age of 40 include:

• GluR1 AMPA receptor subunit
• NMDA R2A receptor subunit (involved in learning)
• Subunits of the GABA-A receptor
• Genes involved in long-term potentiation e.g. calmodulin 1 and CAM kinase II alpha.
• Calcium signaling genes
• Synaptic plasticity genes
• Synaptic vesicle release and recycling genes

Supportive literature reviews:

1. The study was published online in the journal Cell Systems.

"If you look at a group of seniors, some will look older than their peers and some will look younger," said the study's co-leader Asa Abeliovich, PhD, professor of pathology and neurology in the Taub Institute for Alzheimer's Disease and the Aging Brain at CUMC. "The same differences in aging can be seen in the frontal cortex, the brain region responsible for higher mental processes. Our findings show that many of these differences are tied to variants of a gene called TMEM106B. People who have two 'bad' copies of this gene have a frontal cortex that, by various biological measures, appears 12 years older that those who have two normal copies."

2. Studies have identified individual genes that increase one's risk for various neurodegenerative disorders, such as apolipoprotein E (APOE) for Alzheimer's disease. "But those genes explain only a small part of these diseases," said study co-leader Herve Rhinn, PhD, assistant professor of pathology and cell biology in the Taub Institute. "By far, the major risk factor for neurodegenerative disease is aging. Something changes in the brain as you age that makes you more susceptible to brain disease."