Parvocellular (P-) and magnocellular (M-) cells in the marmoset LGN can receive prominent rod input up to relatively high illuminance levels (Kremers et al., 1997b). In the present paper, we quantify rod and cone input strengths under different retinal illuminance levels. The stimulus was based on the so-called "silent substitution" method. The activities of P- and M-cells of dichromatic animals were recorded extracellularly. We were able to adequately describe the response amplitudes and phases by a vector summation of rod and cone signals. At low retinal illuminance levels, the cells' responses were determined by rod and cone inputs. With increasing illuminances the strength of the cone input increased relative to the rod strength. But, we often found significant rod inputs up to illuminances equivalent to 700 td in the human eye or more. Rod input strength was more pronounced in cells with receptive fields at large retinal eccentricities. The phase differences between rod and cone inputs suggest that the rod signals lag about 45 ms behind the cone signals.

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BackgroundPatellar dislocation is common in young and active patients. The purpose of this study was to determine sporting activity following the medial reefing of patellar dislocation.MethodsOne hundred forty-four patients with objective patellar dislocation were treated between 2004 and 2013. Three groups were analyzed retrospectively with a minimum follow-up of 24 months: (1) primary dislocation that was treated with medial reefing without a recurrent dislocation until the day of follow-up (n = 74), (2) primary dislocation that was initially treated with medial reefing but with a recurrent dislocation until the day of follow-up (n = 44), and (3) medial reefing after failed conservative treatment (n = 26). Sporting activity was assessed using a widely-used sporting activity questionnaire and the Tegner score prior to the injury and at the follow-up (58.7 ± 22.6 months after the injury). Clinical outcomes were assessed using IKDC and Kujala score.ResultsThe Kujala score was 94.7 ± 9.3 for Group 1, 84.1 ± 16.6 for Group 2 and 93.4 ± 9.7 for Group 3. IKDC at the time of follow-up was 97.2 ± 9.3 for Group 1, 86.1 ± 14.6 for Group 2 and 95.1 ± 11.1 for Group 3. 91.9% of Group 1 and 92.3% of Group 3 were active in sports prior to their injuries and at the time of the follow-up. In Group 2, sporting activity reduced from 81.8 to 75.0%. In all groups, a shift from high performance to recreational sports was found.ConclusionsDespite good clinical results, sporting activity was reduced following patellar dislocation treated with medial reefing. Also, a shift from engagement in high- to low-impact sports among the participants was noted.

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