Alzheimer’s disease: A changed perspective

Written by J The following is a guest post by J, l, i, a, m, ur, t, o, f , o, f,, u, s, , t, o, i, n ALZHEIMER’S DISEASE | Study reveals…

Alzheimer's disease: A changed perspective

Written by J

The following is a guest post by J, l, i, a, m, ur, t, o, f , o, f,, u, s, , t, o, i, n

ALZHEIMER’S DISEASE | Study reveals how disease progresses in the brain

The story of Alzheimer’s disease is a tale of vast scientific transformation.

Just two decades ago, the understanding of the genetic and structural causative factors underlying Alzheimer’s disease was poorly understood. Several clinical trials of therapeutic interventions — at best, modestly effective — were failed, and even in the absence of new knowledge, the prevailing medical theory of Alzheimer’s was that there was no known “cure.” This did not represent an encouraging prediction for those in dire need of Alzheimer’s diagnosis and treatment.

Today, we have an entire new approach to understanding Alzheimer’s disease. Although its causes are still elusive, we have discovered important biological markers and molecular relationships that are more specific than the historical phenomenology of Alzheimer’s disease. In addition, the majority of recent Alzheimer’s trials have yielded positive results, including a placebo-controlled, one-year trial that achieved a significant reduction in memory loss.

Is cancer similarly advancing with new molecular understanding?

In fact, in most ways, Alzheimer’s disease is ahead of cancer — in both respect to its scientific understanding and effective therapeutic treatments. There is substantial interest now in the field of cancer immunotherapy (also known as T-cell therapy), which seeks to use immune cells to re-purpose their roles as anti-cancer mediators in fighting tumors.

While cancer is caused by a complex array of genes and genetic abnormalities, the molecular mechanisms underlying Alzheimer’s disease are more clear-cut. And the advances in understanding are even more striking when compared to other forms of mental illnesses. Adherents to Alcoholics Anonymous or other substance treatment programs are extremely fortunate that they are not subjected to cognitive decline following their treatment.

Alzheimer’s disease (AD) is characterized by memory problems, or “brain fog,” and its incidence and progression are increasingly studied as diagnostic indicators of neurodegeneration. Researchers in molecular biology and developmental biology now believe that we are beginning to detect specific structural changes in the brain that are associated with AD.

A study published earlier this month in the journal Neuron reveals that the structures of the brain involved in memory in brain-damaged Alzheimer’s patients seem to gradually lose cell function and function. Alzheimer’s appears to involve a “ripple effect” of failures in neuronal signaling networks, creating a subtle accretion of synaptic disturbances. The signal loss seems to disrupt the molecular machinery of critical brain regions that are involved in memory formation and memory consolidation.

The recent findings from the current study indicate that deficits in the ability of brain cells to maintain connections and communicate in this fragmented cell architecture directly contributes to memory deficits. This view is consistent with previous experiments of clumping of the amyloid-beta substance, identified as a hallmark of Alzheimer’s disease, in the developing brain as young individuals age. These results are interesting but do not tell us whether such signals cause memory impairment. For this, additional studies are required.

Future research also suggests that changes in the brain arise with dementia and progressively get worse. Memory problems are thought to remain stable throughout life.

Early stages of dementia occur when memory and other cognitive functions of a patient are already at the low level characteristic of memory impairment. There is no cognitive ability increase until later stages of dementia. This is why memories acquired years ago appear to be relatively stable over time, but cognitive function later on deteriorates rapidly.

Neurodegeneration is accompanied by changes in lifestyle and in the environment. During these periods, symptoms can disappear on the surface, but the more persistent memory impairment remains. Persons with Alzheimer’s disease appear to exhibit both impaired memory in early stages of dementia and brain shrinkage — loss of neurons and other tissue — in later stages of the disease. So those with early, but significant, memory problems may seem to recover during phases of the disease but are still impaired.

The research now unfolding on Alzheimer’s is a completely new approach that is simultaneously exciting and disturbing. Scientists, including my colleagues at the Division of Brain Sciences at the Center for Neurodegenerative Diseases at Massachusetts General Hospital, are living up to their promise to address the “tipping point” — when there is detectable deterioration in the brain but there is no detection of disease symptoms by trained clinicians. Indeed, once the human brain reaches a crucial point of decline, it usually slips into irreversible loss, and memory loss soon thereafter.

Leave a Comment