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. 2009 Sep 23;158(4):1131–1142. doi: 10.1111/j.1476-5381.2009.00378.x

Figure 7.

Figure 7

The effects of tanshinone I on memory impairment induced by MK-801 via extracellular signal-regulated kinase (ERK)–cAMP response element binding protein (CREB) signalling. (A) Effect of tanshinone I (1, 2 or 4 mg·kg−1, i.p.) on passive avoidance task latency. Tanshinone I was administered 40 min before, and MK-801 30 min before the acquisition trial. Data represent means ± SEM (n= 10 per group). *P < 0.05 versus vehicle controls, #P < 0.05 versus diazepam-treated mice. Latency increases induced by tanshinone I (4 mg·kg−1, p.o.) were reversed by U0126 (U, 1 nmol, i.c.v.) (an ERK1 and ERK2 inhibitor) (B). Tanshinone I was administered 40 min before, and MK-801 and/or U0126 30 min before the acquisition trial. Latencies were measured as described in Methods. Data represent means ± SEM (n= 6 per group). *P < 0.05 versus vehicle controls, #P < 0.05 versus diazepam-treated mice, $P < 0.05 versus diazepam and tanshinone I-co-treated mice. Immunoreactivities of phospho-CREB (pCREB) and phosphorylated ERK (pERK) by Western blotting analysis after treatment with tanshinone I and/or MK-801 and/or U0126 (C), and by densitometric analysis (D). Tanshinone I was administered 40 min before, and MK-801 (1 mg·kg−1, i.p.) and/or U0126 (1 nmol, i.c.v.) were administered 30 min before the acquisition trial. The mice were killed immediately after the acquisition trial for the passive avoidance task. Data represent means ± SEM (n= 3 per group). *P < 0.05 versus vehicle controls, #P < 0.05 versus diazepam-treated mice, $P < 0.05 versus MK-801 and tanshinone I-co-treated mice. Con, control; V, vehicle; U, U0126; Tan, tanshinone I. (E) Representative immunoreactivities of pCREB and pERK in the hippocampal tissues of non-trained normal mice (Nor) and trained control mice (Con). Values under the immunoblots represent immunoreactivity ratios versus corresponding individual total protein levels. (F) Effect of tanshinone I alone or combined with MK-801 on spontaneous locomotor behaviour in the open field. The test was conducted as described in Methods. Data represent means ± SEM (n= 10 per group). *P < 0.05 versus vehicle controls.