Disembodied Voices: Haunting Hallucinations and Their Origins

Do people actually hear voices, or are the sounds just figments of their imagination? Those who truly hear disembodied voices are likely experiencing a particular type of hallucination. Historically, hallucinations have been a powerful tool in storytelling, popping up in everything from the Euripides’ Greek tragedies to Shakespeare’s plays and more modern-day stories of demonic possession [12]. Sometimes these voices appear to have good intentions, like those which inspired Joan of Arc, while others seem to taunt or even torture, like those which ‘possess’ their victims, forcing them to do unthinkable things [3]. Hallucinations have captivated us for centuries, but the neurobiological basis for these phenomena is not well understood.

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Of Songs and Circuits: Freshly Made Neurons Make For Freshly Made Music

Image Credit: “WHITE-CROWNED SPARROW” by Gary L. Clark is licensed under CC-BY-SA-4.0.

The study of how new neurons are made in the adult brain (adult neurogenesis) has received much attention because newborn neurons can integrate into and reshape preexisting neural circuits, making circuits “plastic.” It's not clear, though, how neural plasticity relates to the behavior produced by a particular neural circuit. Songbirds exhibit seasonal plasticity: during breeding season they have an increased number of neurons called Higher Vocal Center neurons (HVCs), which connect different regions of the brain important for producing songs. The relationship between cyclic addition/removal of HVC neurons and song production in male white-crowned sparrows was addressed by Rachel Cohen and colleagues. To compare the number of newly added HVC neurons to song quality in breeding versus non-breeding sparrows, they first had to count the number of newly added HVCs. They then compared this to the types of songs the sparrows sang. Cohen and colleagues found a direct correlation between song structure and HVC neuron number. When HVC neuron number goes down, song structure degrades (corresponding to non-breeding birds), but as new HVCs are added, song structure recovers (corresponding to breeding birds). Generation of new HVC neurons was also correlated to increases in the amount of a steroid hormone known to be important for neuron survival. The authors provide highly suggestive evidence that the underlying basis for circuit plasticity in this song circuit is the regeneration of HVC neurons, a process controlled by hormones. The seasonal plasticity of songbird neural circuits may also serve as a new model for understanding how number of neurons and the connections they make produces specific types of behaviors.

Jennifer Lovick (@drjkyl)
Senior Editor, Science in Entertainment, Signal to Noise Magazine
PhD, Molecular, Cell, and Developmental Biology

References:

Cohen, R.E., Macedo-Lima, M., Miller, K.E., Brenowitz, E.A. Adult neurogenesis leads to the functional reconstruction of a Telencephalic neural circuit. J Neurosci 36, 8947-8956 (2016).

Molecules, Motors, and Chemists: The Story of a Nobel Prize that Combines Ingenuity and Imagination

Molecules, Motors, and Chemists: The Story of a Nobel Prize that Combines Ingenuity and Imagination

This year’s Nobel Prize in Chemistry was awarded to three outstanding scientists for revolutionizing the field of nanomachines. To put this in perspective, for a person to be on the same scale as one of these machines, they would have to shrink approximately one billion times, putting them on the same scale as atoms and molecules. The ingenuity, creativity and imagination of Drs. Sauvage, Stoddart, and Frenga is reflected in their work constructing precise molecular structures, including rotating molecular rings, nanomotors, and nanocars.

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Autopsy of a Transcriptome: Zombie Genes and the Non-Believers

Autopsy of a Transcriptome: Zombie Genes and the Non-Believers

What does it mean for our cells to be alive after we are no longer living? Some researchers believe they may have found a way to answer this question using genomics. Enter the thanatotranscriptome and the discovery of zombie genes, genes that “wake up” in our cells after we die. 

What’s notable about this paper is not the paradigm-shifting finding that zombie genes may exist, but that unbeknownst to the public, the scientific community actively retaliated against the supposition. 
 

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I, Cannibal: The Critical Role of Autophagy In Human Physiology

I, Cannibal: The Critical Role of Autophagy In Human Physiology


Now that the world is aware of this strange scientific term and Hollywood filmmakers have begun dreaming up ways to incorporate the terrifying idea of cellular cannibalism into their latest blockbuster horror films, the time seems right to answer some pressing questions about autophagy, and why it is important enough to have been honored with the 2016 Nobel prize in medicine.

