Direct Photocatalytic Methane Oxidation to Formaldehyde by N Doping Co-Decorated Mixed Crystal TiO2.

In this paper, N-doped TiO2 mixed crystals are prepared via direct calcination of TiN for highly selective oxidation of CH4 to HCHO at room temperature. The structures of the prepared TiO2 samples are characterized to be N-doped TiO2 of anatase and rutile mixed crystals. The crystal structures of TiO2 samples are determined by XRD spectra and Raman spectra, while N doping is demonstrated by TEM mapping, ONH inorganic element analysis, and high-resolution XPS results. Significantly, the production rate of HCHO is as high as 23.5 mmol·g-1·h-1 with a selectivity over 90%. Mechanism studies reveal that H2O is the main oxygen source and acts through the formation of ·OH. DFT calculations indicate that the construction of a mixed crystal structure and N-doping modification mainly act by increasing the adsorption capacity of H2O. An efficient photocatalyst was prepared by us to convert CH4 to HCHO with high yield and selectivity, greatly promoting the development of the photocatalytic CH4 conversion study.

[Deficiency of cathepsin K improves ischemic angiogenesis in high-fat diet fed mice].

The present study aims to investigate the effect of cathepsin K (CatK) on ischemic angiogenesis in high-fat diet fed mice. The mice were subjected to unilateral hindlimb ischemic surgery, and the ischemic blood flow was measured with a laser Doppler blood flow imager. Immunohistochemical staining was used to observe the quantity of new capillaries in the ischemic lower extremity, and Western blot was used to detect the expression of insulin receptor substrate-1 (IRS-1), p-Akt, Akt and vascular endothelial growth factor (VEGF). Firstly, the effect of high-fat diet on ischemic angiogenesis was observed in wild-type mice, which were randomly divided into control group and high-fat diet group and were fed with normal diet or 60% high-fat diet respectively for 16 weeks. The results showed the body weight and the plasma CatK concentration of the high-fat diet group was significantly increased compared with the control group (P < 0.05), and the blood flow recovery of the high-fat diet group was significantly lower than control group (P < 0.05). Then, wild-type and CatK knock out (CatK-/-) mice were both fed with high-fat diet to further observe the effect and mechanism of CatK on ischemic angiogenesis under high-fat diet. The results showed that the blood flow recovery in the CatK-/- group was significantly greater than the wild-type group, and the number of CD31 positive cells was significantly increased (P < 0.05). At the same time, the protein expression levels of IRS-1, p-Akt and VEGF in the ischemic skeletal muscle were significantly increased in the CatK-/- group compared with the wild-type group (P < 0.05). These results suggest that the deficiency of CatK improves ischemic angiogenesis in high-fat diet fed mice through IRS-1-Akt-VEGF signaling pathway.

Use of 3D Echocardiography Facilitates Analysis of Thrombolytic Efficacy in Patients With Persistent Atrial Fibrillation.

ABSTRACT: This study seeks to identify the anticoagulant efficacy of rivaroxaban treatment on thrombi detected using echocardiography of the left atrial appendage in 275 patients with persistent atrial fibrillation. During follow-up after 9-24 weeks of rivaroxaban treatment, patients were divided into "effective group" (n = 143) and "ineffective group" (n = 132) according to the thrombolytic effect of the drug. Left atrial diameter (LAD), left atrial ejection fraction (LAEF), left ventricular ejection fraction (LVEF), mean diameter of left atrial appendage (LAAD mean ), angle between left atrial appendage and left atrium (LAA-A), velocity of blood flow in left atrial appendage (LAA-v), and thrombus size were compared before and after drug administration. Following treatment, LAEF, LVEF, and LAA-v values were greater and LAD and LAAD mean values were lower in the effective ( P < 0.05). Logistic regression analysis showed significant correlations of LAD, LAEF, LVEF, LAA-A, and LAA-v with anticoagulant efficacy ( P < 0.05). The efficacy of rivaroxaban in treatment of left atrial auricular thrombosis in patients with persistent AF was correlated with LAD, LAEF, LVEF, LAA-A, and LAA-v. Multivariate logistic regression analysis further revealed LAEF [odds ratio (OR) 1.7, 95% confidence interval (CI), 0.45-16.9, P = 0.008], 3D-EF (OR 6.4, 95% CI, 1.06-16.9, P = 0.039) and left ventricular global longitudinal strain (OR 18.0, 95% CI, 1.38-35.68, P = 0.028) as factors related to left atrial appendage thrombus. Echocardiography with global longitudinal strain assessment could be effectively utilized to evaluate the functional parameters of LAA and thus aid in predicting the safety of rivaroxaban as an anticoagulation agent.

