Effect of quinine on latency and amplitude of visual evoked potential P100 peak in male mice

Quinine is used for treatment of many disorders، such as malaria and rheumatoid arthritis. Besides good therapeutic effects، it may have multiple adverse effects. In this study، the effects of quinine on latency and amplitude in visual evoked potential (VEP) were evaluated. In this experimental study، 50 male Syrian mice were used as control. Five groups of ten mice received doses of 2. 5، 12. 5، 25، 50، and 62. 5 mg of quinine and one group of ten mice was given 70 mg acetone extract of Cinchona plant intraperitoneally for 14 days. The latency and amplitude of different groups in VEP were recorded. The latency was significantly increased، as parallel as dosage، in 14 days (P<0. 05)، while the amplitude was significantly decreased، as parallel as dosage، in 14 days (P<0. 05). Quinine resulted in significant increase of latency and decrease of amplitude and leaded to visual loss، possibly due to deposition of quinine on nerve fibers and cone-shaped and cylindrical cells leading to increase in latency phase of transmission from retina to fovea.