Document Detail

Circadian rhythms in the electroretinogram of the cockroach.
MedLine Citation:
PMID:  2979573     Owner:  NLM     Status:  MEDLINE    
Circadian regulation of the amplitude of the electroretinogram (ERG) of the cockroach Leucophaea maderae was investigated. Two components of the ERG exhibited circadian rhythms in amplitude. Interestingly, the peak amplitudes for the two rhythms were approximately 12 hr out of phase. The dominant corneal negative potential (the "sustained component") exhibited maximum amplitude during the subjective night. A second corneal negative potential (the "off-transient") was at a maximum during the subjective day. Intensity-response curves of the sustained component were measured at both the peak and trough of the rhythm. The results showed that the circadian rhythm in amplitude reflected a sensitivity change equivalent to 0.2-0.6 log unit of intensity. An effort was also made to identify the anatomical locus of the pacemaking oscillator for the ERG rhythm in a series of lesion experiments. Neural isolation of the optic lobe from the midbrain by bisection of the optic lobe proximal to the distal edge of the lobula had no effect on the circadian rhythm of ERG amplitude. Bisection of the optic lobe distal to the lobula abolished the ERG amplitude rhythm. These results suggest that the pacemaker is located in the optic lobe near the lobula; that its motion continues in the absence of neural connections with the rest of the nervous system; and that its regulation of ERG amplitude depends on neural pathways in the optic lobe.
S A Wills; T L Page; C S Colwell
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of biological rhythms     Volume:  1     ISSN:  0748-7304     ISO Abbreviation:  J. Biol. Rhythms     Publication Date:  1985  
Date Detail:
Created Date:  1992-01-15     Completed Date:  1992-01-15     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  8700115     Medline TA:  J Biol Rhythms     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  25-37     Citation Subset:  IM    
Department of General Biology, Vanderbilt University, Nashville, Tennessee 37325.
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MeSH Terms
Circadian Rhythm / physiology*
Motor Activity / physiology
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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