The assembled and annotated genome of the masked palm civet (Paguma larvata).

BACKGROUND: The masked palm civet (Paguma larvata) acts as an intermediate host of severe acute respiratory syndrome coronavirus (SARS-CoV), which caused SARS, and transfered this virus from bats to humans. Additionally, P. larvata has the potential to carry a variety of zoonotic viruses that may threaten human health. However, genome resources for P. larvata have not been reported to date. FINDINGS: A chromosome-level genome assembly of P. larvata was generated using PacBio sequencing, Illumina sequencing, and Hi-C technology. The genome assembly was 2.44 Gb in size, of which 95.32% could be grouped into 22 pseudochromosomes, with contig N50 and scaffold N50 values of 12.97 Mb and 111.81 Mb, respectively. A total of 21,582 protein-coding genes were predicted, and 95.20% of the predicted genes were functionally annotated. Phylogenetic analysis of 19 animal species confirmed the close genetic relationship between P. larvata and species belonging to the Felidae family. Gene family clustering revealed 119 unique, 243 significantly expanded, and 58 significantly contracted genes in the P. larvata genome. We identified 971 positively selected genes in P. larvata, and one known human viral receptor gene PDGFRA is positively selected in P. larvata, which is required for human cytomegalovirus infection. CONCLUSIONS: This high-quality genome assembly provides a valuable genomic resource for exploring virus-host interactions. It will also provide a reliable reference for studying the genetic bases of the morphologic characteristics, adaptive evolution, and evolutionary history of this species.

[Effects of Cathepsin K on spatial learning and memory in rats].

OBJECTIVE: To investigate the effects of Cathepsin K(CatK) on spatial learning and memory in rat hippocampus and its mechanisms. METHODS: Twenty male SD rats were randomly divided into Control group and CatK inhibitor group(CatKⅡ group), which were microinjected with Cathepsin K specific inhibitor(0.5 µg/µl) and artificial cerebrospinal fluid in hippocampal DG area respectively with 5 days. The cultured hippocampal neuron cells were divided into control group (CON group), negative control group(NC group), siRNA interference group(siCatK group). Three re-wells were set for each group, and samples were collected 18～20 h after siRNA transfection. Morris water maze was used to evaluate spatial learning and memory function of rats. Meanwhile, dynamic changes of glutamate(Glu) content in extracellular fluid of DG region during learning and memory were observed by microdialysis and high performance liquid chromatography in conscious rats. Western blot was used to detect CatK-mediated Notch1 activation and other signal molecules. RESULTS: Animal experiments showed that compared with the control group, the spatial learning and memory ability were decreased significantly in CatKII group, and the hippocampus protein expressions of c-Notch1, p-Akt, p-CREB and BDNF were also decreased significantly(P＜0.05); the levels of Glu in DG area of control group and CatK II group were increased significantly with Morris water maze training days, but the increase of CatK II group was significantly weaker than that of control group(P＜ 0.05). The results of cell experiment showed that the expressions of CatK, c-Notch1, p-CREB and BDNF in siCatK group were significantly lower than other groups (P＜0.05). CONCLUSION: CatK can affect the spatial learning and memory function of rats by activating Notch1 and its memory related signal protein in hippocampus.

Combined proteomics and transcriptomics reveal the genetic basis underlying the differentiation of skin appendages and immunity in pangolin.

Pangolin (Mains javanica) is an interesting endangered mammal with special morphological characteristics. Here, we applied proteomics and transcriptomics to explore the differentiation of pangolin skin appendages at two developmental stages and to compare gene expression profiles between abdomen hair and dorsal scale tissues. We identified 4,311 genes and 91 proteins differentially expressed between scale-type and hair-type tissue, of which 6 genes were shared by the transcriptome and proteome. Differentiation altered the abundance of hundreds of proteins and mRNA in the two types of skin appendages, many of which are involved in keratinocyte differentiation, epidermal cell differentiation, and multicellular organism development based on GO enrichment analysis, and FoxO, MAPK, and p53 signalling pathways based on KEGG enrichment analysis. DEGs in scale-type tissues were also significantly enriched in immune-related terms and pathways compared with that in hair-type tissues. Thus, we propose that pangolins have a normal skin innate immune system. Compared with the abdomen, the back skin of pangolins had more genes involved in the regulation of immune function, which may be an adaptive adjustment for the vulnerability of scaly skin to infection and injury. This investigation provides a scientific basis for the study of development and immunity of pangolin skin, which may be helpful in the protection of wild pangolin in China.

