Fig. 1.

Increased LVA Ca²⁺ peak current in tottering, lethargic, andstargazer. A, Biocytin-filled thalamic neuron in the LDN of thalamus from wild-type mouse (C57BL/6J).B, Representative LVA current traces from TCs of the LDN in control, tottering, lethargic, andstargazer mice. The cell capacitance values of these four neurons were 101.25, 107.1, 95.5, and 95.34 pF, respectively. Holding potential, −70 mV. The membrane potential was prepulsed to −110 mV for 3 sec before stepping to −50 mV for 200 msec. Decay of the current was fitted by a single-exponential function (dotted line). No significant alterations in macroscopic current decay were found. The representative time constants τ for decay were 29.2, 29.7, 30.1, and 31.8 msec, respectively, in control, tg,lh, and stg mice. C, Elevated LVA Ca²⁺ current amplitude and peak current density from mutant TCs. LVA currents were evoked at the same membrane potential as described in B. The mean current amplitude and peak current densities were −926.3 ± 182.2 pA and 9.5 ± 1.3 pA/pF in control, 1514.9 ± 142 pA and 17.4 ± 1.2 pA/pF in stg, −1571.9 ± 106.8 pA and 17.63 ± 1.6 pA/pF in tg, and −1852.1 ± 118.9 pA and 19.6 ± 1.0 pA/pF in lh mice. *p < 0.05; **p < 0.01 versus control.