Spring 2004 Seminar Series in Neuroscience

Wednesday Jan 28, Noon-1 pm

Mark Mattson, Laboratory of Neurosciences & Gerontology Research Center, National Institute on Aging

"Neurohormesis: Implications for Aging and Neurodegenerative Disorders"

Co-Sponsored by the Institute for Behavioral Genetics & the Center for Neuroscience

Special Location: CU Boulder-EAST CAMPUS: Institute for Behavioral Genetics Building Room 120 (this is the building closest to Boulder Creek -- immediately East of 30th St and North of Boulder Creek. Entrance is on the East side)

Abstract: Most types of cells, including neurons, respond to a mild stress such as high temperature or energy deprivation by activating signaling pathways that induce the expression of various stress resistance proteins (heat-shock proteins and growth factors). When neurons are subjected to mild oxidative or metabolic stress they become more resistant to being damaged and killed in experimental models of neurodegenerative disorders such as stroke, Parkinson's and Alzheimer's diseases. We have found that a similar "neurohormesis" response can be induced by dietary restriction (intermittent fasting) in mice and rats, thereby increasing the resistance of neurons to dysfunction and degeneration in models of neurodegenerative disorders. Dietary restriction also stimulates neurogenesis (the production of new neurons from stem cells) and enhances synaptic plasticity (learning and memory). The beneficial effects of dietary restriction on the brain are mediated, in part, by upregulation of brain-derived neurotrophic factor (BDNF) and the protein chaperones HSP-70 and GRP-78. These findings have important implications for preventing and treating neurodegenerative disorders by dietary modifications.

Tuesday Feb 3, 4-5 pm Jerry Rudy, Dept of Psychology, CU-Boulder

TITLE: The Hippocampus, Conjunctive Representations, and Contextual Fear Conditioning

Abstract: Contextual fear conditioning is an important behavioral paradigm for studying the neurobiology of learning and memory and the mnemonic function of the hippocampus. We suggest that research in this domain can profit by a better theoretical understanding of the processes that contribute to this phenomenon. To facilitate this understanding, we describe a theory which assumes that the physical elements of a conditioning context can be represented in the brain as either (a) a set of independent features or (b) the features can be bound into a conjunctive representation by the hippocampus which supports pattern completion. Conditioning produced by shocking a rat in a particular context, in principle, can be produced by strengthening connections between the feature representations and/or the conjunctive representation and basolateral region of the amygdala. We illustrate how this theory clarifies some of the complexities associated with the existing literature and how it can be used to guide future empirical work. We also argue that the mechanisms (conjunctive representations and pattern completion) that mediate the contribution the hippocampus makes to contextual fear conditioning are the same ones that enable the hippocampus to support declarative memory in humans.
Tuesday Feb 17, 4-5 pm

Randy O'Reilly, Dept of Psychology & Institute for Cognitive Sciences, CU-Boulder

TITLE: "Computational Principles of Learning in the Neocortex and Hippocampus: From Conditioned Fear to Logical Inference"

Abstract: I present a computational approach toward understanding the different contributions of the neocortex and hippocampus in learning and memory, and models of several key phenomena in animal learning. The approach is based on a set of principles derived from converging biological, psychological, and computational constraints. The most central principles are that the neocortex employs a slow learning rate and overlapping distributed representations to extract the general statistical structure of the environment, while the hippocampus learns rapidly using separated representations to encode the details of specific events while suffering minimal interference. Additional principles concern the nature of learning (error-driven and Hebbian), and recall of information via pattern completion. Models incorporating these principles simulate a wide range of data in conditioning, habituation, contextual learning, recognition memory, recall, and transitive inference. I will present a few key findings and predictions from these models, together with recent behavioral tests of these predictions.

Tuesday March 2, 4-5 pm

Kenneth Wright, Dept of Integrative Physiology, CU-Boulder

TITLE: Sleep, Homeostatic and Circadian Regulation of Human Performance in the 24-hr Society

Abstract: The internal circadian clock and sleep-wake homeostasis regulate and organize human brain function, physiology and behavior so that wakefulness and its associated functions are optimal during the day and that sleep and its related functions are optimal at night. This talk will discuss the concepts of adequate sleep, circadian timing and how these two fundamental central nervous system properties interact to regulate human performance. Implications of the research findings will be discussed in the context of work, performance, accidents, and learning in today's 24 hour society.

Tuesday Mar 16, 4-5 pm Jack Kinnamon, Dept of Biological Sciences, University of Denver


Tuesday April 6, 4-5 pm Philip Haydon, Dept of Neuroscience, Univ Pennsylvania

TITLE: Glia: Listening and Talking to the Synapse

Abstract: Glial cells are emerging from the background to become more prominent in our thinking about integration in the nervous system. Given that glial cells associated with synapses integrate neuronal inputs and can release transmitters that modulate synaptic activity, it is time to rethink our understanding of the wiring diagram of the nervous system. It is no longer appropriate to consider solely neuron-neuron connections; we also need to develop a view of the intricate web of active connections among glial cells, and between glia and neurons. Without such a view, it might be impossible to decode the language of the brain.
Tuesday April 20, 4-5 pm

Drake Duane, Arizona Dystonia Institute, Scottsdale, AZ