Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Light-dark cycle synchronization of circadian rhythm in blind primates. | Journal of Circadian Rhythms BioMed Central Short paper Open Access Light-dark cycle synchronization of circadian rhythm in blind primates Mayara MA Silva Alex M Albuquerque and John F Araujo Address Laboratório de Cronobiologia Departamento de Fisiologia CB UFRN Natal Brazil Email Mayara MASilva - mmytzi@ Alex M Albuquerque - alnmda@ John F Araujo - araujo@ Corresponding author Published 06 September 2005 Received 17 August 2005 ._- .m I ioz OI - in Accepted 06 September 2005 Journal of Circadian Rhythms 2005 3 10 doi 1740-3391-3-10 This article is available from http content 3 1 10 2005 Silva et al licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Recently several papers have shown that a small subset of retinal ganglion cells RGCs which project to the suprachiasmatic nucleus SCN and contain a new photopigment called melanopsin are the photoreceptors involved in light-dark entrainment in rodents. In our primate colony we found a couple of common marmosets Callithrix jacchus that had developed progressive and spontaneous visual deficiency most likely because of retinal degeneration of cones and or rods. In this study we evaluated the photoresponsiveness of the circadian system of these blind marmosets. Methods Two blind and two normal marmosets were kept in cages with a controlled light-dark cycle LD to study photoentrainment masking and phase response to a dark pulse. Results Blind marmosets were entrained with the new LD cycle when light onsets were delayed and advanced by 6 hours. In constant light conditions blind marmosets free-ran with a period of hours while normal animals free-ran with a period of hours. All .
