Fig. 2. CALM bidirectionally controls synaptic plasticity and modulates learning.

(A) Deletion of CALM in KO^Tub and KO^EMX mice. Brain lysates were analyzed by immunoblotting. Protein levels of CALM KO mice were normalized to WT littermates. (B and C) LTP induced by single theta-burst stimulation (TBS) is increased in 2-month-old CALM KO^EMX mice. (B) Graph shows normal presynaptic post-tetanic short-term potentiation measured immediately after TBS and increased postsynaptic LTP in CALM KO^EMX mice. Top: Representative fEPSPs recorded 0 to 10 min before (solid line) and 50 to 60 min after TBS (dashed line). Scale bar, 0.5 mV and 10 ms. (C) LTP values quantified as percent increase of the responses during the last 10 min. (D to G) LTD is reduced in 2-month-old CALM KO^EMX mice and severely impaired in 2-week-old CALM KO^EMX mice. (D and F) Top: Representative fEPSPs recorded 0 to 10 min before (solid line) and 50 to 60 min after LFS (dashed line). Scale bars, (D) 1 mV and 10 ms and (F) 0.5 mV and 10 ms. (E and G) LTD values quantified as percent decrease of the responses during the last 10 min. (H to J) CALM KO^EMX mice show improved spatial learning. (H) Average escape latency over 5 days of training. Depiction of individual escape latencies for days 2 (I) and 3 (J), where CALM KO^EMX mice outperformed controls. Statistics Table 1.