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Cadaver Exome Sequencing Brings Modern Medicine to Anatomy 101

Modern genetics is finally finding its way into medical school.

Following our advances in understanding the human genome during the last 30 years, American medical education is entering an era of change, where the practice of genetics and genomic medicine is increasingly shaping the new landscape of physician training. Recognized nationally as an important education initiative, genomic medicine programs are being introduced by medical schools across the country into first- and second-year curriculum. The goal is to train the next generation of physicians to understand how to utilize genomic technology and what insights it can offer for a patient's condition; however, study of this complicated and highly personal (and some argue, private) data can be difficult to incorporate into the classroom.

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Aquamess: Portraits of Garbage from the Top of the World

Aquamess: Portraits of Garbage from the Top of the World

Of all the garbage we collected in the extreme north, the most unexpected pieces were children's toys. I wanted to imagine the high Arctic as pristine, with endless white vistas. Yet on beautiful forlorn shores of Svalbard, Norway's Arctic archipelago, we spotted our remnants - a mustard bottle, a cigarette lighter, a slipper, an asthma puffer, and plastics galore. In Svalbard's most remote lands you see more polar bear paw prints than human footprints - but you also see our human synthetic waste.

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Repair A Broken Heart with Your Skin

Images compiled by Xin Liu.

When all other treatments fail, heart failure patients may be treated with a heart transplant, but finding a genetically matched donor can take more time than the patient has remaining. For decades, medical researchers have been asking whether we can find an alternative to repair a broken heart. It turns out the remedy may lie in patients’ own cells: through the process of transdifferentiation, we can transform one type of cell into another. The new cells can then be transplanted into the damaged heart. A recent experiment discovered that a cocktail of nine chemicals, “9C,” can transform cells efficiently [1]. Scientists grew human skin fibroblasts—an abundant cell type that maintain the layered structure of skin—in a petri dish with 9C and other molecules that encourage cardiac cell growth. After a period of time, the fibroblasts turned into heart muscle cells: they gathered into well-organized stripes, they contracted together the way a complete heart beats, and they successfully repaired a damaged heart when transplanted into a mouse. These morphological and functional changes may be caused by the ability of 9C to alter genomic structures and gene expression. DNA is normally wound tightly around protein molecules, keeping it compact; 9C can loosen these structural proteins, allowing the activation of genes essential for heart function. Compared to prior genetic engineering methods, this chemical method drastically improves the efficiency of transdifferentiation. While the standard genetic engineering method only converted 0.1% of fibroblasts into cardiac cells, 9C could convert more than 97% of the cells [2]. Although this method is still in its infancy, these results suggest it may be a promising approach to healing heart failure.

Xin Liu
Guest Contributor
PhD Candidate, Molecular Biology Interdepartmental Doctoral Program, UCLA
 

References
[1] Cao, N. et al. Conversion of human fibroblasts into functional cardiomyocytes by small molecules. Science, 352, 1216–1220 (2016).
[2] Srivastava, D. et al. Recent advances in direct cardiac reprogramming. Current Opinion in Genetics & Development 34, 77–81 (2015).

 

3D Bioprinting Human Tissues, One Layer of Cells at a Time

3D Bioprinting Human Tissues, One Layer of Cells at a Time

In 2011, the Congressional Budget Office reported that over 1,000 American soldiers required an amputation, due in large part to improvised explosive devices. Some lost legs; gone are the feelings of an ocean washing over their feet. Others, an ear, binding them to auditory imperfection and forever altering their mirrored reflection. But must these losses last forever? The integration of stem cell science with new tissue fabrication techniques is tantalizingly close to achieving a feat seemingly pulled from the pages of science fiction. Can we regrow those soldiers’ limbs and ears?

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Jupiter Ascending: The Historic Arrival of the Juno Spacecraft at Jupiter

Jupiter Ascending: The Historic Arrival of the Juno Spacecraft at Jupiter

On July 4th, at 10:30 pm (EST), the spacecraft Juno will arrive at Jupiter after a five year and nearly two billion mile journey. It will circle the planet 37 times, collecting a variety of data, before falling into the atmosphere and destroying itself. Funded by NASA, built by Lockheed Martin in Denver, and operated by JPL in Pasadena, the Juno spacecraft will observe Jupiter like never before, flying closer and orbiting longer than any orbiter in NASA history.

