Fig. 4.

Enhanced sedative/hypnotic effects in response to α₂AR stimulation in Sp(−/−) mice. A, hypnotic response was evaluated by Rotarod latency in mice with different genotypes in response to a bolus injection of 0.19 or 0.75 mg/kg clonidine. Values represent mean ± S.E.M. Numbers in parentheses represent the number of mice tested. ∗, p < 0.05. B, relative spinophilin protein content in these mice was detected by Western analysis of brain lysates from WT, Sp(+/−), and Sp(−/−) mice. Values represent mean ± S.E.M. n = 3 for each genotype. C, prolonged sleep-time in response to UK14,304 observed in mice lacking spinophilin expression. Sleep time, estimated by the duration of LORR, was measured for WT and Sp(−/−) mice after injection of 5 mg/kg i.p. UK14,304, as described under Materials and Methods. Values represent mean ± S.E.M. ∗∗∗, p < 0.001, n = 5 for each genotype.