The focus of my research program is to determine the activation and plasticity of neurons, especially corticotropin releasing factor (CRF)-containing neurons, in response to a brain insult (i.e., stress, transient global forebrain ischemia, seizure). Current studies address 1) the effect of transient global ischemia and seizure on the neuroendocrine hypothalamus, particularly neural substrates involved in regulation of the pituitary-adrenal axis, and 2) the differential effects of acute and chronic stress on the regulation of specific mRNA and peptide expression in activated neurons. 3) In addition to its neuroendocrine function, CRF also functions as an excitatory neurotransmitter/neuromodulator in extrahypothalamic brain sites. Studies in this laboratory suggest that extrahypothalamic CRF is significantly increased following specific brain insults and may play a role in ischemic and seizure brain damage. Investigations, which address the association of CRF induction following a brain insult with neuropathological processes, the administration of a CRF receptor antagonist to protect against the neurodegeneration and direct neurotoxic effects of CRF on neurons, are being pursued. Elucidation of the mechanisms responsible for neuronal vulnerability to brain insults will aid in the development of therapeutic drug interventions which selectively target the neuronal population most susceptible to ischemic or seizure damage, and thereby protect against neurodegeneration. Immunocytochemical localization of neuropeptides /neurotransmitters, in situ hybridization of neuropeptide gene expression, and tissue culture techniques are being employed in this research.
Pretel, S., C.D. Applegate and D.T. Piekut. Apoptotic and necrotic cell death following kindling induced seizures. Acta Histologica, 99:71-79, 1997.
Callahan, T.A. and D.T. Piekut. Differential FOS expression induced by IL-1ß and IL-6 in rat hypothalamus and pituitary gland. J. Neuroimmunol., 73:207-211, 1997.
Samoriski, G.M., D.T. Piekut, and C.D. Applegate. Differential spatial patterns of Fos induction following generalized clonic and generalized tonic seizures. Exp. Neurol., 143:255-268, 1997.
Kellogg, C.K., G.B. Awatramani and D.T. Piekut. Adolescent development alters stressor-induced FOS immunoreactivity in rat brain. Neurosci., 83: 681-689, 1998.
Samoriski, G.M., D.T. Piekut and C.D. Applegate. Regional analysis of the patterns of Fos induction in brain following a seizure: Dependence on seizure history and seizure phenotype. Neuroscience, 84:1209-1222, 1998.
Piekut, D.T. and B. Phipps. Increased corticotropin-releasing factor immunoreactivity in select brain sites following kainate elicited seizures, Brain Research, 781:100-113, 1998.
Blair, M.L., A. Want, J.A. Olschowka and D.T. Piekut. Role of paraventricular nucleus parvicellular neurons in the compensatory responses to graded hemorrhage, Am.J. Physiol., 275: R278-R285, 1998.
Callahan, T.A., J.A. Moynihan and D.T. Piekut. Central nervous system activation following peripheral chemical sympathectomy: implications for neural-immune interactions, Brain, Behavior and Immunity, 12:230-241, 1998.
Piekut, D.P. and B Phipps. (1999) Corticotropin-releasing factor immunolabeled fibers in brain regions with localized kainate neurotoxicity, Acta Neuropathology 98:622-628, 1999.
Blair, M. L., R. L. Parman-Jaworski, A. Want, and D. T. Piekut. Parabrachial nucleus modulates cardiovascular responses to blood loss. Am. J. Physiol. 280: R1141-48, 2001.
Jaworski, R.L., D. Piekut, and M.L. Blair. Pregnancy alters lateral parabrachial nucleus but not hypothalamic Fos expression following hypotensive hemorrhag Brain Research Bulletin, 57: 595-602, 2002.
A Hiwatashi (P). R.Sidhu, RK Lee, R Deguzman, DT Piekut, PA Westesson: Kyphoplasty increases vertebral body height more than vertebroplasty. A cadaveric study, Radiology 237 (3): 1115-1119, 2005.