Prof. Daniel Blackburn (LSC 247)
Biology - Neuroscience
Functional Morphology & Reproduction of Reptiles My research concentrates on the structure, function, and evolution of reproductive specializations in reptiles, particularly features associated with viviparity (live-bearing reproduction) and oviparity (egg- laying reproduction). This work draws heavily on microscopic anatomy, and students interested in working with me ideally should gain experience with electron microscopy before their senior year by taking the half semester course Biology 210 (Scanning EM) and/ or Biology 220 (Transmission EM) before their senior year. These courses and our excellent EM facilities in the LSC and McCook offer wonderful opportunities for Trinity students to learn techniques of immense value to biologists. I sometimes have options for students who wish to focus their attention at the level of light microscopy. Research of several of my recent students has resulted in collaborative research papers, as well as presentations at scientific meetings.
Two major areas of research activity in 'the Blackburn lab' are:
1) Placental morphology and evolution of live- bearing reptiles: In viviparous lizards and snakes, embryos develop inside the pregnant female, and are sustained by means of placental organs. My main research interest is in understanding the structure, function, and evolution of these placentas. Our current work is focusing on how anatomical characteristics of the placental membranes of viviparous snakes and lizards enhance provision of oxygen, water, and nutrients to the fetus during gestation. This work involves examination of the cytology and development of the uterus and placental membranes, using light and electron microscopy.
2) Development and evolution of fetal membranes in oviparous lizards and snakes: During development, vertebrate eggs are sustained by cellular structures that provide for the respiratory and nutritional needs of the developing embryos. These structures contribute to the placentas of viviparous species. In reptiles and birds, very little is known about the structural composition of these membranes, and how they develop and function. Our current investigations of reproduction in snakes and lizards use light and electron microscopy to study the development and cytology of these membranes. Resultant data offer insight into important aspects of egg function and evolution. Future work will focus on eggshell anatomy (as seen through electron microscopy) and mechanisms of calcium and water uptake.
Prof. Harry Blaise
Engineering - Neuroscience
Prof. Blaise’s research goals are to develop models and tools to advance the study of the biomedical sciences. He currently conducts research at the intersection of biomedical engineering and neuroscience. He has studied the neurophysiology of learning and memory consolidation using his freely behaving mouse and rat model of long-term potentiation (LTP) and depression (LTD)—two candidate mechanisms accounting for much of the information processing performed by the brain. Dr. Blaise has also investigated the impact of prenatal protein malnutrition and neonatal stress on brain circuits involved in learning. More recently, Dr. Blaise has been conducting research whose ultimate aims are to help better understand the linkages between emotionality and memory. For instance, does one’s emotional state alter the ways in which concurrent events and experiences are remembered? Further, stress is known to be mostly harmful to the brain (e.g., as in post-traumatic stress disorders); but are there situations in which stress might be beneficial to brain function? Prof. Blaise’s research aims are to answer some of these difficult questions.
Prof. Elizabeth Casserly
In my research, I explore the mechanisms of real-time language use, particularly the means by which we achieve and control everyday speech perception and speech production. Both of these seemingly-effortless processes respond flexibly to a wide range of environmental and conversational demands – altering, for example, the amount of inference operating in speech perception and the acoustic attributes of speech production in the presence of background noise. How do we learn these responses to changes in the environment? What are the boundaries of control and successful communication? What is the relationship between perception and production in speech, particularly in challenging contexts such as communication in a second language, with varying degrees of hearing impairment, or adverse environmental conditions?
My lab uses classic behavioral speech perception experiments, acoustic and articulatory analysis of speech production, and manipulation of the context occurring between talkers and listeners to attempt to answer these questions. The issues they address touch on a wide range of topics, from our understanding of basic perceptual and motor processes, to the relationship between form and purpose in language, to how atypical communication circumstances in schools or clinical settings can be addressed most effectively.
