Recent research supported by the National Institutes of Health (NIH) utilizing advanced neuroimaging technologies suggests Alzheimer’s disease may inflict damage on the brain in two distinct stages. The investigators behind this paradigm-shifting discovery describe an initial phase that progresses insidiously and asymptomatically, targeting a select few susceptible neuronal types. This phase remains undetected as individuals display no cognitive deficits. In stark contrast, the subsequent phase ushers in widespread neural devastation, aligning with the emergence of clinical symptoms and the accelerated build-up of amyloid plaques, neurofibrillary tangles, and other pathological features emblematic of Alzheimer’s.
Dr. Richard J. Hodes, M.D., director of the NIH National Institute on Aging, stressed the significance of these findings, “One of the hurdles in addressing Alzheimer’s has been that extensive brain damage occurs long before symptoms manifest. The capacity to identify these early alterations paves the way for novel insights into what transpires in a patient’s brain during the preclinical stages of the condition.”
He further iterated that the insights gleaned from this study profoundly modify the scientific comprehension of Alzheimer’s neurodegeneration and will inform the creation of innovative therapeutic strategies to combat this crippling ailment.
The team conducted a scrutiny of brain specimens from 84 individuals. The illuminating study, documented in the journal Nature Neuroscience, proposes that initial harm to a particular class of cells known as inhibitory neurons may incite the synaptic dysfunctions at the core of the disease’s pathology. Moreover, the investigation not only corroborated previous conceptions of the neurodestructive processes at play in Alzheimer’s but also unveiled a myriad of novel alterations potentially implicated in the disease’s progression.
Revolutionary research funded by the National Institutes of Health (NIH) and employing advanced neuroimaging techniques reveals a concept that Alzheimer’s disease may ravage the brain in two distinct stages. The initial phase progresses stealthily, targeting specific vulnerable neuron types without triggering any cognitive symptoms. In stark contrast, the second phase is characterized by extensive brain damage that coincides with the onset of clinical symptoms and the rapid accumulation of classic Alzheimer’s pathologies.
Dr. Richard J. Hodes, M.D., director of the NIH National Institute on Aging, underscores the breakthrough, stating, “One of the greatest challenges in battling Alzheimer’s has been diagnosing and treating it before pronounced brain damage is already done. Detecting these early, subtle changes is a monumental leap forward, as we may now observe the earliest stages of the disease within the brain.”
In a meticulous examination of brain tissue from 84 individuals, researchers published their findings in Nature Neuroscience, suggesting that early damage to a subset of neurons, known as inhibitory neurons, could trigger the synaptic dysfunction fundamental to Alzheimer’s pathology. The study not only reinforces existing theories about the degenerative processes of Alzheimer’s but also reveals a complex array of previously unknown brain alterations which may contribute to the progression of the disease.
The latest discovery upended the researchers’ expectations. Conventionally, the scientific community believed that Alzheimer’s preferentially targets excitatory neurons, which are responsible for sending stimulatory signals across the neural network. However, inhibitory neurons, recognized for transmitting signals that quell neural activity, have now been implicated as well. The authors of the study speculated on the critical loss of SST inhibitory neurons and how this detriment could instigate a cascade of alterations within the brain’s circuitry, laying the groundwork for Alzheimer’s pathology.