Rational Design of Two-Dimensional Transition Metal Carbide/Nitride (MXene) Hybrids and Nanocomposites for Catalytic Energy Storage and Conversion.

Electro-, photo-, and photoelectrocatalysis play a critical role toward the realization of a sustainable energy economy. They facilitate numerous redox reactions in energy storage and conversion systems, enabling the production of chemical feedstock and clean fuels from abundant resources like water, carbon dioxide, and nitrogen. One major obstacle for their large-scale implementation is the scarcity of cost-effective, durable, and efficient catalysts. A family of two-dimensional transition metal carbides, nitrides, and carbonitrides (MXenes) has recently emerged as promising earth-abundant candidates for large-area catalytic energy storage and conversion due to their unique properties of hydrophilicity, high metallic conductivity, and ease of production by solution processing. To take full advantage of these desirable properties, MXenes have been combined with other materials to form MXene hybrids with significantly enhanced catalytic performances beyond the sum of their individual components. MXene hybridization tunes the electronic structure toward optimal binding of redox active species to improve intrinsic activity while increasing the density and accessibility of active sites. This review outlines recent strategies in the design of MXene hybrids for industrially relevant electrocatalytic, photocatalytic, and photoelectrocatalytic applications such as water splitting, metal-air/sulfur batteries, carbon dioxide reduction, and nitrogen reduction. By clarifying the roles of individual material components in the MXene hybrids, we provide design strategies to synergistically couple MXenes with associated materials for highly efficient and durable catalytic applications. We conclude by highlighting key gaps in the current understanding of MXene hybrids to guide future MXene hybrid designs in catalytic energy storage and conversion applications.

Transcriptome analysis reveals the genetic basis underlying the development of skin appendages and immunity in hedgehog (Atelerix albiventris).

The expression of hair features is an evolutionary adaptation resulting from interactions between many organisms and their environment. Elucidation of the mechanisms that underlie the expression of such traits is a topic in evolutionary biology research. Therefore, we assessed the de novo transcriptome of Atelerix albiventris at three developmental stages and compared gene expression profiles between abdomen hair and dorsal spine tissues. We identified 328,576 unigenes in our transcriptome, among which 4,435 were differentially expressed between hair- and spine-type tissues. Dorsal and abdomen skin tissues 5 days after birth were compared and the resulting DEGs were mainly enriched in keratin filament, epithelium cell differentiation, and epidermis development based on GO enrichment analysis, and tight junction, p53, and cell cycle signaling pathways based on KEGG enrichment analysis. MBP8, SFN, Wnt1 and KRT1 gene may involve in the development of hedgehog skin and its appendages. Strikingly, DEGs in hair-type tissues were also significantly enriched in immune-related terms and pathways with hair-type tissues exhibiting more upregulated immune genes than spine-type tissues. Our study provided a list of potential genes involved in skin appendage development and differentiation in A. albiventris, and the candidate genes provided valuable information for further studies of skin appendages.

Synthesis and antibacterial activity of a series novel 5,7-diisoprenyloxyflavone derivatives

In the present study, a series of novel 5,7-diisoprenyloxyflavone derivatives were designed, synthesized, and evaluated for their antibacterial activity. Most of these compounds displayed significant antibacterial effects against Gram-positive bacteria, especially against strains of multidrug-resistant clinical isolates. Compounds 4c, 4g, 4i, 4j, 4k, 4l, 4n, 4q and 4t showed high levels of antimicrobial activity against Staphylococcus aureus RN4220 with minimum inhibitory concentrations of 4.0-20 µM. Compound 4k showed the most potent activity among these compounds against all multidrug-resistant clinical isolates tested. Unfortunately, none of the compounds were active against Gram-negative bacteria at the doses of 24-164 µM.

Genome Sequence of Morganella morganii DG56-16, Isolated from Shinisaurus crocodilurus.

