Acoustic startle response (ASR) and sensorimotor gating (i.e. prepulse inhibition: PPI).

<p>(A) ASR to different acoustic startle stimuli, (B) habituation to a 120dB startle stimulus across test trials (i.e. averaged across 3 blocks of 5 trials each), and (C) percentage prepulse inhibition [%PPI] across different prepulse intensities (i.e. 74dB, 82dB, and 86dB)–calculated for the middle 120dB ASR block. Data for control (WT) and <i>Mic-1</i> knockout mice (<i>Mic-1</i> KO) of both males (M) and females (F) are shown as means + SEM. A significant ‘sex’ effect (<i>p</i> < .05) and ‘startle block’ by ‘sex’ by ‘genotype’ interaction effect (<i>p</i> = .03) were found for ASR habituation. Only female mice and control mice (both <i>p</i> = .002) displayed intact ASR habituation. %PPI across prepulse intensities revealed a main effect of ‘genotype’ (<i>p</i> < .001) and a ‘sex’ by ‘prepulse intensity’ interaction (<i>p</i> = .01).</p

Anxiety-related behaviours in the elevated plus maze (EPM) and the open field test (OF).

<p>(A) Percentage time spent on open arms (excluding centre time) [%], (B) percentage of entries into open arms [%], (C) time spent in the central zone of the OF [s], and (D) ratio of total distance travelled in the central zone of the OF. Data for control (WT) and <i>Mic-1</i> knockout mice (<i>Mic-1</i> KO) of both males (M) and females (F) are shown as means + SEM. In the EPM, <i>Mic-1</i> mice spent more time (<i>p</i> = .002) and also showed more locomotion (<i>p</i> = .01) in the open arms. In the OF, knockout mice spent more time (<i>p</i> < .0001) and showed more locomotion (<i>p</i> < .0001) in the centre.</p

Behaviours of wild type-like control (WT) and <i>Mic-1</i> knockout mice (<i>Mic-1</i> KO) of both sexes in elevated plus maze (EPM), the open field (OF), the spontaneous alternation task (SA), the social interaction test (SI), and prepulse inhibition (PPI).

<p>There was a main effect of ‘genotype’ for number of arm entries in the EPM [F(1,48) = 7.4, <i>p</i> = .009] and for small motor movements [F(1,48) = 11.7, <i>p</i> = .001] as well as for percentage prepulse inhibition [%PPI: F(1,48) = 11.5, <i>p</i> = .001].</p

Fear-associated memory to context and cue.

<p>(A) Total time spent <i>freezing</i> [s] during the context test, (B) time spent <i>freezing</i> [s] across 1-min blocks in the context test, (C) time spent <i>freezing</i> [s] in the 1-min block prior and post cue presentation, and (D) time spent <i>freezing</i> [s] across 1-min blocks during cue presentation. Data for control (WT) and <i>Mic-1</i> knockout mice (<i>Mic-1</i> KO) of both males (M) and females (F) are shown as means + SEM. Comparing freezing in the last min prior to cue onset with the first min post cue onset revealed effects of ‘sex’ (<i>p</i> < .0001) and ‘genotype’ (<i>p</i> = .005) as well as a significant ‘1 min block’ by ‘genotype’ interaction (<i>p</i> = .01). Three mice (1x male <i>Mic</i>-1 KO, 1x female WT, and 1x male WT) jumped out of the test chamber during conditioning and were therefore not included in the statistical analysis.</p

Habituation of locomotive response to novelty in the open field (OF).

<p>Overall distance travelled in the open field [cm] across 5-min blocks. Data for control (WT) and <i>Mic-1</i> knockout mice (<i>Mic-1</i> KO) are shown for males (M) and females (F) as means + SEM. There was a significant ‘5 min block’ x ‘genotype’ interaction (<i>p</i> < .0009).</p