Functional organization of hypothalamus and central autonomic networks.
My research interests fall into two basic categories. A long-standing focus of the laboratory is definition of the functional organization of neural circuits involved in the control of behavioral state and autonomic function. The primary objective of these studies is to define the synaptic organization and chemical phenotype of the central networks that mediate these essential regulatory functions. Characterization of the plasticity and developmental assembly of these circuits is a related component of these analyses. The second focus of the laboratory is the development of tools for transneuronal tracing of neural circuits. This effort, which is fundamental to the goals of our investigation of neural circuitry, incorporates a mechanistic approach. It is supported by the National Center for Neuroanatomy with Neurotropic Viruses, which I co-direct with Dr. Peter Strick.
Current studies focus upon circuitry through which the brain stem, hypothalamus and limbic forebrain control autonomic function. Toward this end, we use neurotropic viruses to define the neural circuits that modulate sympathetic and parasympathetic components of the autonomic nervous system. In our most recent studies we are developing lentivirus vectors to to restrict viral replication to phenotypically defined neurons. We have shown that restricted transgene expression can be achieved in catecholamine neurons through the use of a synthetic dopamine-beta-hydroxlyase promoter. In developing this vector we demonstrated that expression of a GFP reporter gene under the control of this promoter labels the entire somatodendritic and axonal compartments of catecholamine neurons. We have exploited this novel technology to define the efferent projections of brainstem catecholamine neurons involved in cardiovascular regulation and are applying it for anterograde tracing of projection fields of other catecholamine neurons.
The collective intent of my research program is to pursue an integrated experimental plan that develops knowledge of the mechanisms of viral invasiveness and then exploits that knowledge for transneuronal analysis of the functional organization of neuronal circuits.
Card, J.P., Swanson, L.W. and Moore, R.Y.. Functional Organization of the Hypothalamus. In: Fundamental Neuroscience. (M.J. Zigmond, F.E. Bloom, S.C. Landis, J.L. Roberts, L.R. Squire, eds.), Academic Press, 2008.
Card, J.P., Sved, J.C., Craig, B., Raizada, M., Vazquez, J. and Sved, A.F. Efferent projections of rat rostroventrolateral medulla C1 catecholamine neurons: Implications for the central control of cardiovascular regulation. Journal of Comparative Neurology 499:840-859, 2006.
Card, J.P., Levitt, P., Gluhovsky, M. and Rinaman, L. Early experience modifies the postnatal assembly of autonomic emotional motor circuits in rats. Journal of Neuroscience 25:9102-9111, 2005
Card, J.P., Santone, D.J., Gluhovsky, M.Y. and Adelson, P.D. Plastic reorganization of hippocampal circuitry in experimental traumatic brain injury in the immature rat. Journal of Neurotrauma 22:989-1002, 2005.
Aston-Jones, G., Zhu, Y. and Card, J.P. Numerous GABAergic Afferents to Locus Coeruleus in the Pericoerulear Dendritic Zone: Possible Interneuronal Pool. Journal of Neuroscience 24:2313-2321, 2004.
Rinaman L., Levitt, P. and Card, J.P. Progressive postnatal assembly of limbic-autonomic circuits revealed by central transneuronal transport of pseudorabies virus. Journal of Neuroscience 20:2731-2741, 2000.