The complete genome sequence of Morganella morganii DG56-16 was sequenced. This strain was isolated from the liver of a dead crocodile lizard (Shinisaurus crocodilurus). The genome size was 3.9 Mb, with a G+C content of 50.9%.

SMRT sequencing of the full-length transcriptome of the Sunda pangolin (Manis javanica).

It is widely known that transcriptional diversity contributes greatly to biological regulation in eukaryotes. With the development of next-generation sequencing (NGS) technologies, several studies on RNA sequencing have considerably improved our understanding of transcriptome complexity. However, obtaining full-length (FL) transcripts remains a considerable challenge because of difficulties in short read-based assembly. In the present study, single-molecule real-time (SMRT) sequencing and NGS were combined to generate the complete and FL transcriptome of Manis javanica. The results provide a comprehensive set of reference transcripts and hence contribute to the improved annotation of the M. javanica genome. We obtained 45,530 high-confidence transcripts from 19,109 genic loci, of which 8014 genes have not yet been annotated within the M. javanica genome. Furthermore, we revealed 8824 long-chain noncoding RNAs (lncRNAs). A total of 30,199 alternative splicing (AS) and 11,184 alternative polyadenylation (APA) events were identified in the sequencing data. The structure and expression level of 59 digestive enzyme genes, including 13 carbohydrase genes, 28 lipase genes and 18 protease genes, were analyzed, which might provide original data for further research on M. javanica.

The Fecal Metagenomics of Malayan Pangolins Identifies an Extensive Adaptation to Myrmecophagy.

The characteristics of flora in the intestine of an animal, including the number and abundance of different microbial species and their functions, are closely related to the diets of the animal and affect the physical condition of the host. The Malayan pangolin (Manis javanica) is an endangered species that specializes in myrmecophagy. Analyzing the microbiome in the intestine of the pangolin is imperative to protect this species. By sequencing the metagenomes of the feces of four pangolins, we constructed a non-redundant catalog of 211,868 genes representing 1,811 metagenomic species. Taxonomic annotation revealed that Bacteroidetes (49.9%), Proteobacteria (32.2%), and Firmicutes (12.6%) are the three main phyla. The annotation of gene functions identified 5,044 genes from 88 different glycoside hydrolase (GH) families in the Carbohydrate-Active enZYmes database and 114 gene modules related to chitin-degrading enzymes, corresponding to the catalytic domains of GH18 family enzymes, containing chitinase genes of classes III and V in the dataset. Fourteen gene modules corresponded to the catalytic domains of GH19 family enzymes, containing chitinase genes of classes I, II, and IV. These genes were found in 37 species belonging to four phyla: Bacteroidetes, Cyanobacteria, Firmicutes, and Proteobacteria. Moreover, when the metabolic pathways of these genes were summarized, 41,711 genes were associated with 147 unique KEGG metabolic pathways, and these genes were assigned to two Gene Ontology terms: metabolic process and catalytic activity. We also found several species that likely play roles in the digestion of cellulose and may be able to degrade chitin, including Enterobacter cloacae, Lactococcus lactis, Chitinimonas koreensis, and Chitinophaga pinensis. In addition, we identified some intestinal microflora and genes related to diseases in pangolins. Twenty-seven species were identified by STAMP analysis as differentially abundant in healthy and diseased animals: 20 species, including Cellulosilyticum lentocellum and Lactobacillus reuteri, were more abundant in healthy pangolins, while seven species, including Odoribacter splanchnicus, Marinilabilia salmonicolor, Xanthomonas citri, Xanthomonas vasicola, Oxalobacter formigenes, Prolixibacter bellariivorans, and Clostridium bolteae, were more abundant in diseased pangolins. These results will support the efforts to conserve pangolins.

Complete Genome Sequence of Austwickia chelonae LK16-18, Isolated from Crocodile Lizards.

Austwickia chelonae, a species of Actinobacteria, is one of the pathogens that cause dermatophilosis in animals. Here, we report the complete genome sequence of Austwickia chelonae LK16-18, which was isolated from cutaneous granulomas in crocodile lizards.

Acidic mammalian chitinase gene is highly expressed in the special oxyntic glands of Manis javanica.

