Rod Sensitivity of Neonatal Mouse and Rat
نویسندگان
چکیده
We have measured the sensitivity of rod photoreceptors isolated from overnight dark-adapted mice of age P12 (neonate) through P45 (adult) with suction-pipette recording. During this age period, the dark current increased roughly in direct proportion to the length of the rod outer segment. In the same period, the flash sensitivity of rods (reciprocal of the half-saturating flash intensity) increased by approximately 1.5-fold. This slight developmental change in sensitivity was not accentuated by dark adapting the animal for just 1 h or by increasing the ambient luminance by sixfold during the prior light exposure. The same small, age-dependent change in rod sensitivity was found with rat. After preincubation of the isolated retina with 9-cis-retinal, neonatal mouse rods showed the same sensitivity as adult rods, suggesting the presence of a small amount of free opsin being responsible for their lower sensitivity. The sensitivity of neonate rods could also be increased to the adult level by dark adapting the animal continuously for several days. By comparing the sensitivity of neonate rods in darkness to that of adult rods after light bleaches, we estimated that approximately 1% of rod opsin in neonatal mouse was devoid of chromophore even after overnight dark adaptation. Overall, we were unable to confirm a previous report that a 50-fold difference in rod sensitivity existed between neonatal and adult rats.
منابع مشابه
Diffusible rod-promoting signals in the developing rat retina.
We previously developed a reaggregate cell culture system in which embryonic rat retinal neuroepithelial cells proliferate and give rise to opsin-expressing rod photoreceptor cells (rods) on the same schedule in vitro as they do in vivo. We showed that the proportion of neuroepithelial cells in the embryonic day 15 (E15) retina that differentiated into opsin+ rods after 5-6 days in such culture...
متن کاملSteroid Production and Follicular Development of Neonatal Mouse Ovary during In Vitro Culture
متن کامل
بررسی اثر آگونیست و آنتاگونیست های مختلف گیرنده هیستامینی بر هماهنگی حرکتی موش صحرایی در تست Rota rod
Background and purpose: Sedation is regarded as a common side effect of most antihistamines, and limits the clinical utility of classical antihistaminic agents, while newer antihistamines are nonsedating. Çonsidering the importance of this phenomenon in the present study, the role of different histamine receptor mechanisms in mediating the sedation were investigated in rat rota rod test. M...
متن کاملDetection of Experimental Cryptosporidiosis in Neonatal Mice and Rats by Nested-PCR
Purpose: The purpose of this study is to model Cryptosporidiosis in laboratory animals. The parasites were inoculated into animalsand thenmultiplied. The process of proliferation was compared to controlCryptosporidiosis in humans. Materials and Methods: Twenty-five laboratory mice (4-7 days of age) and twenty-five laboratory rats (5 days of age) were assigned to the category I while the cat...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of General Physiology
دوره 126 شماره
صفحات -
تاریخ انتشار 2005