The effect of visually evoked innate fear on reward-associated conditional response and reversal learning in mice.

The response to visually evoked innate fear is essential for survival and impacts the cognition and behavior of animals to threats in the environment. However, contradictory findings of the interaction of fear and executive behaviors were reported by previous studies. To address this question, the present study investigated the effect of looming stimuli-driven visually innate fear on reward-associated conditioned response and reversal learning in mice with low or high motivation for sucrose. The mice with low motivation exposed to looming stimuli displayed reduced efficiency in the test of conditional response in the fixed ratio 1 schedule and impaired executive motivation as tested in the progressive ratio schedule of reinforcement. However, the high motivated mice exposed to looming stimuli showed an unaffected conditional response but an increased executive motivation. In the reversal learning program, looming stimuli at the middle stage caused deficits in cognitive flexibility in the mice with low and high motivation. Therefore, these results illuminate the impact of visually evoked innate fear on conditional response and reversal learning and further show that the impacts are relevant to internal motivation and external fear stimuli.

Behavioral sensitization induced by methamphetamine causes differential alterations in gene expression and histone acetylation of the prefrontal cortex in rats.

BACKGROUND: Methamphetamine (METH) is one of the most widely abused illicit substances worldwide; unfortunately, its addiction mechanism remains unclear. Based on accumulating evidence, changes in gene expression and chromatin modifications might be related to the persistent effects of METH on the brain. In the present study, we took advantage of METH-induced behavioral sensitization as an animal model that reflects some aspects of drug addiction and examined the changes in gene expression and histone acetylation in the prefrontal cortex (PFC) of adult rats. METHODS: We conducted mRNA microarray and chromatin immunoprecipitation (ChIP) coupled to DNA microarray (ChIP-chip) analyses to screen and identify changes in transcript levels and histone acetylation patterns. Functional enrichment analyses, including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, were performed to analyze the differentially expressed genes. We then further identified alterations in ANP32A (acidic leucine-rich nuclear phosphoprotein-32A) and POU3F2 (POU domain, class 3, transcription factor 2) using qPCR and ChIP-PCR assays. RESULTS: In the rat model of METH-induced behavioral sensitization, METH challenge caused 275 differentially expressed genes and a number of hyperacetylated genes (821 genes with H3 acetylation and 10 genes with H4 acetylation). Based on mRNA microarray and GO and KEGG enrichment analyses, 24 genes may be involved in METH-induced behavioral sensitization, and 7 genes were confirmed using qPCR. We further examined the alterations in the levels of the ANP32A and POU3F2 transcripts and histone acetylation at different periods of METH-induced behavioral sensitization. H4 hyperacetylation contributed to the increased levels of ANP32A mRNA and H3/H4 hyperacetylation contributed to the increased levels of POU3F2 mRNA induced by METH challenge-induced behavioral sensitization, but not by acute METH exposure. CONCLUSIONS: The present results revealed alterations in transcription and histone acetylation in the rat PFC by METH exposure and provided evidence that modifications of histone acetylation contributed to the alterations in gene expression caused by METH-induced behavioral sensitization.

Bound PAHs in Sediment and Related Environmental Significance.

Extractable polycyclic aromatic hydrocarbons (EPAHs) and bound PAHs (BPAHs) were measured in a sediment core using conventional Soxhlet extraction and a more astringent extraction method, with the objectives of determining the influence of BPAHs on the historical reconstruction of PAHs and exploring the formation of BPAHs and long-term behaviors of PAHs in sediment. The results indicated that the formation of BPAHs was clearly sediment-depth and molecular-size dependent. BPAHs represents an important portion of PAHs in sediment and cannot be extracted by conventional Soxhlet extraction. This suggests that the previously developed vertical profile of PAHs is not the real chronology of PAHs and the plausible interpretation derived from the sedimentary records of PAHs needs reexamination. Based on the previous findings, a biphase model was proposed and the formation of BPAHs was predicted. Due to the different nature of geosorbents in sediment, redistribution of PAHs among these geosorbents logically leads to the formation of BPAHs and is kinetically favorable for smaller molecular PAHs. This is consistent with the obtained results. Many factors may influence the formation of BPAHs, such as the physicochemical structure of sediment and environmental conditions. There is still a long way to reveal the thermodynamical characteristics in action during the formation of BPAHs.

[High-resolution Distribution Characteristics of Phosphorous, Iron and Sulfur Across the Sediment-Water Interface of Aha Reservoir].

In situ two-dimension, high-resolution distribution of phosphorus(P), iron(Fe), sulfur(S) from the sediment-water interface was investigated in different areas of Aha Reservoir, a typical sub-deep water lake, using diffusive gradients in thin films(DGT) technique, combining with water chemistry and sedimentary phosphorus speciation analysis, aimed to discuss the distribution and control factors of P-Fe-S in sediments. DGT-P ranged from 0.00 mg·L-1 to 0.43 mg·L-1. DGT-Fe rangd from 0.00 mg·L-1 to 2.83 mg·L-1. DGT-S ranged from 0.00 mg·L-1 to 0.10 mg·L-1. There was no significant correlation among the concentrations of P, Fe, S in the sediment pore water of Aha Reservoir, which is markedly different from the results of previous studies. We hypothesize that the high ratios of Fe/P and Fe/S induced the direct reaction of surplus Fe(Ⅲ) with S2-, yielding FeS and/or FeS2, while P was firmly fixed in sediments by Fe(Ⅲ). NaOH-SRP(ranging between 192 and 604 mg·kg-1) and BD-P(ranging between 143 and 524 mg·kg-1) were the two major fractions of P in sediments. Since the environment for the bottom layer of water in Aha Reservoir is anoxic, the geochemical cycle of Fe and S potentially has a massive impact on the activation and migration of sedimentary P.

