Project description:The transcriptional events accompanying synaptogenesis are largely unknown, or have been studied in systems in which synapse formation occurs gradually over time. With a system in which synaptogenesis is synchronized and controllable, molecular or biochemical techniques can be used to examine cellular events across cultures on a wide scale, as synapses develop. Here, we have triggered synaptogenesis in immunopurified subplate neurons by coculturing with cortical feeder layers and have used microarrays to investigate the transcriptional events occuring in this more defined and controllable system. Experiment Overall Design: Affymetrix rat GeneChip microarrays were used to assess whether coculturing induces transcriptional changes in subplate neurons. Subplate synapses develop rapidly following coculturing; an exposure to the feeder layer of only 48 hours is sufficient to detect a significant increase in the density of synapses, and is as effective as longer durations. Within the first few minutes or hours of a cell's response to an exogenous signal, any primary transcriptional events are expected to involve activation of immediate early genes (IEGs), often transcription factors themselves, which may then turn on downstream target response genes encoding factors to be delivered to sites of action, such as synapses. With the aim of searching for such downstream genes, microarrays were performed after 24 hours of coculturing, an intermediate timepoint between the likely phase of IEG transcription and the large wave of synaptogenesis seen between 24 and 48 hours of coculturing. Additional microarrays were also performed after 96 hours of coculturing to assess transcriptional changes that might occur over longer timescales. Five biological replicates of control and cocultured neurons at 24 and 96 hours were used, for a total of 20 microarrays.
Project description:Inflammation is a key component of pathological angiogenesis. Here we induce cornea neovascularisation using sutures placed into the cornea, and sutures are removed to induce a regression phase. We used whole transcriptome microarray to monitor gene expression profies of several genes
Project description:The Norway rat has important impacts on our life. They are amongst the most used research subjects, resulting in ground-breaking advances. At the same time, wild rats live in close association with us, leading to various adverse interactions. In face of this relevance, it is surprising how little is known about their natural behaviour. While recent laboratory studies revealed their complex social skills, little is known about their social behaviour in the wild. An integration of these different scientific approaches is crucial to understand their social life, which will enable us to design more valid research paradigms, develop more effective management strategies, and to provide better welfare standards. Hence, I first summarise the literature on their natural social behaviour. Second, I provide an overview of recent developments concerning their social cognition. Third, I illustrate why an integration of these areas would be beneficial to optimise our interactions with them.
Project description:BackgroundMurine kobuviruses (MuKV) are newly recognized picornaviruses first detected in murine rodents in the USA in 2011. Little information on MuKV epidemiology in murine rodents is available. Therefore, we conducted a survey of the prevalence and genomic characteristics of rat kobuvirus in Guangdong, China.ResultsFecal samples from 223 rats (Rattus norvegicus) were collected from Guangdong and kobuviruses were detected in 12.6% (28) of samples. Phylogenetic analysis based on partial 3D and complete VP1 sequence regions showed that rat kobuvirus obtained in this study were genetically closely related to those of rat/mouse kobuvirus reported in other geographical areas. Two near full-length rat kobuvirus genomes (MM33, GZ85) were acquired and phylogenetic analysis of these revealed that they shared very high nucleotide/amino acids identity with one another (95.4%/99.4%) and a sewage-derived sequence (86.9%/93.5% and 87.5%/93.7%, respectively). Comparison with original Aichivirus A strains, such human kobuvirus, revealed amino acid identity values of approximately 80%.ConclusionOur findings indicate that rat kobuvirus have distinctive genetic characteristics from other Aichivirus A viruses. Additionally, rat kobuvirus may spread via sewage.
Project description:The transcriptional events accompanying synaptogenesis are largely unknown, or have been studied in systems in which synapse formation occurs gradually over time. With a system in which synaptogenesis is synchronized and controllable, molecular or biochemical techniques can be used to examine cellular events across cultures on a wide scale, as synapses develop. Here, we have triggered synaptogenesis in immunopurified subplate neurons by coculturing with cortical feeder layers and have used microarrays to investigate the transcriptional events occuring in this more defined and controllable system. Keywords: treatment type comparison, time course
Project description:Analysis of hormone effects on irradiated LBNF1 rat testes, which contain only somatic cells except for a few type A spermatgogonia. Rats were treated for 2 weeks with either sham treatment (group X), hormonal ablation (GnRH antagonist and the androgen receptor antagonist flutamide, group XAF), testosterone supplementation (GnRH antagonist and testosterone, group XAT), and FSH supplementation ((GnRH antagonist, androgen receptor antagonist, and FSH, group XAFF). Results provide insight into identifying genes in the somatic testis cells regulated by testosterone, LH, or FSH.
Project description:Ecological factors, such as predation, have traditionally been used to explain sociability. However, it is increasingly recognised that individuals within a group do not associate randomly, and that these non-random associations can generate fitness advantages. The majority of the empirical evidence on differentiated associations in group-living mammals, however, comes from a limited number of taxa and we still know very little about their occurrence and characteristics in some highly social species, such as rats (Rattus spp.). Here, using network analysis, we quantified association patterns in four groups of male fancy rats. We found that the associations between rats were not randomly distributed and that most individuals had significantly more preferred/avoided associates than expected by random. We also found that these preferences can be stable over time, and that they were not influenced by individuals' rank position in the dominance hierarchy. Our findings are consistent with work in other mammals, but contrast with the limited evidence available for other rat strains. While further studies in groups with different demographic composition are warranted to confirm our findings, the occurrence of differentiated associations in all male groups of rats have important implications for the management and welfare of captive rat populations.
Project description:Individual differences in behaviors are seen across many species, and investigations have focused on traits linked to aggression, risk taking, emotionality, coping styles, and differences in cognitive systems. The current study investigated whether there were individual differences in proactive interference tasks in rats (Rattus Norvegicus), and tested hypotheses suggesting that these tasks should load onto a single factor and there should be clusters of rats who perform well or poorly on these tasks. The performance of 39 rats was tested across three learning tasks that all involved disengagement from an irrelevant previously learned stimulus to a relevant stimulus: latent inhibition (LI), partial reinforcement extinction effect (PREE), and reversal learning (RL). An exploratory factor analysis revealed the existence of one factor underlying performance. A cluster analysis revealed the existence of sets of rats displaying either weak LI and strong PREE and RL effects, or vice versa. These findings suggest that proactive interference may be based on a single underlying psychological system in rats.