We found that adult rats subjected to MD during the SP treated with two different broadly specific inhibitors (valproic acid and sodium butyrate) of histone deacetylases (HDACs) could completely recover the loss of visual acuity assessed electrophysiologically using visual evoked potentials (VEPs). Using a protocol of longitudinal assessment of visual acuity, we found that the deprived eye of adult long-term MD rats treated with valproic acid recovered normal levels of behavioral visual acuity. Animals were used in accordance with protocols approved by
the Italian Minister for Scientific Research. All experimental procedures conformed to the European Communities Council Directive number 86/609/EEC. Forty-one Long–Evans black hooded rats (Charles River, Italy) were used for the FK866 mouse behavioral, electrophysiological and biochemical experiments. The animals were housed in groups of two or three in a room with a temperature of 21°C and a 12-h light–dark cycle, and food and water available ad libitum. Rats were anesthetized with avertin (1 ml/hg) and MD was performed through eyelid suturing at postnatal day (P)21 (Pizzorusso et al., 2006). Lid margins were trimmed and sutured with 6-0 silk. Animals were allowed to recover from anesthesia and were returned to their cages. Eyelid closure was inspected daily until complete cicatrisation. Rats showing occasional lid reopening (observed with a surgical microscope)
were not included in the experiments. Adult rats (P120-130) were then subjected to RS, under anesthesia. The long-term deprived eye was
reopened using thin scissors, while the other eye was sutured shut. Great care was taken to Osimertinib order reopen the Ibrutinib mouse eye and to prevent opacities of the reopened eye by topical application (twice daily) of Tobradex cream (tobramycin and dexamethason; Alcon, Italy) onto the cornea during the first 3 days of RS. Again, subjects showing spontaneous lid reopening or eye anomalies were excluded. After 5 days of recovery from RS surgery, rats treated with daily intraperitoneal cronic administration (for an average of 25 days) of valproic acid (300 mg/kg in 0.9% saline at a concentration of 50 mg/mL) or sodium butyrate (1.2 g/kg in 0.9% saline at a concentration of 240 mg/mL) or vehicle (0.9% saline). Behavioral sessions began 2 h after the injection. After decapitation, brains were removed rapidly and frozen on dry ice. A cortical area corresponding to visual cortex was then homogenized in a hypotonic lysis buffer containing (in mm) Tris (pH 7.5), 10; EDTA, 1; sodium pyrophosphate, 2.5; b-glycerophosphate, 1; sodium orthovanadate, 1; and phenylmethylsulfonylfluoride, 1; with aprotinin, 10 mg/mL; leupeptin (Sigma, Italy), 10 mg/mL; and igepal CA-630, (Sigma Aldrich, Italy) 1%. Histones were extracted from the nuclear fraction by the addition of five volumes of 0.2 m HCl and 10% glycerol, and the insoluble fraction was pelleted by centrifugation (18 000 g; 30 min; 4°C).