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How sense of smell is linked with cognition

Researchers have demonstrated for the first time a way to monitor inhibitory neurons that link sense of smell with memory and cognition in mice.

Scientists from Cold Spring Harbor Laboratory (CSHL), led by Assistant Professor Stephen Shea, was able to measure the activity of a group of inhibitory neurons that links the odor-sensing area of the brain with brain areas responsible for thought and cognition. This connection provides feedback so that memories and experiences can alter the way smells are interpreted.

She worked with lead authors on the study: Brittany Cazakoff, graduate student in CSHL’s Watson School of Biological Sciences, and Billy Lau, PhD, a postdoctoral fellow to engineer a system to observe granule cells for the first time in awake animals.
Granule cells relay the information they receive from neurons involved in memory and cognition back to the olfactory bulb.

There, the granule cells inhibit the neurons that receive sensory inputs. In this way, “the granule cells provide a way for the brain to ‘talk’ to the sensory information as it comes in,” explains Shea. “You can think of these cells as conduits which allow experiences to shape incoming data.”

Soon, personalised medicines could help cure diseases

Researchers have developed a new methodology for rapidly measuring the level of antibiotic drug molecules in human blood serum, paving the way to applications within drug development and personalised medicine.

When effective, antibiotic molecules impose cellular stress on a pathogen's cell wall target, such as a bacterium, which contributes to its breakdown. However, competing molecules in solution, for example serum proteins, can affect the binding of the antibiotic to the bacterium, reducing the efficacy of the drug. Serum proteins bind to drugs in blood and, in doing so, reduce the amount of a drug present and its penetration into cell tissues.

As the amount of antibiotics that bind to serum proteins will vary between individuals, it is extremely valuable to be able to determine the precise amount of the drug that is bound to serum proteins, and how much is free in the blood, in order to be able to accurately calculate the optimum dosage.

Existing biosensors on the market do not measure cellular stress, however, the nanomechanical sensor exploited by a group of researchers from the London Centre for Nanotechnology (LCN) at UCL, the University of Cambridge, the University of Queensland and Jomo Kenyatta University of Agriculture and Technology, can accurately measure this important information even when antibiotic drug molecules are only present at very low concentrations.

The researchers coated the surface of a nanomechanical cantilever array with a model bacterial membrane and used this as a surface stress sensor. The sensor is extremely sensitive to tiny bending signals caused by its interactions with the antibiotics, in this case, the FDA-approved vancomycin and the yet to be approved oritavancin, which appears to deal with certain vancomycin-resistant bacteria, in the blood serum.

This investigation has yielded the first experimental evidence that drug-serum complexes (the antibiotics bound to the competing serum proteins) do not induce stress on the bacteria and so could provide realistic in-vitro susceptibility tests for drugs and to define effective doses which are effective enough but less toxic to patients.

HIV vaccine comes closer to reality

A research team has found how the immune system makes a powerful antibody that blocks HIV infection of cells by targeting a site on the virus called V1V2.
Analyses of the results of a clinical trial of the only experimental HIV vaccine to date to have modest success in people suggest that antibodies to sites within V1V2 were protective.

The new findings point the way toward a potentially more effective vaccine that would generate V1V2-directed HIV neutralising antibodies.

The study led by scientists from the National Institute of Allergy and Infectious Diseases (NIAID) began by identifying an HIV-infected volunteer in the CAPRISA cohort who naturally developed V1V2-directed HIV neutralising antibodies, named CAP256-VRC26, after several months of infection.

Using techniques similar to those employed in an earlier study of HIV-antibody co-evolution, the researchers analysed blood samples donated by the volunteer between 15 weeks and 4 years after becoming infected. Notably, the study revealed that after relatively few mutations, even the early intermediates of CAP256-VRC26 can neutralise a significant proportion of known HIV strains.

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