Figure 4.

SLM2 controls synaptic plasticity and function in a trans-synaptic manner

(A) Electrical stimulation of axons in the alveus and voltage-clamp recordings in genetically marked SST-positive interneurons in the s.o.

(B) Example traces of miniature excitatory postsynaptic currents (mEPSCs) in SST interneurons.

(C–E) Analysis of mEPSC amplitude (C), frequency (D), and rise and decay times (E). WT n = 17, ΔSST n = 18. Mean ± SEM. p values determined by corresponding t tests. For cumulative frequency distribution, Kolmogorov-Smirnov test.

(F) Mean ± SEM data of AMPAR-mediated EPSCs in SST interneurons of s.o in response to different stimulation intensities of axons in the alveus in ΔSST n = 17 versus WT n = 12. Two-way ANOVA with Šídák’s multiple comparisons test.

(G) Representative traces of evoked EPSCs during repetitive stimulation at 40 Hz in WT (black) and ΔSST (red). Group data of EPSCs normalized to the first peak in ΔSST n = 26 versus WT n = 26. Mean ± SEM. Two-way ANOVA with Šídák’s multiple comparisons test.

(H) Local optogenetic stimulation of SST+ neuron-mediated IPSCs in apical CA1 dendrites in WT and ΔSST mutants. Representative traces of inward and outward IPSCs evoked at increasing laser intensities in WT (black) and ΔSST (red). Mean ± SEM input-output curve of synaptic conductance underlying outward and inward PSCs.

(I) Quantification of velocity (cm/min) in open field, initial, and short-term memory (STM) test phases of novel object recognition (NOR) task. Animal numbers for each task are indicated. Mean ± SEM, unpaired t test.

(J and K) NOR interaction time (s) spent with a familiar (black) or novel (purple) object during a 5 min trial (paired t test) and discrimination index (unpaired t test). Mean ± SEM, WT n = 19 and ΔSST n = 12.