Contamination trends of trace metals and coupling with algal productivity in sediment cores in Pearl River Delta, South China.

Several sediment cores from the Pearl River Delta were collected to investigate the relationship of trace metal contamination with algae-derived organic matter in the last 50 years. Trace metals were analyzed with ICP-MS, and algal organic matter (AOM) was measured with Rock-Eval pyrolysis. It was found that Cu, Zn, Ag, Cd, and As were elevated in the last three decades from three reservoirs, while all of the target metals showed no significant enrichment in estuarine sediment cores. Cu, Cr, Co, Cd, Zn, Ag, Ni, As, and Mn normalized to Ti were strongly associated with AOM in the sediments of eutrophic reservoirs, suggesting that AOM played an important role in controlling the accumulation of trace metals. Principal component analysis (PCA) and enrichment factor (EF) were also used to assess the enrichment of trace metals. The above result indicated that the sedimentary process of As, Cd, Cu, Zn, Ni, Cr, Co, Ag, and Mn was significantly affected or/and controlled by primary productivity in eutrophic, non-point polluted reservoirs.

[Characteristics of sediment heavy metal pollution in three water supply reservoirs in Huizhou, Guangdong Province of South China].

To understand the present status of the heavy metal (Cr, Cu, Zn, Cd, Pb and Hg) pollution of the sediments in water supply reservoirs in Huizhou, sediment cores were sampled from three representative reservoirs. The heavy metal concentrations were analyzed by ICP-MS, and the pollution status was assessed by geo-accumulation index (Igeo) and potential ecological risk index (RI). In the meantime, the possible sources of the heavy metals were analyzed by the principal component analysis (PCA). In the sediments of the three reservoirs, the test heavy metals had different vertical distribution, some had less change, the others decreased or increased with depth, and the distribution patterns differed with the reservoirs. According to the Igeo, the sediments in the reservoirs were seriously polluted by Zn and Pb (Zn: 49.98-640.29 mg x kg(-1); Pb: 21.94-300.66 mg x kg(-1)), reaching slight to high pollution, and the middle or bottom part of the sediments was slightly polluted by Cu (16.85-45.46 mg x kg(-1)). On the whole, the sediments were not polluted by Cr, Cd and Hg. According to the RI and the potential ecological risk coefficient [Er(i)], the sediments in the three reservoirs were under low potential ecological risk. Based on the PCA and relevant information, the human activities such as mining and smelting, urbanization, and agriculture and forestry had great contribution to the heavy metal pollution. The Zn and Pb pollution mainly originated from mining and smelting, Pb pollution also came from motor vehicle exhaust emission and domestic wastes, and Cu pollution mainly derived from agriculture and forestry.

[Distribution and pollution characteristics of nutrients and heavy metals in sediments of Hedi Reservoir].

Core sediments were collected from the riverine, transition and lacustrine zones of Hedi Reservoir in southern China to investigate the spatial distributions of nutrients and heavy metals and assess the potential ecological risk of heavy metals. The total nitrogen (TN) contents of the sediments at three sampling sites are between 2.314-2.427 mg x g(-1), while total phosphorus (TP) contents range from 0.591 mg x g(-1) to 0.760 mg x g(-1), TN contents of the surface sediments increase from the riverine zone to the lacustrine zone, but the TP content in the transition zone is higher than that in the other two sites (riverine zone and lacustrine zone). The mean contents of heavy metals are: 31.094, 46.85, 75.615, 385.739, 0.624 and 0.171 mg x kg(-1) respectively, except Cr, the contents of heavy metals in sediment of lacustrine zone are higher than the sediment of transition zone. In all core sediments, the contents of nutrients and heavy metals decrease from the surface to the bottom of core sediments. Inorganic phosphorus (IP) is the dominant fraction of phosphorus in the sediment and the NaOH-P is the main forms of inorganic phosphorus. The potential ecological risk assessed by using of the highest environmental background values before industrialization as the reference indicates that each single heavy metal only causes slightly pollution, but two heavy metals (Cd and Hg) cause heavy pollution based on the soil environmental background values of Guangdong province. In spite of the slight difference between two kinds of risk assessment, all demonstrated that Cd and Hg resulted in more serious pollution than the other metals and these two metals contributed most to the RI values.

[The influence of temperature on the protein expression of human lung cancer cell line A549].

The study on proteome of human cancer is helpful to explain its pathogenesis and make good effect on its prevention and cure. We compared the 2-DE maps of whole proteins of human lung cancer line A549 at 37 degrees C, 42 degrees C and 45 degrees C for the purpose of studying the expression of its heat shock proteins. Three temperature-sensitive differential spots were obtained and named as P1, P2, P3, respectively. Analyzed by MALDI-TOF-MS and Peptident software searched in the SWISS-PROT database, the three differential proteins were elementarily identified. P1 matches with two proteins belong to the Aldo-keto reductase family, P2 may be a new protein and P3 is Zinc finger protein 11A.