Current Projects

Measuring the influence of mper2 and other clock genetic mutations upon the function and photic entrainment of the mammalian circadian pacemaker

Formal analyses of circadian entrainment – establishing links between the circadian sensitivity to brief pulses and full entrainment to complete photoperiods.

Quantitative analyses of complex behavior using bioinformatics and data mining techniques (collaboration with Dr. Chih Lai, UST Graduate Programs in Software)

Immunologically medicated fatigue (collaboration with Dr. Jian Ding, University of Minnesota, Minneapolis, MN).

Recent Publications and Presentations

Student names are in bold.

Nelson, D. E. and J. S. Takahashi.  1999.  Integration and saturation within the circadian photic entrainment pathway of hamsters. American Journal of Physiology 277(5 Pt 2):R1351‑61.

Khammanivong, A. and D. E. Nelson. 2000.  Saturating light stimulation causes a temporary reduction in the photic sensitivity of the mouse circadian system.  Journal of Biological Rhythms 15: 393 - 405.

Langseth, A., Laliberte, M., Lutterman, A. and D.E. Nelson. 2000.  Sensitivity to stimulus duration and illuminance level for the circadian photic entrainment pathway in the C57Bl/6 mouse.  (In preparation).

Sampair, C., Buhr, E. and D.E. Nelson.  2000.  Photic sensitivity measurements for mouse circadian resetting: Focus upon stimulus duration.  (In preparation).

Published Abstracts / Student Presentations:

Derek Benson, Kevin Zenga and Dwight E. Nelson, 1998, Establishing an assay for zebrafish circadian rhythms: Using LabView image acquisition to quantify swimming activity.  Journal of the Minnesota Academy of Science 62: 8.

Ali Khammanivong, John Hayden and Dwight E. Nelson, 1998, Functional characterization of the visual entrainment pathway for the mouse circadian pacemaker.  Journal of the Minnesota Academy of Science 62:28.

Ali Khammanivong, and Dwight E. Nelson, 1998, The mouse circadian system becomes unresponsive to light after “saturating” light-induced phase delays.  Soc. Neurosci. Abstr. 24:1916.

Alison Lutterman, Mark Laliberte, and Dwight E. Nelson, 1999. Sensitivity to stimulus duration and illuminance level for the circadian photic entrainment pathway in the C57Bl/6 mouse. Journal of the Minnesota Academy of Science 63: 15.

Mark Laliberte, Alison Lutterman and Dwight E. Nelson. 1999.  Sensitivity to stimulus duration for the circadian photic entrainment pathway in the C57Bl/6 mouse.  Journal of the Minnesota Academy of Science 63: 14.

Ethan D. Buhr, Mark Laliberte, Alison Lutterman and Dwight E. Nelson. 1999. Sensitivity of the Mouse Circadian System to Photic Stimulus Duration and Intensity.  Soc. Neurosci. Abstr. 25, Part 1: 351.

Jonathan J. Waataja, Dwight. E. Nelson. 2000. A novel technique for measuring circadian rhythms of total movement using LabView image acquisition: Measurements of light‑induced phase shifts with and without running wheels.  Soc. Neurosci. Abstr. 26, 209.

Christopher Kasal, Ethan D. Buhr and Dwight Nelson. 2001. Assessment of photic sensitivity in mice with the Clock mutation.  Journal of the Minnesota Academy of Science  65.

Lisa Tracy and Dwight E. Nelson. 2001.  Sensitivity measurements of the mouse circadian system to light using complete Light‑Dark cycles: Comparisons with sensitivity measured using a phase shift assay.  Minnesota Academy of Science Poster Session, St. Paul, MN.  April, 2001.

Lisa N. Tracy and Dwight E. Nelson. 2002.Circadian function and pacemaker resetting in mPer2 knockout mice. Journal of the Minnesota Academy of Science 66:.32.  (Lisa received a Winchell Award for Undergraduate Research  for her presentation at this meeting). 

L.N. Tracy, Hruby, L.A. Stahler, P.A., Langseth, A..J. & Nelson, D.E.  2002. Respon­sive­ness of the circadian photic entrainment pathway in mPer2 mutant mice. Society for Neuroscience Abstracts 28.

A.J. Langseth, McNamara, L.S. Tracy, L.N.  Stahler,P.A.  and D.E. Nelson, 2003 (pending). Responsiveness of the circadian pacemaker in steady-state and non-steady-state conditions. Submitted to the Minnesota Academy of Science Winchell Symposium.

L.S. McNamara,  Langseth, A.J.,  Hruby, L.A., Moon, G., Stahler, P.A.  and D.E. Nelson, 2003 (pending).  The influence of circadian phase of training upon spatial leaning in c57BL/6 mice.  Submitted to the Minnesota Academy of Science Winchell Symposium.

C.Lai and D.E.Nelson,  2003, Data mining methods to detect and quantify partial periodic patterns in circadian rhythms of locomotor activity:  A potential screening tool for analyses of complex behaviors, Bioinformatics Session, Minnesota Academy of Science Annual Meeting.  April, 2003. University of Minnesota,  St. Paul, MN.

A.J. Langseth, McNamara, L.S. Tracy, L.N.  and D.E. Nelson, 2003.  Changes in the photic responsiveness of the mouse circadian pacemaker during initial cycles in constant darkness.  Society for Neuroscience Abstracts.  (Accepted for presentation).

Grant Applications and Awards

2003        Research Grant, Project title: “Photic Sensitivity of the Circadian Entrainment Pathway in mice carrying the mPer2-mutation.”  National Institutes of Health, Division of Mental Health,  April, 2003 - Mar, 2006.  (MH-60122-02)

1999     Research grant, Project title: “Photic Sensitivity of  the Mouse Circadian Entrainment Pathway”. National Institutes of Health: Division of Mental Health (MH-60122-01 R15).  

1997     Research Assistance Grant, University of St. Thomas Faculty Development Program.  Project title: “Characterization of circadian photic sensitivity in the C57BL/6 mouse.”

1996     Instrumentation and Laboratory Improvement Award,  Project title: “Integration and Expansion of Organismal Biology Courses at the University of St. Thomas.” National Science Foundation  (DUE-9651421).

Student Researchers

Recent research students below from left to right:  
C.J. Lindor, Lisa Tracy, Dwight Nelson, Kristin Anderson (with bucket), David Turnbloom, Abraham Langseth, Leo McNamara

Courses

Neuroscience Seminar Fall 2002 on Circadian Clocks
Back row L to R:  Alex Blissenbach, Krista Kudma, Anne Paulson, 
Andrew Campbell, and Brianna Sucik
Front row L to R:  Karl Menk, Adam Sager, and Michelle Halley

Click here to view their final presentation