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A Primer on Time Travel (And Why You'll Never Get to Do It)

A Primer on Time Travel (And Why You'll Never Get to Do It)

The Planet of the Apes scenario is a dramatized version of the so-called “Twin Paradox.” The Twin Paradox is a well-known problem posed to students of physics and relativity. Imagine two twins decide to join NASA. One twin is sent on a mission into space, while the other stays home. The traveling twin goes 10 light years (~60 trillion miles) away, turns around, and comes back. Upon his arrival, the traveling twin is several years younger than the twin that stayed on Earth. How did this happen? This article explains the Twin Paradox, and how space travel can be used to travel to the future! 

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Zombie Genes: New Evidence Points to Genetic Life After Death

Image credit: “Internal anatomy of a fish (cutaway diagram)” by Alberto Rava is in the public domain. “A section of DNA” by Michael Ströck is licensed under CC Attribution-ShareAlike 3.0. Images modified by Malika Kumar.

What does it mean to die? The exact nature and definition of death has been a mysterious and often hotly debated topic since the times of the earliest human cultures. In a new study from the University of Washington in Seattle, a group of scientists has shown that the lives of our genes may far outlast our own lives [1].

After an animal dies, many of its cells can remain alive for many hours, or in some cases even days, calling into question what kind of processes continue to occur in these cells [2]. Alexander Pozhitkov and colleagues set out to determine whether an animal’s genes were turned off abruptly after death, or whether they slowly faded like a flashlight running out of battery. Pozhitkov’s team examined most of the genome to examine which genes were turned on and off in zebrafish and in the brains and livers of mice for up to 4 days after their death. What they found was surprising - the team discovered that expression of a large group of the genes they looked at was actually elevated even 48 hours after death.

Some of these upregulated groups of genes appeared to indicate cells “gasping” for life after the organism had died around them. These groups included genes involved in processes such as the cell’s stress response, cell death, and the cell’s response to oxygen deprivation. However, other groups of upregulated genes were more unexpected. These groups included genes involved in development of embryos and genes associated with cancer.

Pozhitkov and his colleagues stressed that rather than being part of a larger survival strategy for cells, the upregulation of many of these genes that occurred after the death of mice and zebrafish may simply be a product of the cell no longer having the ability to control its cellular processes. Regardless, the findings will potentially shed light on the processes by which a cell controls its genes, and may have profound implications for our ability to better understand health issues associated with organs transplanted from a recently deceased person into a living patient. Additionally, the finding that certain genes are turned on and off at different times after death may help forensic scientists more accurately determine when a victim died.

In short, be on the lookout: Pozhitkov’s findings may soon be coming to a TV near you on Grey’s Anatomy or CSI.
 

- Jeff Maloy (@JeffreyMaloy)
Staff Writer, Signal to Noise Magazine
PhD Candidate, Microbiology

 

References:
[1] Pozhitkov A.E., Neme R., Domazet-Loso T., Leroux B.G., Soni S., Tautz D., Noble P.A. Thanatotranscriptome: genes actively expressed after organismal death. Preprint in BioRxiv. (2016). DOI: 10.1126/science.aaf5802

[2] Singh M., Ma X., Amoah E., Kannan G. In vitro culture of fibroblast-like cells from postmortem skin of Katahdin sheep stored at 4 °C for different time intervals. In Vitro Cell Dev Biol Anim. (2011). DOI: 10.1007/s11626-011-9395-
 

Calling a Microscopic Quorum: How Fungi Communicate

C. neoformans as single cells. Image credit: Gross L (2006) Iron Regulation and an Opportunistic AIDS-Related Fungal Infection. PLoS Biol 4(12): e427. doi:10.1371/journal.pbio.0040427.


Microbes find strength in numbers. Rarely alone, they live in communities and share resources by coordinating their biological processes. Just as governing bodies require a quorum, or a minimum number of people present, before deciding something on behalf of the entire group, many species of microbes must establish a quorum before coordinating their behavior. Microbes do this through quorum sensing, in which they release signaling molecules such as hormones or small proteins into the surrounding area and then sense the concentration of those signals. As more microbes enter the environment, the concentration of the signaling molecule will increase. Once the microbes sense that the concentration has met a certain threshold, they will initiate a particular biological process.


