49
vation curve and time course, and that these values are characteristic of the HCNl isoform
(figure 3.1 Al-4, Bl-4). Our whole-cell data from salamander rods is similar to reports from
other researchers [1, 75, 78, 54], however, we use the intact retina to avoid the drawbacks of
dissociated cells and standardize recording conditions for rods and cones. With whole-cell
voltage clamp, we demonstrate that the activation time course of rod and cone 7⅛ is similar to
homogeneously expressed HCNl channels (figure 3.1 A3, B3, table 3.1). Although the rod
and cone half activation potentials are more hyperpolarized than the expressed HCN1 chan-
nels, this is a known difference between in vivo vs. expressed HCNl channels [3]. While
other researchers have shown that the HCNl isoform is responsible for Ih in rabbit rods
[31], we demonstrate that this is true not only for salamander rods, but also for cones. Our
immunohistochemical and western blot experiments support our finding that HCN1 chan-
nels are responsible for the 1⅛ current in rods and cones (figure 3.2). These results, which
agree with experiments on the rat retina [83], show anti-HCNl antibodies strongly labeling
rods and cones. Our western blot experiments show the HCNl antibody binds to a 60 kDa
protein, which was also noted by Müller et al in the rat retina [83]. Given the specificity
predicted by a BLASTp search (see Results and Mehtods) and demonstrated in the blot itself
(figure 3.2 Al), we believe the 60 kDa protein represents a truncated form of HCNl in the
retina. Whether this product is active or not warrants further investigation.
More intriguing information
1. The name is absent2. Pupils’ attitudes towards art teaching in primary school: an evaluation tool
3. Social Irresponsibility in Management
4. Geography, Health, and Demo-Economic Development
5. The name is absent
6. AN ECONOMIC EVALUATION OF COTTON AND PEANUT RESEARCH IN SOUTHEASTERN UNITED STATES
7. Publication of Foreign Exchange Statistics by the Central Bank of Chile
8. The Response of Ethiopian Grain Markets to Liberalization
9. How does an infant acquire the ability of joint attention?: A Constructive Approach
10. The name is absent