Lifeboat Foundation

Say you live across from a bakery. Sometimes you are hungry and therefore tempted when odors waft through your window, but other times satiety makes you indifferent. Sometimes popping over for a popover seems trouble-free but sometimes your spiteful ex is there. Your brain balances many influences in determining what you’ll do. A new MIT study details an example of this working in a much simpler animal, highlighting a potentially fundamental principle of how nervous systems integrate multiple factors to guide food-seeking behavior.

All animals share the challenge of weighing diverse sensory cues and internal states when formulating behaviors, but scientists know little about how this actually occurs. To gain deep insight, the research team based at The Picower Institute for Learning and Memory turned to the C. elegans worm, whose well-defined behavioral states and 302-cell nervous system make the complex problem at least tractable. They emerged with a case study of how in a crucial olfactory neuron called AWA, many sources of state and sensory information converge to independently throttle the expression of a key smell receptor. The integration of their influence on that receptor’s abundance then determines how AWA guides roaming around for food.

“In this study, we dissected the mechanisms that control the levels of a single olfactory receptor in a single olfactory neuron, based on the ongoing state and stimuli the animal experiences,” said senior author Steven Flavell, Lister Brothers Associate Professor in MIT’s Department of Brain and Cognitive Sciences. “Understanding how the integration happens in one cell will point the way for how it may happen in general, in other worm neurons and in other animals.”

Summary: The TOB gene plays a significant role in reducing depression, anxiety, and fear in mouse models. The findings could have positive implications for developing new treatments for disorders associated with psychiatric stress.

Source: OIST

First characterized in Prof. Tadashi Yamamoto’s former lab in Japan in 1996, the gene Tob is well known for the role it plays in cancer. Previous research has also indicated that it has a hand in regulating the cell cycle and the body’s immune response.

The activity of neurons has been measured in a slice of mouse tissue using a quantum diamond sensor – and it might one day enable a new type of non-invasive brain scanning.

Summary: Determining the structure of vitronectin, a protein implicated in age-related macular degeneration and some neurodegenerative disorders, and using pressure to alter the protein shape may help in the development of new treatments for AMD.

Source: Sanford Burnham Prebys.

Research led by Sanford Burnham Prebys professor Francesca Marassi, Ph.D., is helping to reveal the molecular secrets of macular degeneration, which causes almost 90% of all age-related vision loss.

Animal studies on great apes have long been banned in Europe for ethical reasons. For the question pursued here, organoids (three-dimensional cell structures a few millimeters in size that are grown in the laboratory) are an alternative to animal experiments. These organoids can be produced from pluripotent stem cells, which then differentiate into specific cell types, such as nerve cells. In this way, the research team was able to produce both chimpanzee brain organoids and human brain organoids. “These brain organoids allowed us to investigate a central question concerning ARHGAP11B,” says Wieland Huttner of the MPI-CBG, one of the three lead authors of the study published in EMBO Reports.

“In a previous study we were able to show that ARHGAP11B can enlarge a primate brain. However, it was previously unclear whether ARHGAP11B had a major or minor role in the evolutionary enlargement of the human neocortex,” says Wieland Huttner. To clarify this, the ARGHAP11B gene was first inserted into brain ventricle-like structures of chimpanzee organoids. Would the ARGHAP11B gene lead to the proliferation of those brain stem cells in the chimpanzee brain that are necessary for the enlargement of the neocortex?

“Our study shows that the gene in chimpanzee organoids causes an increase in relevant brain stem cells and an increase in those neurons that play a crucial role in the extraordinary mental abilities of humans,” said Michael Heide, the study’s lead author, who is head of the Junior Research Group Brain Development and Evolution at the DPZ and employee at the MPI-CBG.

One of the major current theories of consciousness is that brain oscillations, also called brain waves, correlate with specific mental states. It is the synchronous waves from different regions, that is, those that are beating at the same rate, that are believed to be important for the connection of different brain regions. Brain waves have been observed for more than a hundred years, but it is still not clear exactly what they are and what they have to do with the function of the brain and the mind.

Oscillations in the brain occur because of an interplay between two forces, such as stimulation and inhibition. This dynamic can either come from two different cortical layers or a cortical and subcortical layer. Feedback properties affect the oscillations by either continuing the give and take of the two forces or changing them in various ways. Even with no outside input, the brain creates spontaneous oscillations; a well-known example is the one, connected to the thalamus and cortex, that occurs during sleep. Currently, it is believed that these oscillations help to synthesize and filter the previous day’s memories. While these oscillations are associated with sleep, most other brain oscillations are not clearly correlated with mental states.

Circa 2019 face_with_colon_three

By Tyler Benster.

Neuroscientists have a dizzying array of methods to listen in on hundreds or even thousands of neurons in the brain and have even developed tools to manipulate the activity of individual cells. Will this unprecedented access to the brain allow us to finally crack the mystery of how it works? In 2017, Jonas and Kording published a controversial research article, “Could a Neuroscientist Understand a Microprocessor?” that argues maybe not. To make their point, the authors turn to their “model organism” of choice: a MOS 6502 processor as popularized by the Apple I, Commodore 64, and Atari Video Game System. Jonas and Kording argue that for an electrical engineer, a satisfying description of the processor would break it into modules, like an adder or subtractor, and submodules, like the transistor, to form a hierarchy of information processing. They suggest that, while popular methods from neuroscience might reveal interesting structure in the activity of the brain, researchers often use techniques that would fail to reveal a hierarchy of information processing if applied to the (presumably much simpler) computer processor.

Continue reading “Can we reverse engineer the brain like a computer?” »

An alzheimer’s-proof brain: a groundbreaking case.

In a groundbreaking case researchers from the Massachusetts General Hospital have discovered a gene variant that seems to have disrupted the pathology of Tau Protein. The case of Aliria Rosa Piedrahita de Villegas.

Continue reading “Groundbreaking Alzheimer’s Case: Gene APOE3” »

Predictive models that relate brain activity to phenotype reliably fail when applied to subgroups of participants who do not fit stereotypical profiles, showing that the utility of a one-size-fits-all modelling approach is limited.