Light- and focus-dependent expression of the transcription factor ZENK in the chick retina.
Ocular growth and refraction are regulated by visual processing in the retina. We identified candidate regulatory neurons by immunocytochemistry for immediate-early gene products, ZENK (zif268, Egr-1) and Fos, after appropriate visual stimulation. ZENK synthesis was enhanced by conditions that suppress ocular elongation (plus defocus, termination of form deprivation) and suppressed by conditions that enhance ocular elongation (minus defocus, form deprivation), particularly in glucagon-containing amacrine cells. Fos synthesis was enhanced by termination of visual deprivation, but not by defocus and not in glucagon-containing amacrine cells. We conclude that glucagon-containing amacrine cells respond differentially to the sign of defocus and may mediate lens-induced changes in ocular growth and refraction.
Department of Anatomy, Neuroscience Research Group, University of Calgary Faculty of Medicine, 3330 Hospital Drive N.W., Calgary, Alberta T2N 4N1, Canada. ajfische@u.washington.edu
A J
AJ
Fischer
J J
JJ
McGuire
F
F
Schaeffel
W K
WK
Stell
D000221:Adaptation, Ocular; D000818:Animals; D002645:Chickens; D004268:DNA-Binding Proteins / Q000235:genetics*; D005786:Gene Expression Regulation / Q000502:physiology / Q000528:radiation effects*; D017874:Immediate-Early Proteins / Q000235:genetics*; D007150:Immunohistochemistry; D008027:Light; D008297:Male; D009474:Neurons / Q000502:physiology / Q000528:radiation effects; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000502:physiology; D012160:Retina / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D014157:Transcription Factors / Q000235:genetics*
D004268:DNA-Binding Proteins; D017874:Immediate-Early Proteins; D016760:Proto-Oncogene Proteins c-fos; D016194:Receptors, N-Methyl-D-Aspartate; D014157:Transcription Factors