The Malayan pangolin (Manis javanica) is a mammal that feeds primarily on ants and termites, which contain the energy-rich carbohydrate chitin. Chitin is digestible by endogenous enzymes of the typical mammalian gastrointestinal tract, especially the acidic mammalian chitinase (AMCase). The objective of this research was to determine whether AMCase activity is expressed in the stomach of M. javanica. The stomach tissues were divided into three parts: the gastric sack, the oxyntic glands, and the pyloric musculature, which were assayed by conventional RT-PCR, quantitative reverse transcriptase-coupled PCR (qPCR) and western blot. Information regarding 3D structural models of AMCase was also obtained. In conclusion, acidic mammalian chitinase is highly expressed in the oxyntic glands of the M. javanica species.

Luteolin Inhibits Tumorigenesis and Induces Apoptosis of Non-Small Cell Lung Cancer Cells via Regulation of MicroRNA-34a-5p.

Luteolin (LTL) exerts remarkable tumor suppressive activity on various types of cancers, including non-small cell lung cancer (NSCLC). However, it is not completely understood whether the mechanism of its action against NSCLC is related to microRNAs (miRNAs). In the present study, we investigated the anti-tumor effects of LTL on NSCLC in vitro and in vivo. The results revealed that LTL could inhibit cell proliferation and induce apoptosis in both A549 and H460 cells. In a H460 xenograft tumor model of nude mice, LTL significantly suppressed tumor growth, inhibited cell proliferation, and induced apoptosis. miRNA microarray and quantitative PCR (qPCR) analysis indicated that miR-34a-5p was dramatically upregulated upon LTL treatment in tumor tissues. Furthermore, MDM4 was proved to be a direct target of miR-34a-5p by luciferase reporter gene assay. LTL treatment was associated with increased p53 and p21 protein expressions and decreased MDM4 protein expression in both NSCLC cells and tumor tissues. When miR-34a-5p was inhibited in vitro, the protein expressions of Bcl-2 and MDM4 were recovered, while that of p53, p21, and Bax were attenuated. Moreover, caspase-3 and caspase-9 activation induced by LHL treatment in vitro were also suppressed by miR-34a-5p inhibition. Overall, LTL could inhibit tumorigenesis and induce apoptosis of NSCLC cells by upregulation of miR-34a-5p via targeting MDM4. These findings provide novel insight into the molecular functions of LTL that suggest its potential as a therapeutic agent for human NSCLC.

Diets Alter the Gut Microbiome of Crocodile Lizards.

The crocodile lizard is a critically endangered reptile, and serious diseases have been found in this species in recent years, especially in captive lizards. Whether these diseases are caused by changes in the gut microbiota and the effect of captivity on disease remains to be determined. Here, we examined the relationship between the gut microbiota and diet and disease by comparing the fecal microbiota of wild lizards with those of sick and healthy lizards in captivity. The gut microbiota in wild crocodile lizards was consistently dominated by Proteobacteria (∼56.4%) and Bacteroidetes (∼19.1%). However, the abundance of Firmicutes (∼2.6%) in the intestine of the wild crocodile lizards was distinctly lower than that in other vertebrates. In addition, the wild samples from Guangdong Luokeng Shinisaurus crocodilurus National Nature Reserve also had a high abundance of Deinococcus-Thermus while the wild samples from Guangxi Daguishan Crocodile Lizard National Nature Reserve had a high abundance of Tenericutes. The gut microbial community in loach-fed crocodile lizards was significantly different from the gut microbial community in the earthworm-fed and wild lizards. In addition, significant differences in specific bacteria were detected among groups. Notably, in the gut microbiota, the captive lizards fed earthworms resulted in enrichment of Fusobacterium, and the captive lizards fed loaches had higher abundances of Elizabethkingia, Halomonas, Morganella, and Salmonella, all of which are pathogens or opportunistic pathogens in human or other animals. However, there is no sufficient evidence that the gut microbiota contributes to either disease A or disease B. These results provide a reference for the conservation of endangered crocodile lizards and the first insight into the relationship between disease and the gut microbiota in lizards.

Transcriptomic analysis identifies genes and pathways related to myrmecophagy in the Malayan pangolin (Manis javanica).

