Biology Archives - Princeton Insights

November 3, 2022November 3, 2022

Isolation Disorganizes Typical Social Interaction and Whole-Brain Genetic Expression in the Bumblebee

Review written by Adelaide Minerva (PNI, G4) and Rebekah Rashford (PNI, G5)

Throughout the COVID pandemic, many of us were faced with profound levels of social isolation which took a toll on both our mental and physical health. This has been especially detrimental for children, whose brains and social skills are still developing. Normally, social experience in early life plays a crucial role in guiding this development; but what happens when that guidance is no longer present? Disruptions to the early social environment have been seen to negatively impact other social species besides humans, such as mice, fish, and some insects. Studying how social isolation may disrupt the development of these highly social species can provide insight into the neural mechanisms underlying both typical and aberrant behavior at a level of detail not currently possible in human subjects. Taking advantage of one of these highly social species, Dr. Yan Wang and colleagues in the departments of Ecology & Evolutionary Biology and the Center for Biophysics at Princeton used bumblebees to measure the effects of early life social isolation on behavior, gene expression, and whole-brain neuroanatomy.

October 20, 2022October 20, 2022

Early life adversity can induce pathological avoidance behaviors in mice, but males with suppressed neurogenesis may step out of their comfort zones

Review written by Amy Ciceu (NEU, 2024)

Early life adversity, ranging from physical and emotional abuse, neglect, and violence, to poverty and unstable home environments, can have an enduring toll on child development. Some children who experience early life adversity may experience detrimental effects in the moment but develop into adults without pathological behavior. On the other hand, for certain children, the impacts of early life adversity increase the likelihood that they will develop neuropsychiatric disorders as adults. For instance, anxiety disorders are more prevalent amongst survivors of early life adversity compared to the general population. Although diverse in the symptoms they present and the treatments they require, anxiety disorders share one feature in common: heightened levels of anxiety. Normally, anxiety helps us steer clear of dangers. However, if ramped up into overdrive, excessive levels of anxiety can fuel a range of maladaptive behaviors.

October 13, 2022October 13, 2022

Socioeconomic status effects on human health have evolved with industrialization

Review written by Kimberly Sabsay (QCB, G3)

Socioeconomic status (SES), often simplified as absolute material wealth, is often linked to a variety of human health metrics. At a fundamental level, it makes sense that higher SES likely corresponds with access to better medical services, and in turn, better overall health. Studies have shown that, indeed, higher SES is associated with better human health, but the majority of this data comes from high-income countries (HICs). Despite the growing amount of scientific evidence for the apparent gradients in disease risk and survival explained by access to medical care and other health-related lifestyle factors, we cannot be certain that these trends are universal. Understanding the relationship between SES and health is crucial for policy design and to ensure we make economic decisions that do not negatively impact overall human health. Ultimately, the relationships between SES and health can be used to motivate positive change that benefits all of humanity.

July 5, 2022July 5, 2022

The Termite Wars: How tiny insect engineers shape the African savanna

Review written by Jarome Ali (EEB, G5)

Music by Three Music

On the savannas of Kenya, a battle has been waged for centuries. The landscape hints at how this battle has shaped the entire ecosystem, but it must be viewed from far above. From just a few meters above ground level, the telltale signs are still invisible. However, from the vantage point offered by drone photography or satellite imagery, a clear pattern emerges. Patches of vegetation are spotted across the savanna, in a regular hexagonal layout. This kind of order in the natural world fascinates biologists and begs for an explanation. Researchers at Princeton have been investigating how warring termite colonies (or insect colonies in general), and the underlying resource distribution can drive the emergence of order in the savanna landscape.

April 7, 2022April 7, 2022

Bacteria in the human microbiome can inactivate the antidiabetic drug acarbose

Review written by Abigail Stanton (MOL, G2)

Even in the microscopic world, survival of the fittest can make for relentless, and creative, competition. With a limited amount of resources to go around, some bacteria will play dirty to make sure they get their fair share. Actinoplanes sp. SE50/110, a bacterium that lives in the soil, has developed a strategy to fight off competitors: by producing a specialized sugar called acarbose, it can block proteins responsible for sugar uptake and metabolism in its microbial neighbors. This inhibits the growth of other bacteria, leaving more food for Actinoplanes to enjoy.

January 21, 2022January 21, 2022

AAV: Versatile Viral Hero or Neurotoxic Villain?

