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Archive for the ‘neuroscience’ category

Dec 25, 2024

ADULT NEUROGENESIS IN HUMANS: A Review of Basic Concepts, History, Current Research, and Clinical Implications

Posted by in categories: biotech/medical, neuroscience

The evidence presented by Boldrini et al2 was considered resilient and convincing because the authors ensured that the samples were taken from healthy individuals using more biological parameters, such as angiogenesis and change in volume of DG, for a suitable comparison. They also employed unbiased stereology, which is the gold standard for counting number of neurons.2

The contrary results presented by the Sorrels study and Boldrini study highlight the existing ambiguity regarding the concept of neurogenesis in adult humans. Both studies employed reasonably similar immunohistological methods and included many of the same neurogenesis markers, yet contrasting results were observed. The study by Boldrini et al examined samples from humans aged 14 to 79 years, finding more than a thousand cells in each part of the DG, which was in stark contrast to what was observed by Sorrells et al, who found very few cells in the neurogenic niche of subjects in the same age range. Even if we consider that some discrepancies in numbers might arise due to the difference in counting methods (or subjective reasons), such marked and obvious disparity is perplexing. Sorrels et al justified their findings, noting the limitation that relying solely on the presence of markers might cause glial lineage cells to be identified as neuronal lineage cells. However, the authors stated that they used additional methods for confirmation, including transmission electron microscopy (TEM)-immunogold and in-situ hybridization. The relative paucity of any type of progenitor or immature cells, including glia in the neurogenic niche of DG in their study, remains unexplained.

Kempermann et al7 expressed skepticism regarding the negative findings of Sorrells et al, naming the postmortem interval, the lack of known status regarding neuropsychiatric disease or chronic ailment, and using patients with epilepsy as key factors of concern.7 Kempermann et al argued that, in severe epilepsy, destruction of the neurogenic niche is an explicit possibility, and that, in some cases, epilepsy could be the reason for the lack of neurogenesis.7 Additionally, Kempermann et al also criticized the use of 10% formalin in some of the samples due its potential to mask the expression of proteins.7 However, Sorrells et al clearly mentioned that they performed appropriate antigen retrieval for the selected sections.1 Kempermann et al7 suggested that dependence on the protein markers to denote neurogenesis could be an erroneous approach and that some of the markers, such as DCX, are known for fast degradation. Additionally, the presence of DCX-negative immature neurons and high inter-individual variation in expression of DCX in humans, which was also reflected in the data presented by Boldrini et al, are not unusual.7 The use of fluorescence markers also was presented as a caveat by Kempermann et al7 because it is prone to fade away and might give rise to false negative impression.

Dec 25, 2024

Stem cells head to the clinic: treatments for cancer, diabetes and Parkinson’s disease could soon be here

Posted by in categories: bioengineering, biotech/medical, life extension, neuroscience

Andrew Cassy had spent his working life in a telecommunications research department until a diagnosis of Parkinson’s disease in 2010 pushed him into early retirement. Curious about his illness, which he came to think of as an engineering problem, he decided to volunteer for clinical trials.

“I had time, something of value that I could give to the process of understanding the disease and finding good treatments,” he says.

In 2024, he was accepted into a radical trial. That October, surgeons in Lund, Sweden, placed neurons that were derived from human embryonic stem (ES) cells into his brain. The hope is that they will eventually replace some of his damaged tissue.

Continue reading “Stem cells head to the clinic: treatments for cancer, diabetes and Parkinson’s disease could soon be here” »

Dec 24, 2024

Tiny, wireless antennas use light to monitor cellular communication

Posted by in categories: biotech/medical, neuroscience

Monitoring electrical signals in biological systems helps scientists understand how cells communicate, which can aid in the diagnosis and treatment of conditions like arrhythmia and Alzheimer’s.

But devices that record electrical signals in cell cultures and other liquid environments often use wires to connect each electrode on the device to its respective amplifier. Because only so many wires can be connected to the device, this restricts the number of recording sites, limiting the information that can be collected from cells.

MIT researchers have now developed a biosensing technique that eliminates the need for wires. Instead, tiny, wireless antennas use light to detect minute electrical signals.

Dec 24, 2024

What the Tip-of-the-Tongue Phenomenon Says About Cognitive Aging

Posted by in categories: life extension, neuroscience

While word-finding failures can be taken as evidence of memory problems, they may not be harbingers of befuddlement after all.

