Posts byKristina

Zebras in California! The B. Bryan Preserve

“Just pull your car up to where the zebras are, and I’ll let you in through the gate” said Judy in her thick Mississippi accent. Initially, I assumed I had misheard her, but I quickly disproved this thought after I spotted a herd of zebras roaming freely in the distance. My jaw dropped, and I turned to my friends Cam and Christina just in time to catch the “Surprise, Kristina!” look on their faces. My friends had surprised me with a weekend at B.Bryan Preserve, a preserve started by Judy and Dr. Frank Mello. It is located in Point Arena, California (a small town with a population of >500) and is dedicated to breeding and preserving the bloodlines of endangered African hoof stocks, including the now rare Grévy’s and Mountain zebras.

At first, it was hard for me to believe most zebra species are classified as being at high risk for extinction. But the math begins to make sense when I start thinking about the drought in Africa, the increase in other livestock that ultimately degrade the zebra’s food supply, and the emerging tick-borne disease covered in Science Daily a few weeks back.

A beachhead in the war on Alzheimer’s disease

Hello there, BSR readers; it’s good to be back. It’s been a while since I’ve posted anything—that’s because I’ve recently made some pretty big life transitions. After graduating from the Psychology Department last May, I was lucky enough to land a job at Stanford Research International. While I miss being able to protest between classes, and study in trees, and though I often find myself overwhelmed with Silicon Valley preppies, it has been a wonderful experience thus far. I am currently participating in wonderful and novel Alzheimer’s research in Joseph Rogers’s laboratory of the neurobiology of aging. I want to share with you the science that has motivated me.

Before we talk cures, I need to first explain the disease itself. Alzheimer’s disease (AD) is a neurodegenerative disorder that is the sixth-leading cause of death in the United Sates and affects an estimated 5.4 million Americans. AD most often occurs later in life. It is characterized by progressive deterioration of brain function, and ultimately leads to death. On a cellular level, AD is associated with loss of neurons and synaptic connections within the cerebral cortex. AD patients also experience atrophy of many brain regions including the amygdala (which is dedicated to management of basic emotions), the frontal lobe (the part of the brain responsible for logic and behavior regulation), and the hippocampus (which aids memory).

Regardless of the large body of research that has been dedicated to AD, and despite the well-understood neuropathology of this disease, the root cause of this disorder remains obscure. The most widely accepted hypothesis for the cause of AD is the amyloid hypothesis, which postulates that the primary cause stems from deposits of the peptide amyloid beta (Abeta) within the brain. Abeta is a multifunctional protein that facilitates many processes (including kinase activation and regulation of cholesterol transport). However, Abeta is highly elevated in AD patients, causing the protein to form aggregates (called plaques) within the brain. In large enough amounts, these plaques initiate the damage to neurons.

Machine learning plumbs the depths of the psychedelic experience

Huichol yarn painting, inspired by peyote, the sacramental cactus containing the psychedelic chemical mescaline.

Linguistics, the study of human language, is derived from “lingua”, the Latin word for tongue. While the literal translation of this word may imply that the organs of sound production (tongue, lips, gottis) are the most important instruments for language, language is a mental process and, therefore, the most fundamental organ of this phenomenon is the brain.

In his text Peri Hermeneias (‘On Interpretation’), Aristotle argues that “spoken words are the symbols of mental experience,” which suggests that the relationship between language and the mind has been considered for thousands of years. Linguistics has greatly advanced since the days of the early Greek philosophers and is now prevalently integrated with the physical and social sciences as subfield called cognitive linguistics. In this field, the brain is applied to understand language, and language is applied to understand the brain.

Over the past several years, Jeremy Coyle (graduate of UC Berkeley’s Cognitive Science Program and currently a graduate student in UCB’s Biostatistics Group), Dr. David Presti (UCB Department of Molecular and Cell Biology and Program in Cognitive Science), and Dr. Matthew Baggott (graduate of UCB’s Neuroscience doctoral program and currently at the University of Chicago’s Department of Psychiatry and Behavioral Neuroscience) collaborated to study language as a means to understand the effect of psychedelic substances on the mind, and on brain physiology. Psychedelics alter perception, consciousness, thoughts, emotions, mood, and behavior by changing brain chemistry and function. Because of the profound changes that are induced by this class of chemicals, psychedelics may be optimal tools to unveil the specific mechanisms that connect brain physiology to complex mental phenomena (an unanswered relationship known as the “mind-body problem”). Despite the insight to the mind-body problem that psychedelic drugs could provide, the use of these chemicals in neuroscience is scarce in comparison to other tools that are utilized. The paucity in psychedelic research is attributed to the lack of acceptance within the scientific and nonscientific community, and the lack of a good human model.

