FIGURE 5.

Inhibition of either 5-HT_2A or M₃R protects against light-induced atRAL-mediated photoreceptor degeneration in Abca4^−/−Rdh8^−/− mice. A, 4- to 5-week-old Abca4^−/−Rdh8^−/− mice were exposed to white light at 10,000 lux for 30 min after pretreatment with either vehicle control (DMSO) or the 5-HT_2A receptor antagonist, ketanserin. B, the M₃R antagonist, 4-DAMP, was independently tested and compared with a vehicle control (DMSO) in light-exposed Abca4^−/−Rdh8^−/− mice. Seven days later, retinal histological examination (63×) (a, * indicates disrupted and reduced length of outer/inner segments) and measurements of ONL thickness (b) were performed.