Dec 24, 2024

Clinical trial shows propranolol reduces tremors in Parkinson’s disease

Posted by in categories: biotech/medical, neuroscience

The standard medication levodopa does not always work against tremors in Parkinson’s disease, especially in stressful situations. Propranolol, however, does work during stress, providing insight into the role of the stress system in tremors. MRI scans reveal that propranolol directly inhibits activity in the brain circuit that controls tremors. Doctors may consider this medication when levodopa is ineffective.

People with Parkinson’s disease report that worsen during stressful situations. “Tremors act as a sort of barometer for stress; you see this in all people with Parkinson’s,” says neurologist Rick Helmich from Radboud university medical center.

The commonly used drug levodopa usually helps with tremors, but it tends to be less effective during stress, when tremors are often at their worst. Helmich and his team wanted to investigate whether a medication targeting the stress system could help and how this effect of stress on tremors works in the brain. The work is published in the journal Annals of Neurology.

Dec 24, 2024

Long COVID: SARS-CoV-2 Spike Protein Accumulation Linked to Long-lasting Brain Effects

Posted by in categories: biotech/medical, neuroscience

Researchers from Helmholtz Munich and Ludwig-Maximilians-Universität (LMU) have identified a mechanism that may explain the neurological symptoms of long COVID.

The study shows that the SARS-CoV-2 spike protein remains in the brain’s protective layers, the meninges, and the skull’s bone marrow for up to four years after infection. This persistent presence of the spike protein could trigger chronic inflammation in affected individuals and increase the risk of neurodegenerative diseases.

The team, led by Prof. Ali Ertürk, Director at the Institute for Intelligent Biotechnologies at Helmholtz Munich, also found that mRNA COVID-19 vaccines significantly reduce the accumulation of the spike protein in the brain. However, the persistence of spike protein after infection in the skull and meninges offers a target for new therapeutic strategies.

Dec 24, 2024

Alzheimer’s disease mortality among taxi and ambulance drivers: population based cross sectional study

Posted by in categories: biotech/medical, neuroscience

Objective To analyze mortality attributed to Alzheimer’s disease among taxi drivers and ambulance drivers, occupations that demand frequent spatial and navigational processing, compared with other occupations.

Design Population based cross-sectional study.

Setting Use of death certificates from the National Vital Statistics System in the United States, which were linked to occupation, 1 January 2020–31 December 2022.

Dec 24, 2024

Can Gene Therapy Treat Chronic Pain?

Posted by in categories: bioengineering, biotech/medical, genetics, neuroscience

Sometimes pain is a necessary warning signal; for example, if we touch something very hot and it burns, we know to move our hand away. But chronic pain can destroy a person’s quality of life, and it can be extremely challenging to get relief. Some researchers have been searching for ways to deactivate pain receptors, so the body no longer feels the neural signals of chronic pain. Using mouse models of acute inflammatory pain, scientists have shown that it is possible to deactivate pain receptors with genetic engineering tools. The work has been reported in Cell.

“What we have developed is potentially a gene therapy approach for chronic pain,” said senior study author Bryan L. Roth, MD, PhD, a distinguished professor at the University of North Carolina (UNC) School of Medicine, among other appointments. “The idea is that we could deliver this chemogenetic tool through a virus to the neurons that sense the pain. Then, you could just take an inert pill and turn those neurons off, and the pain will literally disappear.”

Dec 24, 2024

Research Finds Vaccines Are Not Behind the Rise in Autism. So What Is?

Posted by in categories: biotech/medical, neuroscience

What causes autism? It isn’t vaccines, studies show. Here are some possibilities that researchers are exploring.


There is no one factor that causes autism — or explains its growing prevalence. Researchers are seeking explanations for the surge. Here are some possibilities.

Dec 24, 2024

Alzheimer’s progression tied to stress-induced microglial lipid release

Posted by in categories: biotech/medical, health, neuroscience

Researchers with the Advanced Science Research Center at the CUNY Graduate Center (CUNY ASRC) have unveiled a critical mechanism that links cellular stress in the brain to the progression of Alzheimer’s disease (AD).

The study, published in the journal Neuron, highlights microglia, the brain’s primary immune cells, as central players in both the protective and harmful responses associated with the disease.

Microglia, often dubbed the brain’s first responders, are now recognized as a significant causal cell type in Alzheimer’s pathology. However, these cells play a double-edged role: some protect brain health, while others worsen neurodegeneration.

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