Drumming with SAVE THE FROGS!

The historical Bay Area is notorious for many things, wine, activism, and music–to name a few. Most Berkleyans will agree that this area is practically overrun with protesters, painters, and artists. While The Black Keys might have rocked Outside Lands last year, the best performance around is Drumming for the Frogs, a group composed of scientist, educators, and musicians, who drum to save endangered amphibians.

Drumming for the Frogs is a movement that is associated with an organization called SAVE THE FROGS!, the first and only public charity that is dedicated to raising the awareness and education of environmental conservation. SAVE THE FROGS! aims to acquaint society with an appreciation for amphibians and develop a public interest in wildlife.

Was Darwin right after all? Gene Hunt gives new life to an old take on evolution

Joining us on April 17th for the Integrative Biology seminar was Gene Hunt, a curator at the Smithsonian Institute, whose parents must have known when they named him what occupation he would be getting into. Specifically, he “hunts” changes in the “gene” pool of Ostracoda, a bivalved crustacean that, on average, has a length that is smaller than the thickness of a dime.  The genus Hunt investigates, Poseidonamicus, is found at a water depth below one kilometer in every part of the world except the Arctic and the Mediterranean and has a fossil record worth bragging about. Additionally, the fossils carry several distinct morphological traits that can be compared over evolutionary time. These factors enable Poseidonamicus to provide immeasurable insight on how evolutionary changes occur.

Charles Darwin’s monumental publication, On the Origin of the Species, provoked great criticism because it proposed a linear evolution of change not supported by fossil records at the time. In 1859, there were only 51 dinosaur fossils recorded in scientific literature, leading Darwin to argue that the intrinsic lack of data made it difficult to draw any tangible conclusions about how species change over time. The worldwide fossil collection has taken an exponential increase since the time of Darwin, finally allowing paleontologists to observe and measure morphological changes in a species over time.

In-depth perception: notes from the lab of Michael Silver

What do you read below?

Most people who look at the above figure will perceive the symbols as “THE CAT”, when in reality the middle character in each word can be perceived as either an “H” or an “A”. This effect is an example of top-down processing, a mode of brain function in which previous knowledge and contextual information drive our cognition of the world. Bottom-up processing, on the other hand, occurs when information from the physical stimulus, rather than the general context, is used to process sensory input. “Perception” is an integration of both top-down and bottom-up processing.

Recently, scientists discovered that the neurotransmitter acetylcholine modulates brain activity by shifting cortical processing towards a more bottom-up mode. Though the mechanisms remain somewhat obscure, it is known that acetylcholine suppresses intracortical connections that connect neurons within a cortical area to each other, thereby increasing the focus on physical properties of the stimulus. Because the balance between bottom-up and top-down processing is so important, damage to cholinergic cells can have profound consequences on behavior and cognition.

Carbon Flux Explorers take to the seas

The next time you’re out sailing the Seven Seas, keep an eye out for something small and red floating atop the water. It’s likely a Carbon Flux Explorer – an important scientific instrument and the brainchild of UC Berkeley professor Jim Bishop. My sidekick E.J, a researcher in Bishop’s lab, recently told me the fascinating story of how he had been involved in the launching of one.

While I may not be the most proficient oceanographer out there, with the help of E.J’s clear teaching style, I learned that Carbon Flux Explorers are robotic devices that measure an array of important oceanic properties. These measurements help elucidate how the rising CO2 levels in our atmosphere will affect the stability of carbon flow in the ocean.  The ocean experiences rapid temporal changes in carbon due to biological transportation of carbon from the surface of the ocean (where photosynthesis occurs) to the deep ocean interior. This involves phytoplankton, which absorb CO2 from the atmosphere, and the excretion and sinking of CO2 by the animals that feed off of the phytoplankton. The stability of this intricate cycle is sensitive to global changes, and until the invention of Carbon Explorers we had no effective way of observing the arms, feet, and backbone that make up the ocean body’s cycle.