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

Figure 6.

Figure 6

The effect of tanshinone I on memory impairment induced by diazepam via extracellular signal-regulated kinase (ERK)–cAMP response element binding protein (CREB) signalling. (A) Effect of tanshinone I (1, 2 and 4 mg·kg−1, i.p.) on passive avoidance task latency. Tanshinone I was administered 40 min before, and diazepam 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. (B) Increased passive avoidance task latency induced by tanshinone I (4 mg·kg−1, p.o.) was reversed by U0126 (U, 1 nmol, i.c.v.). Tanshinone I was administered 40 min before, and diazepam and/or U0126 30 min before the acquisition trial. Latency times were determined as described in Methods. Data represent means ± SEM (n= 7 or 8 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 blot analysis in tanshinone I-, diazepam- and/or U0126-treated mice (C), and corresponding densitometric analysis results (D). Tanshinone I was administered 40 min before, and diazepam (1 mg·kg−1, i.p.) and/or U0126 (1 nmol, i.c.v.) 30 min before the acquisition trial for the passive avoidance trial. The mice were killed immediately after the acquisition trial. 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 diazepam 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 passive avoidance test-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 diazepam on spontaneous locomotor behaviour in the open field. The test was conducted as described in Methods. Data represent means ± SEM (n= 10 per group).