Prof. William H. Church
Chemistry - Neuroscience
1. Identification of Neurochemical Causes of Nigrostriatal Cell Death
Oxidative stress, with the subsequent generation of oxygen free-radicals, is thought to play a role in the neurodegenerative processes observed in Parkinson's disease. The neuronal sources of these radicals and the endogenous anti-oxidant mechanisms present in brain to control oxidative stress have recently been the focus of intensive investigations. While it has been established that an environment conducive to oxidative stress (deficiencies in anti-oxidant mechanisms and increased levels of iron) exists in the substantia nigra of parkinsonian patients, a fundamental understanding of the chemical reactions responsible for the cell death associated with Parkinson's disease is lacking. The research conducted in my laboratory is designed to provide insight into these reactions. Currently experiments focus on identifying factors associated with susceptability to various neurotoxins(Church and Rappolt, Exp. Brain Res., 127 (1999) 147 -150). Ongoing projects regarding this research area include the manipulation of uric acid levels in a cell culture model, the effect of anti-oxidant deficiencies on neurotoxin-induced apoptosis (in cell culture),and the role of NMDA receptor expression on dopamine cell death (using cell cultures). Techniques utilized in this research include HPLC, spectroscopy, immunochemistry, cell culture, uptake of radioactive isotopes, and histology.
2. Development of Analytical Methods to Monitor Changes in Anti-oxidant Levels
Associated with the projects described above, projects involving utilizing analytical methodology to quantitate changes in the neurochemical milieu and intracellular content of cells exposed to various neurotoxins are ongoing. Techniques utilized in this research include HPLC, spectroscopy, electrochemistry, and solid-phase extraction.
Prof. Kent Dunlap
Biology - Neuroscience
Electrocommunication & Physiology of Electric Fish
I examine the influence of social interaction on the brain structure and communication of electric fish. South American weakly electric fish are nocturnally active and live in muddy waters of the Amazon River basin. They use their electric discharges both for locating objects in the environment and for communicating with each other. These fish have a remarkable ability to generate new cells in the brain during adulthood, at about 100 times the rate of adult mammals. Research by Trinity students showed that this production of new cells is influenced by social interaction. Pairing fish with another fish increases the production of cells in a brain region that controls electrocommunication behavior.
In our present research, we address three main questions: 1) What specific component of social interaction is effective in stimulating changes in brain cell production? 2) Do the new cells that are produced contribute to changes in electrocommunication behavior? 3) How do these newborn cells differentiate into mature cells? This research involves examining the expression of certain molecules in the brain using antibodies and florescent microscopy. In a separate project, students examine electrocommunication behavior between different species of electric fish and conduct experiments to determine the sensory pathways involved in this interspecific electrocommunication. This research involves observing fish as they interact and stimulating fish with artificial electrocommunication signals.
Prof. Hebe Guardiola-Diaz
Biology - Neuroscience
Cell Signaling Pathways in Oligodendrocytes
Oligodendrocytes are extraordinary cells that form the myelin sheath that increases the speed of communication between neurons in the brain. In order to produce myelin, oligodendrocytes must make great amounts of lipids and proteins in their endoplasmic reticulum (ER). Therefore, a healthy endoplasmic reticulum is essential for myelin formation and maintenance. Myelin diseases display accumulation of unfolded proteins that may arise, in part, from failure to adapt to ER stress. I am investigating the interaction between ER function and signaling pathways known to be active in oligodendrocytes. I am especially interested in the signaling protein mTOR, which controls protein synthesis in response to hormones, nutrients and energy levels in the cell. These studies will further our understanding of the endogenous mechanisms that make oligodendrocytes resilient and therefore able to establish a robust myelin sheath in dynamic association with its axon.
Prof. Dan Lloyd
Philosophy - Neuroscience
I examine aspects of the neural basis of human consciousness. This principally involves the reinterpretation of functional MRI brain scanning data, data that are archived in various research centers and freely available. One main theme of this work is the pervasive human experience of time, which underlies all consciousness. Since temporality always accompanies awareness, it cannot easily be factored out as an experimental variable. Nonetheless the “flow” of time may be a parameter that varies in different tasks and contexts. Looking for evidence of this variable flow is ongoing. All of the analysis is carried on using the powerful computing environment, Matlab. Often students coordinate research under my direction with research opportunities at the Olin Neuropsychiatric Research Center at the Institute of Living. The course “Minds and Brains” (Phil 374 and its lab, Phil 371), provides a philosophical context for understanding functional brain imaging.
