Biggest Breakthroughs in Biology and Neuroscience: 2023

The line between imagination and reality has long been the realm of cinematic and literary exploration. But now, thanks to research published in 2023, Scientists are gaining new insights into one of the most mysterious transitions in human consciousness - the shift from reality based perception to internal, imaginative brain states. Imagination really allows you to come up with what things would be like in alternative realities, which is something that's really powerful.

It can help you plan things. You can imagine, okay, if I'm going to have this dinner, what's what is it going to taste like? If that's something I like?

Okay, well, then let me go and make that for dinner, for example. So it allows you to really like, plan your future. it's just interesting to know how your brain distinguishes internally generated content from stuff that is out there in the world.

But scientists have long struggled to understand the puzzling neuroscience behind our ability to distinguish between perception and imagination, since both use many of the same parts of the brain. in 1910, psychologist Mary Perky was trying to develop a scientific definition of imagination. So she devised an experiment that produced a surprising result.

Test subjects were asked to stare at a blank wall and imagine a certain fruit. Meanwhile, behind the scenes, Perky projected a very faint image of the fruit on the wall. When asked if they saw anything real, the participants were sure they hadn't, although they commented on how vivid the image they were imagining seemed.

Perky concluded that when our perception of something matches what we're imagining, we will assume we've imagined it. This would eventually come to be known as the Perky effect. Since then there's been a handful of studies that tried to replicate it, but the results were very mixed, Nonetheless, decades kind of with the advancement of neuroimaging, we've shown time and time again that when we imagine something many of the same brain processes becoming involved as when we would actually see that same thing.

So Dykstra and her team designed an updated version of Perky's experiment. The setup was similar. But to better control for the variability in imagined objects, the researchers asked participants to imagine something more specific: diagonal lines.

Participants stared at a static screen and were asked to imagine the lines, just as in Perky's experiment, faint images would appear and disappear. What we found was actually kind of surprising because we did not find a Perky effect. instead, in results published in 2023, a more nuanced picture emerged.

When the researchers asked participants if the lines they saw were real or imagined, the responses varied. When they were shown faint images of the lines. Participants were more likely to report seeing them, and when they weren't shown the lines.

some still reported seeing them suggesting vivid imaginations at work. So taken together, what we can kind of conclude from this is that when imagination gets really vivid, it can be mistaken for reality. so the way that we are thinking about this now is that this is all to do with sensory strength.

Unlike perky, Dykstra went beyond first person reporting. She and her collaborators analyzed neuroimaging data from the participants in their study. What they saw suggests that the visual and prefrontal cortices may be directly involved in the process of distinguishing imagination from reality.

So I intuitively always thought it was going to be more like a switch. But the research seems to suggest that it might be more like a gradual meter. But then the way you're interpreting this is more binary.

So like once it crosses some threshold, you're like, now it's real, and before that it's not real. And that point is what we call the reality threshold. And they're basically saying that the way that we distinguish what is seen versus what is imagined, that strength of this representation.

has to exceed the threshold for us to consider it real or out there in the world. And that's something that we're really keen to investigate further, whether we can get measures of this in individual people and then see if that relates to things like hallucination proneness or schizophrenia or sometimes in Parkinson's, people experience these really vivid hallucinations that are actually imaginations, but they feel real to these people. So one hypothesis would be that something is wrong in their reality threshold the more I learn, the more questions I have and the more I want to keep going.

Humans are made of nearly 70 trillion cells, but only half of them are truly ours. The other half are foreign microbes, collectively called the human microbiome. Covering us inside and out, this intricate ecosystem helps us digest food and fight off disease.

Even though the microbiome is an essential part of who we are, it's still largely a mystery to science. Researchers have been trying to better understand how we acquire these foreign microbes and if they're exchanged freely between people like other germs. So we say microbiome, but this means many different species, hundreds to thousands.

So it's not just studying one pathogen, we have to study so many microorganisms, all of them are different These organisms vary in terms of their genomes, their functions, what they're doing, why they're there, how they interface with the human body. And that presents a lot of different challenges how to grow these organisms, how to study their different and various functions. There's another reason our microbiome is tricky to study.