Microbes often use quorum sensing to determine when to release virulence factors, molecules that will help them overwhelm their target and establish an infection. They only want to spend energy making a virulence factor when there are other cells present because if too few microbes are present, they will not make enough virulence factors to successfully infect their target, and thus will have wasted energy. Quorum sensing systems have been very well characterized in bacteria but not as well in other microbes. In a recent study in the journal Cell Host & Microbe, Homer and colleagues identified and characterized a quorum sensing system in a eukaryotic microbe, the pathogenic fungus Cryptococcus neoformans, which is the most common cause of fungal meningitis [1]. They found that fungal cells with a mutation in the quorum sensing signaling molecule gene, qsp1, were less successful at infecting mice than C. neoformans cells with a fully functional quorum sensing signaling molecule. Through a series of experiments, they elucidated other components of the quorum sensing pathway and found that qsp1 functions inside the fungal cell to control virulence. Previous work identified a quorum sensing system in the pathogenic fungus Candida albicans, but the quorum sensing molecule discovered is produced by many different organisms [2]. Because the newly discovered quorum sensing system described here is specific to C. neoformans, it presents the unique opportunity to develop strategies to specifically disrupt the ability of C. neoformans to cause disease.


-Stephanie DeMarco (@sci_steph)
Staff Writer, Signal to Noise Magazine
PhD Candidate, Molecular Biology

References:

[1] Homer CM, Summers DK, Goranov AI, Clarke SC, Wiesner DL, Diedrich JK, Moresco JJ, Toffaletti D, Upadhya R, Caradonna I, Petnic S, Pessino V, Cuomo CA, Lodge JK, Perfect J, Yates JR 3rd, Nielsen K, Craik CS, Madhani HD. Intracellular Action of a Secreted Peptide Required for Fungal Virulence. Cell Host & Microbe. (2016). DOI: 10.1016/j.chom.2016.05.001.

[2] May RC. Custom-Made Quorum Sensing for a Eukaryote. Developmental Cell. (2016). DOI: 10.1016/j.devcel.2016.05.014.

The Discovery of Gravitational Radiation and Why It Matters

Gravitational wave signal detected by LIGO.
Image credit: LIGO, NSF, Aurore Simonnet (Sonoma State U.)

This Wednesday, the Laser Interferometer Gravitational Wave Observatory (LIGO) announced the second detection of gravitational radiation emanating from a merger of two black holes. This follows the initial discovery of gravitational radiation in February [1]. But why should any of that matter to you? We can't feel our bodies being squeezed by gravitational waves. The discovery of gravitational waves is important because it confirms that the laws of physics work the way we always thought they did. We've been talking about gravitational waves since the early 20th century, when Einstein first posited that the force of gravity might interact directly with space and time [2]. This concept of space and time interwoven as a “fabric” began with his theory of general relativity, and wasn't confirmed until February of 2016 (and again on Wednesday). The detection of gravitational waves doesn't just confirm Einstein's theory on space-time; it also confirms the existence of black hole mergers - extraordinarily energetic events in which two dead stars, each much larger than our Sun, enter a “death spiral” and eventually collide with one another. We're seeing the universe not only in electromagnetic radiation that propagates through space (light), but in gravitational radiation that propagates through the very fabric of space-time itself. It's like discovering a new color, or a new frequency of sound. This amazing technology ushers in a new era of astronomy, where we can now see the universe in an entirely different way.

Laura Haney (@LauraVican)
Signal to Noise Co-founder and COO
PhD, Physics and Astronomy

References:
[1] P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration), Observation of Gravitational Waves from a Binary Black Hole Merger. Phys. Rev. Lett. 116, 061102 (2016).

[2] Einstein, A.: Über Gravitationswellen. In: Sitzungsberichte der Königlich Preussischen Akademie der Wissenschaften Berlin (1918), 154–167. [English translation]
 


 

World of Concrete

World of Concrete

Like modern technology, concrete has become so ubiquitous, so important, that it perversely disappears altogether. The second most consumed substance on our planet after water, concrete defines our industrialized world. As with most every other aspect of industrialization, the rapid expansion of cement usage over the last century has come at a cost. Cement production accounts for 5% of the world’s total carbon dioxide (CO2) emissions. Gabe Falzone is a graduate student at UCLA working in the Laboratory for the Chemistry of Construction Materials run by Dr. Gaurav Sant. They’re working on ways to improve cement production, testing new techniques and chemical mixtures to make more durable, more sustainable concrete. 

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