Figure 4.

Chronic lithium inhibits the peak elevation in [Ca²⁺]_i after exposure to glutamate in cerebellar granule neurons. Cerebellar granule neurons were pretreated with LiCl (1–5 mM) for 7 days and [Ca²⁺]_i was then measured by using microfluorimetry in cells prelabeled with the fluorescent Ca²⁺ indicator fura-2. Glutamate-induced [Ca²⁺]_i increase was elicited by a 10-sec pulse with glutamate (100 μM)/glycine (10 μM) followed by a 60-sec wash. (A) Graphic tracing of glutamate/glycine-induced [Ca²⁺]_i in untreated and lithium-treated cerebellar granule cells. (B) Averaged peak of [Ca²⁺]_i from three cultures of cells pretreated for 7 days with various concentrations of LiCl (1–5 mM). Data are the mean ± SEM of percent of glutamate/glycine response in untreated cells. ∗, P < 0.05; ∗∗, P < 0.01; ∗∗∗, P < 0.001, compared with the group treated with glutamate/glycine alone without lithium pretreatment (one-way ANOVA with Bonferroni–Dunn test). The 100% values are 645 ± 20 nM.