Fig. 5

G_q protein-coupled intracellular Ca²⁺ ([Ca²⁺]_i) mobilization is impaired in genetic Perk knockout primary cortical neurons. a Western blot analysis confirmed almost complete knockdown of PERK in the cerebral cortex of BrPKO mice at postnatal day 0 (BrPKO: Nestin-Cre Perk-floxed; *** p < 0.001, two-tailed student’s t-Test). b No difference in synapse density was observed between WT and BrPKO primary cortical neurons. Representative image on the left shows the immunofluorescent staining of Synapsin 1(red) and MAP2 (green) in primary cortical neurons. Synapse density quantification in the bar graph on the right represents pooled data from 3 mice per genotype (5 neurons were randomly picked for synapse density quantification per animal, n = 15 for each genotype; WT and BrPKO neurons were cultured from the pups in the same litter; n.s. not significant, two-tailed student’s t-Test). c DHPG stimulated [Ca²⁺]_i rise is impaired in genetic Perk KO primary cortical neurons. In the representative graph on the left, each Ca²⁺ trace represents the average of 8–10 neurons that were imaged from the same coverslip. Basal Ca²⁺ oscillation over 100 sec before treatment and DHPG-stimulated [Ca²⁺]_i rise over 200 sec were quantified by calculating the area under the curve (AUC). Final analysis is presented as AUC/100 sec and shown in the bar graph on the right (WT n = 44, BrPKO n = 34; *** p < 0.001, two-tailed student’s t-Test)