The developing embryo is made up of special cells called stem cells. Unlike most cells, stem cells have the unique ability to transform into specialized adult cells, such as those that make up our heart or the neurons in our brain. In the last five years, scientists have designed a method to go backwards; now the specialized adult cells can be turned into embryonic stem cells. However, a lot of questions remain unanswered. For instance, scientists still do not completely understand what triggers stem cells to transform into different cell types. Or what process keeps stem cells from changing in the first place.
Our guest, Dr. Barbara Panning, a professor in the department of biochemistry at UCSF, is in the process of answering this question. Using a process called RNA interference, her lab turns off specific genes one by one to see how embryonic stem cells are affected. Her research has potentially important implications for diseases like breast cancer.
Even exercise can damage your muscles. Muscle cells then need to regenerate to keep you healthy. This month, we talk with Christine Snyder, a graduate student in the lab of Frank Naya at Boston University who studies how muscle regrowth is regulated.
Her work in the Naya lab focuses on a transcription factor (a protein that interacts with the DNA to affect gene transcription) known as Mef2A. Her lab studies mice that lack this transcription factor and show specific deficits in muscle development. She also explains how a technique called RNA interference can be used to silence certain genes to determine their function in cell cultures or animal models. Christine’s work has important implications for manipulating muscle regeneration after disease or injury.
Pain helps us avoid potentially harmful situations and is necessary for survival. While most of us only experience acute pain while the painful stimulus is present, some people unfortunately suffer from constant pain that persists long after the stimulus is removed. Our guest this week, Allan Basbaum, a professor and chair of the Department of Anatomy at UCSF, is interested in chronic pain and its cause.
During our interview, Dr. Basbaum explains how pain is in the brain; the pain that one person feels can be more (or less) intense than another person’s perception even if the stimulus is identical. His lab investigates how chronic pain can occur by changes in the nervous system and the role of epigenetics (the interactions between your DNA and all other non-DNA elements). They are also interested in transplanting inhibitory precursor cells (cells that develop and eventually inhibit the activity of surrounding neurons) to help the spinal cord suppress pain signals. His findings could eventually lead to effective therapies to treat this debilitating disease.
The brain’s capacity to remember experiences to guide future decisions is an essential and fascinating ability. Our guest this month Loren Frank, an associate professor in the Keck Center for Integrative Neuroscience at UCSF, is working to understand this process.
Dr. Frank studies how the hippocampus, a brain structure required for the formation of memories, mediates spatial learning in rats. Within the hippocampus exist place cells: neurons that are activated whenever an animal is in a specific location in its environment. His lab records the neuronal activity of place cells during formation and “replay” of memories while rats explore their environment. Disrupting the “replay” prevents the long term formation of memory. Later in our interview, Dr. Frank discusses his initial interest in astrophysics and how he became interested in a career in neuroscience.
David Kleinfeld is a professor in the Department of Physics at the University of California, San Diego. In this month’s episode, Dr. Kleinfeld talks about the different, important questions his lab is addressing.
One part of his lab is trying to understand how the brain uses sensory input to process information about the environment. The lab uses the vibrissa (whisker) system in rats and mice to understand how they sense and navigate the world. Next, Dr. Kleinfeld discusses how changes in blood flow in the brain can be used to visualize electrical activity evoked by different stimuli. The tools his lab let them see blood flow at the level of a single blood vessel. Using these optical techniques, they can map every blood vessel and brain cell within sensory cortex. Creating a complicated “road map” of the brain can eventually be used to help interpret results from imaging techniques such as fMRI used in humans.
Auditory and visual cues are crucial for perceiving the environment. Within the brain, both auditory stimuli and visual stimuli are organized topographically. In the visual system this means that neighboring spots on the retina project to neighboring spots in the brain. Likewise, areas along the basilar membrane in the cochlea which are sensitive to increasing frequencies of sound maintain this arrangement in the areas of the brain to which they project.
Our guest this week is Jason Triplett, a postdoctoral researcher at the University of California, Santa Cruz. He is interested in understanding the molecular and genetic mechanisms that guide the formation of these spatial maps. Jason will discuss how waves of neuronal activity that take place during development (before the eyes are even opened) are used by the brain to establish these complicated maps. Finally, we will hear briefly about the experiences that led him toward a career in science.
Our guest this month is Andrew Huberman, an assistant professor in the department of neurobiology at UCSD. Dr Huberman is interested in a classic question in development—how do the eyes connect to the brain? Cells known as retinal ganglia cells (RGCs) receive information from photoreceptors in the retina and carry this information to the brain. Connections from the left eye and right eye connect to the same part of the brain early on, but sort into two groups during maturation. Furthermore, different subtypes of RGCs respond to color, motion, and brightness and these subtypes target separate, designated regions of the brain. Andrew and his lab are exploring the mechanisms that guide the separation of different subtypes of RGCs during development. At the end of our interview, he explains the role of electrical activity and different genes in guiding the migration of these cells during development as well as how a course on the biology of behavior inspired him to pursue a career in neuroscience.
Your brain is composed of a tremendous number of neurons that make very specific connections with each other. The formation of this extremely complex circuit requires that each neuron find its appropriate target. Dr. David Van Vactor and his lab at Harvard University study the cellular machinery that help motor neurons navigate and find their correct partners, muscles, during development. They are also investigating how the neuromuscular junction is formed and maintained once the neuron reaches its destined target. At the end of our talk with David, he discusses the experiences in elementary school and college that led him to a career in science.
In this week’s episode we talk to Dr. Ulrike Heberlein, a professor in the department of anatomy at UCSF and baseball aficionado. This year, she was elected to the National Academy of Sciences, one of the highest honors that can be awarded to an American scientist.
Dr. Heberlein is interested in the genes that underlie alcoholism and drug addiction and uses a seemingly unusual animal model to study it—the fruit fly. Using this model, her lab has identified a gene dubbed happyhour that, when mutated, can reduce an organism’s response to alcohol. She discusses how her lab uses the findings in the fly to guide further experiments in rodents and how these discoveries may soon lead to developing treatments for alcohol addicts.
Our guest this week is Michael Shadlen, a professor at Washington University, HHMI investigator, and avid jazz guitarist.
Some neurons in our brain help us sense our environment while others help us move our body parts. Dr. Shadlen is interested in the neurons that link sensory information with behavior—the neurons that help us think and decide. He is also interested in how our brain can keep track of time. Learn how Michael and his lab record from the brains of monkeys to study these processes.
