Figure 4.

Reduction of Ca²⁺ entry via L-VGCCs in TNC deficient mice. (A) Intracellular recording of the CA1 pyramidal cell response to theta-burst synaptic stimulation. In each burst, 2–3 action potentials were generated on depolarization peaks. (B) Changes of the fluorescence of the calcium indicator Oregon Green 488 BAPTA-1 during the response of CA1 pyramidal cell to TBS. The panel shows the difference in the fluorescence between two frames acquired with 400 ms exposure before and during the TBS. Scale bar: 40 μm. (C) The time-course of Ca²⁺ signal changes induced by application of the L-VGCC blocker nifedipine (horizontal bar). Mean values of Ca²⁺ signals 0–25 min before nifedipine application were set to 100%. (D) Summary of the reduction of theta-burst-induced Ca²⁺ signals by nifedipine. Means and SEM of signals measured repeatedly 5–25 min after nifedipine application in 12 TNC^+/+ and 10 TNC^−/− mice are presented, *p < 0.05, t-test.