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PRC Atlas

An Atlas of Phase Responses Curves for Circadian and Circatidal Rhythms

A Phase Response Curve (PRC) is a plot of phase-shifts as a function of circadian phase of a stimulus such as light pulses, temperature pulses, or pulses of drugs or chemicals. The PRC Atlas is a collection of hundreds of published and unpublished PRCs. Compiling the Atlas was initiated by Dr. Colin Pittendrigh (1919-1996) and Dr. Pat DeCoursey (University of South Carolina) in 1977. We present here the latest version of the Atlas compiled by Carl Johnson in 1990s.


The idea of compiling and standardizing all published PRCs into a single volume originated with Dr. Colin Pittendrigh. He decided that it would be a good project for the participants of the 1977 Clocks Workshop, held at Hopkins Marine Station, Pacific Grove, California. He then enlisted the aid of Dr. Pat DeCoursey to direct the endeavor. About 40 PRCs were standardized that summer under her guidance. Dr. Pittendrigh then asked me to complete the task, which I have accomplished with the help of many other people. In particular I thank the following: Evelyn Parker for compiling the Drosophila pseudoobscura PRCs, Grace Monty and Sharon Pagni for typing/word processing, Jayati Kesavan and Bill Crouch for plotting and proof-reading, and Dr. Van Gooch for putting the PRC Atlas on computer diskettes. I also thank numerous other people for advice and encouragement- in particular, Drs. Terry Page and Pat DeCoursey.

Carl Johnson

  Before downloading the PRC Atlas, if you would like to know more about PRCs, please take a look at the following articles.

 A functional analysis of circadian pacemakers in nocturnal rodents (by Pittendrigh and Daan, 1976)

 Phase Response Curves: What can they tell us about circadian clocks? (1992)

 Forty years of PRCs: What have we learned? (1999)

 Entrainment of circadian programs (2003)

  PDF version of PRC Atlas

The PDF version of the PRC Atlas can be accessed here. [Download PDF version]

  Hardcopy version of PRC Atlas

      Johnson, C.H. (1990)
An Atlas of Phase Responses Curves for Circadian and Circatidal Rhythm.
      , 715 Pages, Department of Biology, Vanderbilt University, Nashville.

  Computer software versions of PRC Atlas

The PRC Atlas was laboriously converted to computer files by Dr. Van Gooch (University of Minnesota). These computer files are the basis of two user-friendly computer program versions of the PRC Atlas: one for PCs, written by Dr. Mark Stokes (Monash University) and the other for Macintoshs by Dr. Takao Kondo (Nagoya University).

   Microsoft Excel version

The PRC Atlas for MS- Excel was developed by Dr. Mark A. Stokes. The program may be used on any PC compatible computer using a minimum of DOS 5.0 with Windows 3.x and Microsoft Excel 5. It is best run with Microsoft Excel 7. on Windows system. The program is designed to run on 800x600 SVGA monitors (file: prc6x8.xls), or monitors with a resolution equal to or greater than 1024x768 (file: prcatlas.xls). [Download Excel version

  Comments on the Standardized Format