Review written by Amy Ciceu (NEU, 2024)

Adeno-associated viruses (AAVs) are some of the most widely used recombinant viral technologies—those that combine different genes to produce unique viral vectors, or tools that convey genetic material into cells—in modern neuroscience. Because they are incapable of being replicated within cells, recombinant AAVs are commonly used in neuroscience research as a means of expressing genes in specific cells. By expressing genes that heighten or dampen the function of certain cells, researchers are able to identify the functions of particular neural circuits.¹ This approach can provide scientists with insight into the mechanisms underlying neurobiological processes. To make such circuit-related discoveries, AAVs are typically injected into certain brain regions of animal subjects. After an incubation period, some AAVs encoding fluorescent tracers can induce cells to fluoresce under specialized microscopes, enabling scientists to visualize particular neural circuitry. Furthermore, AAVs have demonstrated clinical potential; for example, AAVs have been used to replenish certain proteins in the treatment of diseases like congenital blindness ^{2, 3} and spinal muscular atrophy.^{4, 5} AAV is also currently being investigated as a potential means of treating other brain disorders, including Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), and more.⁶

January 14, 2022January 14, 2022

What other species can teach us about how infants learn to speak

Review written by Sarah McFann (CBE, G6)

One thing that sets humans apart from our closest evolutionary relatives, Old World apes and monkeys, is that much of human brain development occurs outside the womb. This means that, relative to our evolutionary neighbors, humans are born altricial—a term describing animals that are born helpless and dependent upon parental care. Because our immature brains are presented with real-world stimuli as they develop, humans have the chance to be molded by external cues like language.

December 16, 2021December 16, 2021

Topology helps slime bacteria form fruiting bodies

Review written by Qiwei Yu (G1, QCB)

Nature never ceases to amaze us, particularly when it comes to how biological organisms develop sophisticated and diverse strategies to survive dynamic and oftentimes hostile environments. Myxobacteria (also known as “slime bacteria”), for example, have evolved a specialized life cycle to cope with the possibility of unreliable nutrient supply. While nutrient abundance enables the bacteria to grow and proliferate, nutrient scarcity can conversely trigger a transition to a more dormant state. In response to nutrient depletion, myxobacteria cells can aggregate into fruiting bodies, three-dimensional multicellular structures of diverse colors and shapes. A subset of the cells within the fruiting bodies develop into rounded myxospores with thick cell walls, waiting for a more favorable environment to resume growth. It is truly amazing how the behavior of a large number of cells can be coordinated to achieve the rapid and dynamic process of fruiting body formation.

November 18, 2021November 18, 2021

A Sea Squirt Story: What our squishy relatives teach us about the origins of the vertebrate brain

Review written by Jarome Ali (EEB, G4)

Clinging to the side of a marina you might find the usual suspects like mussels and barnacles, but lurking among these life forms is a less familiar one, a squishy invertebrate that looks like nothing more than a translucent tube. This creature is the sea squirt, Ciona instestinalis. Despite its unassuming appearance, Ciona could hold the key to understanding how the brain--the most complex structure in the universe--came to be. By investigating the evolutionary origin of the brain, we can uncover the roots of the remarkable variety of intelligence in the animal world and gain a deeper appreciation for the beautifully complex human brain. Princeton researchers are now studying the simple ‘brain’ of the sea squirt to begin to unravel this evolutionary story.

November 11, 2021November 11, 2021

Controlling microbial growth with a light switch

Review written by Olivia Duddy (MOL, G5)

Microbes are powerful tools in the biotechnology industry. Like microscopic factories, microbes are employed to manufacture a diversity of chemical compounds, such as industrial chemicals, food products, drugs, and other biotechnology molecules, on a large scale. Given the ease of genetic engineering in microbes like Escherichia coli and Saccharomyces cerevisiae, scientists and metabolic engineers alike tinker with their metabolic capacities, or even completely rewire them, to yield high concentrations of a specific product [1]. Metabolic engineers aim to maximize the efficiency of these biosynthetic processes. High efficiency, in turn, delivers biomolecules that are more readily available and at a lower cost. Metabolic engineering applications also can be more sustainable or environmentally friendly than traditional chemical synthesis approaches [1,2]. Recently, a team of researchers in the Avalos lab, led by former Ph.D. candidate Makoto Lalwani (now postdoctoral researcher at the Wyss Institute), added an additional layer of genetic engineering to this process: They are using light as a strategy to advance biomolecule production [3].