The Malayan pangolin (Manis javanica) is an unusual, scale-covered, toothless mammal that specializes in myrmecophagy. Due to their threatened status and continuing decline in the wild, concerted efforts have been made to conserve and rescue this species in captivity in China. Maintaining this species in captivity is a significant challenge, partly because little is known of the molecular mechanisms of its digestive system. Here, the first large-scale sequencing analyses of the salivary gland, liver and small intestine transcriptomes of an adult M. javanica genome were performed, and the results were compared with published liver transcriptome profiles for a pregnant M. javanica female. A total of 24,452 transcripts were obtained, among which 22,538 were annotated on the basis of seven databases. In addition, 3,373 new genes were predicted, of which 1,459 were annotated. Several pathways were found to be involved in myrmecophagy, including olfactory transduction, amino sugar and nucleotide sugar metabolism, lipid metabolism, and terpenoid and polyketide metabolism pathways. Many of the annotated transcripts were involved in digestive functions: 997 transcripts were related to sensory perception, 129 were related to digestive enzyme gene families, and 199 were related to molecular transporters. One transcript for an acidic mammalian chitinase was found in the annotated data, and this might be closely related to the unique digestive function of pangolins. These pathways and transcripts are involved in specialization processes related to myrmecophagy (a form of insectivory) and carbohydrate, protein and lipid digestive pathways, probably reflecting adaptations to myrmecophagy. Our study is the first to investigate the molecular mechanisms underlying myrmecophagy in M. javanica, and we hope that our results may play a role in the conservation of this species.

Copper-Based Coordination Polymer Nanostructure for Visible Light Photocatalysis.

An air-stable copper-phenylacetylide nanobelt is synthesized and applied in organic pollutants elimination under visible light. Its versatile activity and reusability indicate it is a promising photocatalyst, arising from a band gap of 2.3 eV and the energetically favored electron transfer processes. The tunable structures and properties endow copper-based coordination polymers a prosperous prospect.

Fucosterol, a sterol extracted from Sargassum fusiforme, shows antidepressant and anticonvulsant effects.

We previously showed that extracts of Sargassum fusiforme significantly reduce immobility time in the forced swim test and tail suspension test, suggesting that these extracts possess antidepressant-like effects. Here, fucosterol extracted from S. fusiforme was evaluated for antidepressant and anticonvulsant activities in mice. Fucosterol (10, 20, 30 and 40mg/kg) significantly shortened immobility time in the forced swim test and tail suspension test for30min after treatment but had no effect on locomotor activity in the open field test. Fucosterol significantly increased serotonin, norepinephrine and the metabolite 5-hydroxyindoleacetic acid in mouse brain, suggesting that the effects of fucosterol may be mediated through these neurotransmitters. As assessed using maximal electroshock, fucosterol (20, 40, 100mg/kg) possessed anticonvulsant activity, whereas rotarod toxicity test results indicated that fucosterol did not induce neurotoxicity at the same dose levels in mice. Thus, fucosterol may be a useful antidepressant adjunct candidate for treating depression in patients with epilepsy. A significant increase in hippocampal brain-derived neurotrophic factor (BDNF) levels was found in the fucosterol 20mg/kg group (P<0.05). Our findings suggested that fucosterol may possess an antidepressant-like effect, which may be mediated by increasing central BDNF levels.

[Effect of 5-HT1A receptors in the hippocampal DG on active avoidance learning in rats].

OBJECTIVE: To investigate the effects of serotonin (5-HTIA) receptors in the hippocampal dentate gyrus (DG) on active avoidance learning in rats. METHODS: Totally 36 SD rats were randomly divided into control group, antagonist group and agonist group(n = 12). Active avoidance learning ability of rats was assessed by the shuttle box. The extracellular concentrations of 5-HT in the DG during active avoidance conditioned reflex were measured by microdialysis and high performance liquid chromatography (HPLC) techniques. Then the antagonist (WAY-100635) or agonist (8-OH-DPAT) of the 5-HT1A receptors were microinjected into the DG region, and the active avoidance learning was measured. RESULTS: (1) During the active avoidance learning, the concentration of 5-HT in the hippocampal DG was significantly increased in the extinction but not establishment in the conditioned reflex, which reached 164.90% ± 26.07% (P <0.05) of basal level. (2) The microinjection of WAY-100635 (an antagonist of 5-HT1A receptor) into the DG did not significantly affect the active avoidance learning. (3) The microinjection of 8-OH-DPAT(an agonist of 5-HT1A receptor) into the DG significantly facilitated the establishment process and inhibited the extinction process during active avoidance conditioned reflex. CONCLUSION: The data suggest that activation of 5-HT1A receptors in hipocampal DG may facilitate active avoidance learning and memory in rats.