Its inhabitants are constantly changing. At birth we have an imprinting of the bacteria from the and from the environment. And then we continuously update, improve, change, modify our microbiome during all our lifetime.

This year, a team of biologists at the University of Trento in Italy developed new ways to trace genetic strains of microbes as they pass between individuals. So we try to collect as many samples as possible to get a global understanding of microbiome transmission in the different lifestyles in the planet. We collected more than 9000 samples for the gut and the microbiome, so stool and saliva samples in more than 30 different countries.

We just sequence all the DNA that's there in the sample. The challenge here is to make sense of the sequencing data, considering that we are not looking at one individual but a community of individuals all together. Comparing the individual's data across familial and social networks, the researchers wanted to know if microorganisms in the microbiome could spread from person to person, like a cold or a stomach bug.

And what they found suggests that microbes hop much more extensively than we thought between people in close physical proximity, like roommates, spouses and children. The power of our study was really that what we saw was consistent across all these populations and different lifestyles. There is really a massive transmission of human microbiome members directly through social interactions.

So our social activity impacts our microbiome, which in turn impact our biology. So, the way and the people we interact with is impacting our biology, our medical history. I think it warrants additional study into the dynamics and the true sources and the full range of sources where these organisms come from.

But this is a huge step in understanding the transmission landscape. As humans evolved, our microbiomes may have evolved with us to protect our health and immunity. But with the continued use of antibiotics and antiseptics in the modern world, we may be throwing off our body's natural microbial balance and leaving ourselves.

more susceptible to the health risks. The more we study it, the more we realize that the microbiome underlies a lot of different immune related disorders in the body. So many of these are chronic conditions, things like cancers, autoimmunity inflammatory bowel disease and diabetes, multiple sclerosis and many other disorders.

And so we typically didn't understand the root causes of those diseases. But as we explore them more, they're not only genetic and environmental, but they have a lot to do with these organisms that live within our body. We cannot fully infer causality, so we don't know if the disease occurs first of them or the microbiome alterations.

And so it's very important to us to understand how we acquired this bacteria and how we transmit them to other individuals. This is a human embryo. This is a mouse embryo.

They both start growing and building a body in much the same way. But then something strange happens, the human embryo's development slows down and the mouse's accelerates. As far as we can tell, every step takes about 2 to 3 times longer in the human embryo than a in the mouse embryo.

How and when different embryonic tissues develop can dramatically alter an organism's form. But a mystery persists. What controls this difference in timing?

New evidence suggests the mysterious conductor driving development is an organelle scientists may have written off as a one trick pony. So when people think about mitochondria, traditionally, they think about the powerhouse of the cell, which is producing ATP to provide energy for studying our functions. But they're also involved in signaling, there is a lot more going on in mitochondria than just energy production.

To figure out the causal relationship between activity in the mitochondria and the timing of embryonic development. researchers at Harvard Medical School, manipulated different regions within the mitochondria of human and mouse stem cells. and in early 2023, they published their results.

So we observe that mouse cells produce protein faster through the process of mRNA translation than human cells. And we found that if we experimentally increased the activity of mitochondria, we could also force the cells to produce protein faster and develop faster. This finding was then echoed by a team of researchers working in Belgium in a paper they published in Science just weeks later, which pointed towards the mitochondria's role in developmental timing in the nervous system.

Mitochondria is important in many aspects. Just not only the ATP protein and the metabolite production. And the what we found is a mitochondria is a working as a pacemaker of the speed of the development in cells.

I think very important next question is how mitochondrial activity regulate gene regulatory network because gene regulatory network is also important to regulate the timing of that development. This research could have major implications for cell therapy, which is when damaged cells are replaced by healthy cells, and cancer research. If we can find a way by setting developmental speed to accelerate the production of cells for therapies, then that would be really important in accelerating the cell therapy revolution.

Tempo is important to make up different outcome. That's why mitochondria is that important pacemaker and the make a diversity of our animal kingdom. So they have out this kind of as a function as a driving force of the evolution.