Prof. William M. Mace
Psychology - Neuroscience
I. Studies in Vision Science. Students interested in vision research can work in my lab with animated computer displays designed to find out (1) “Biological Motion” perception – what can be seen from just a few points of moving lights? The range of what has been discovered to date is extensive – not only can a person be seen in such displays, but the person’s age level, gender, intention, and strength. Moreover, interactions between people and environmental features also can be specified. Understanding how this is possible is a great challenge. (2) the conditions for seeing moving shapes as rigid or not, or (3) the conditions for combining patterns seen by two eyes into a single pattern in depth. Research in this area is like studying computer graphics, TV and movie cartoons, and neuroscience.
II. Studies in Movement Science. Students interested in understanding the control of human movement can study (1) the coordination of rhythmic patterns, in rowing and in music, and (2) the perception of tools in sports. For example, what can an athlete feel about a lacrosse stick, hockey stick, ping pong paddle, baseball bat, squash racquet, or tennis racquet without looking?
Tools used in sports extend the capacity of the body in ways that are poorly understood and leave room for fascinating research. You hold a tool with your hands, and feel only patterns of pressure on the hands, arms, and body, but you feel a unitary stick or racquet that has length beyond your hand.
Prof. Susan Masino
Psychology - Neuroscience
The main topic of my research is the neuromodulator adenosine. Adenosine is the core molecule of the cell energy molecule ATP, and it also participates in controlling brain activity. Adenosine helps protect neurons during pathological conditions such as stroke, and is known to stop epileptic seizures, but the ongoing role and regulation of adenosine is less well understood. By combining techniques such as imaging, electrophysiology, and behavior we are revealing more of the underlying cellular mechanisms which regulate adenosine and recording their effects on brain activity. With its dual role in cell energy and brain activity, we are particularly interested in the relationship between metabolism and brain activity.
A major current focus of the laboratory is the relationship between ketogenic diet therapy and the actions of adenosine in the nervous system. A ketogenic diet is high in fat and low in carbohydrates and a highly successful metabolic therapy for reducing epileptic seizures. A ketogenic diet is effective even in cases where all drug treatments have failed, and it is particularly effective in pediatric epilepsy. Adenosine is similarly effective at reducing all types of seizures. We are currently testing this hypothesis and predictions of this hypothesis. This research may yield new insight into the mechanisms underlying the success of ketogenic diet therapy, as well as new insight into how to regulate adenosine.
Prof. Sarah Raskin
Psychology - Neuroscience
My research primarily involves examining behavioral methods to facilitate changes in human brain structure following damage to the brain. It has been documented that repeating particular tasks (such as simple motor movements) causes increases in the number of brain cells involved in coordinating that task. Early studies using positron emission tomography suggest that indeed, repetitive practice does cause a greater area of the brain to be used for the function that is being practiced. Our research is an attempt to determine which types of practice are most effective and whether they can be effectively used to help people who have had brain damage. We measure effects of treatment using behavioral measures, measures of generalization to daily life and electrophysiological measures (EEG).
People with brain injury experience several types of cognitive deficits. Often they have trouble paying attention. One particular function that is often lost is memory. This is a complex function that involves large systems in the brain. As such, virtually no treatments for memory loss have been effective. More specifically, the type of memory that people with brain damage find most troubling is prospective memory. This is the ability to remember to do things in the future (for example, remember to buy milk at the store on your way home). We are currently working on creating measures that more effectively test and treat prospective memory.
Prof. Chris Swart
Biology - Neuroscience
As laboratory coordinator my main area of interest currently is developing lab modules for use in several neuroscience courses here at Trinity. My goal is to provide students with artificial and animal models, computer software, and cognitive exercises that demonstrate the concepts discussed in neuroscience lecture courses. These laboratory exercises span the range from anatomy to behavior, electrophysiology, chemistry, psychology, and cognitive science. I am very interested in allowing students to experiment with novel animals, models, or apparatus that will foster the skills necessary to promote the pursuit of original thesis research or post-graduate study.
In addition to my main focus on developing new neuroscience labs I am currently involved in two research projects. I have started a series of experiments aimed at describing the structure and function of the Cerebral Ganglion of the freshwater snail, Cipangopaludina chinensis using a variety of techniques including tract tracing, histology, electron microscopy, and electrophysiology. My second area of research interest is in coordination with Prof. Masino’s research on adenosine signaling. I have been using electrophysiology and electrochemistry to understand the relationship between temperature and adenosine regulation in the mammalian hippocampus.