Documenta Ophthalmologica 104: 119–132, 2002. © 2002 Kluwer Academic Publishers. Printed in the Netherlands. An animal model for studying cone function in retinal detachment GERALD H. JACOBS 1,2 , JACK B. CALDERONE 1,2 , TSUTOMU SAKAI 2,3 , GEOFFREY P. LEWIS 2 and STEVEN K. FISHER 2,4 1 Department of Psychology; 2 Neuroscience Research Institute, 4 Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara CA 93106, USA; 3 Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan Abstract. In people, retinal detachment often leads to a significant loss in cone-based vis- ion. Most of the animal models commonly used for studying the consequences of retinal detachment have rod-dominated retinas. The purpose of this investigation was to evaluate the possibility that the ground squirrel, a rodent with a heavily cone-dominated retina, might provide a useful model for studying cone function in retinal detachment. Corneal ERGs were recorded from ground squirrels for large-field temporal modulations presented on a computer- controlled color monitor. Modulations were chosen to selectively stimulate either of the two classes of cone found in the ground squirrel retina. Under these test conditions, large and reliable cone ERGs could be readily recorded. In animals in which the retina had been sur- gically detached, the loss of cone signal was directly related to the number of cones in the detachment zone relative to the total cone population and that relationship did not differ for short-wavelength sensitive (S) and middle-wavelength sensitive (M) cones. Surgical reat- tachment produced a progressive recovery of cone-based signals. The ground squirrel seems likely to provide a useful animal model for studying the dynamics of cone function in retinal detachment and subsequent events. Key words: cone, cone-isolating stimuli, electroretinogram, ground squirrels, retinal detach- ment Introduction Retinal detachment initiates a chain of molecular and cellular events in the retina that culminates in loss of visual capacity, often including decreases in visual acuity, visual threshold elevations and alterations in color vision. It is an unfortunate fact that impaired vision often persists even after successful reattachment surgery. There has been considerable effort dedicated to un- derstanding the details of structural and functional changes following retinal detachment, frequently pursued with a view toward proposing and evaluating a variety of therapeutic interventions that might ameliorate visual loss [1–4]. Laboratory studies of retinal detachment typically involve the use of an an- imal model. Monkeys have been used on occasion, but most often the models