Journal: eLife

Article Title: Neurexins in serotonergic neurons regulate neuronal survival, serotonin transmission, and complex mouse behaviors

doi: 10.7554/eLife.85058

Figure Lengend Snippet: ( A ) Protocol for fear conditioning. Fear conditioning was p×erformed over 4 days. Mice were presented with two different auditory cues, one paired (yellow speaker) with a foot shock (yellow thunderbolt) and one unpaired (green speaker). ITI: intertrial interval. ( B ) Cntl ( n = 14) and Fev/RFP/NrxnTKO ( n = 11) mice both showed differences in freezing behavior across the presentations associated with the foot shock (CS+) (two-way repeated measures analysis of variance [ANOVA]: stimulus main effect, F 2.607,59.97 = 45.06, #### p < 0.0001). No differences were seen between groups (two-way repeated measures ANOVA: genotype main effect, F 1,23 = 0.00339, p = 0.9541; stimulus × genotype interaction, F 4,92 = 0.2652, p = 0.8996). ( C ) Among Cntl and Fev/RFP/NrxnTKO, freezing to the CS+ was increased relative to the CS− (stimulus with no association between auditory cue and foot shock) (two-way repeated measures ANOVA: stimulus main effect, F 1,23 = 85.22, #### p < 0.0001), but no differences were detected between groups (two-way repeated measures ANOVA: genotype main effect, F 1,23 = 1.67, p = 0.2091; stimulus × genotype interaction, F 1,23 = 0.03121, p = 0.8613). ( D ) Fev/RFP/NrxnTKO mice showed no altered freezing behavior during contextual recall (unpaired two-tailed Student’s t -test: t 23 = 0.01457, p = 0.9885). ( E ) Protocol for object interaction test. ( F ) Cntl ( n = 15) and Fev/RFP/NrxnTKO ( n = 12) showed no preference for identical objects on day 1 (two-way repeated measures ANOVA: stimulus main effect, F 1,25 = 2.606, p = 0.119; genotype main effect, F 1,25 = 0.02422, p = 0.8776; stimulus × genotype interaction, F 1,25 = 0.1923, p = 0.6648) and day 2 (two-way repeated measures ANOVA: stimulus main effect, F 1,25 = 3.18, p = 0.0867; genotype main effect, F 1,25 = 0.27, p = 0.6079; stimulus × genotype interaction, F 1,25 = 0.1825, p = 0.6729) and preferred the novel object over the familiar object on day 3 (two-way repeated measures ANOVA: stimulus main effect, F 1,25 = 129.6, p < 0.0001; genotype main effect, F 1,25 = 0.1452, p = 0.7064; stimulus × genotype interaction, F 1,25 = 0.03164, p = 0.8603). ( G ) The preference ratio for the objects differed across days (two-way repeated measures ANOVA: day main effect, F 1.932,48.3 = 47.7, p < 0.0001), but no differences were seen between groups (two-way repeated measures ANOVA: genotype main effect, F 2,50 = 0.008519, p = 0.9272; day × genotype interaction, F 2,50 = 0.1781, p = 0.8374). ( H ) Cntl ( n = 12) and Fev/RFP/NrxnTKO ( n = 12) mice showed no differences in the number of marbles buried (unpaired two-tailed Student’s t -test: t 22 = 1.491, p = 0.1502). ( I ) Left , no differences in grooming time were observed between groups (unpaired two-tailed Student’s t -test: t 22 = 0.04104, p = 0.9676). Right , the number of grooming episodes was similar between groups (unpaired two-tailed Student’s t -test: t 22 = 0.5443, p = 0.5917).

Article Snippet: Using the ANY-maze fear conditioning system (Ugo Basile SRL), mice were placed in a fear conditioning cage (17 × 17 × 25 cm) in a sound-attenuating box.

Techniques: Two Tailed Test