Rodent Models Of Human Disease Research Articles

Discovery of NXT-10796, an orally active, intestinally restricted EP4 agonist prodrug for the treatment of inflammatory bowel disease

A property-focused optimization strategy was employed to modify the carboxylic acid head group of a class of EP4 agonists in order to minimize its absorption upon oral administration. The resulting oxalic acid monohydrazide-derived carboxylate isostere demonstrated utility as a class of prodrug showing colon-targeted delivery of parent agonist 2, with minimal exposure observed in the plasma. Oral administration of NXT-10796 demonstrated tissue specific activation of the EP4 receptor through modulation of immune genes in the colon, without modulation of EP4 driven biomarkers in the plasma compartment. Although further in depth understanding of the conversion of NXT-10796 is required for further assessment of the developability of this series of prodrugs, using NXT-10796 as a tool molecule has allowed us to confirm that tissue-specific modulation of an EP4-modulated gene signature is possible, which allows for further evaluation of this therapeutic modality in rodent models of human disease.

Synthesis and formulation of [64Cu]Cu-PTSM for PET perfusion imaging in small animal models

PurposeThe [64Cu]Cu-PTSM radiopharmaceutical, pyruvaldehyde bis(N4-methylthiosemicarbazonato)copper(II), is suitable for use in microPET and autoradiographic imaging to assess regional tissue perfusion in small animal models. We report here an approach to synthesis and formulation of the [64Cu]Cu-PTSM radiopharmaceutical at the high concentrations required for use in imaging with rodent models of human disease. MethodsThe [64Cu]Cu-PTSM radiopharmaceutical was prepared at small volumes by addition of the H2PTSM ligand to acetate-buffered [64Cu]copper chloride, followed by solid phase extraction to isolate and purify the product, which was then recovered and formulated in 2-mL normal saline containing 5% ethanol and 5% propylene glycol. Results. The [64Cu]Cu-PTSM radiopharmaceutical has been produced over the range of 0.41–1.85 GBq (11–50 mCi) [64Cu]Cu-PTSM in the 2.0-mL final product volume. Radiochemical purity of the [64Cu]Cu-PTSM radiopharmaceutical product averaged 99.8 ± 0.4% (n = 64), with the final formulated product produced at an 83 ± 5% radiochemical yield. ConclusionsThe approach to [64Cu]Cu-PTSM synthesis and formulation has proven to be reliable and robust, supporting radiopharmaceutical delivery at the high concentrations required for PET studies in mouse and other rodent models.

Pharmacological Characterization of Orofacial Nociception in Female Rats Following Nitroglycerin Administration.

Rodent models of human disease can be valuable for understanding the mechanisms of a disease and for identifying novel therapies. However, it is critical that these models be vetted prior to committing resources to developing novel therapeutics. Failure to confirm the model can lead to significant losses in time and resources. One model used for migraine headache is to administer nitroglycerin to rodents. Nitroglycerin is known to produce migraine-like pain in humans and is presumed to do the same in rodents. It is not known, however, if the mechanism for nitroglycerin headaches involves the same pathological processes as migraine. In the absence of known mechanisms, it becomes imperative that the model not only translates into successful clinical trials but also successfully reverse translates by demonstrating efficacy of current therapeutics. In this study female rats were given nitroglycerin and nociception was evaluated in OPADs. Estrous was not monitored. Based on the ED50 of nitroglycerin a dose of 10 mg/kg was used for experiments. Sumatriptan, caffeine, buprenorphine and morphine were administered to evaluate the reverse translatability of the model. We found that nitroglycerin did not produce mechanical allodynia in the face of the rats, which is reported to be a consequence of migraine in humans. Nitroglycerin reduced the animals’ participation in the assay. The reduced activity was verified using an assay to measure exploratory behavior. Furthermore, the effects of nitroglycerin were not reversed or prevented by agents that are effective acute therapies for migraine. Two interesting findings from this study, however, were that morphine and nitroglycerin interact to increase the rats’ tolerance of mechanical stimuli on their faces, and they work in concert to slow down the central motor pattern generator for licking on the reward bottle. These interactions suggest that nitroglycerin generated nitric oxide and mu opioid receptors interact with the same neuronal circuits in an additive manner. The interaction of nitroglycerin and morphine on sensory and motor circuits deserves additional examination. In conclusion, based on the results of this study the use of nitroglycerin at these doses in naïve female rats is not recommended as a model for migraine headaches.

From Mice to Monkeys? Beyond Orthodox Approaches to the Ethics of Animal Model Choice.

Simple SummaryNew tools, allowing scientists to make precise changes to mammal genomes, have made possible future increased use of larger mammals in biomedical research, such as primates, pigs, and dogs. This paper addresses ethical issues that are raised by using larger mammals instead of smaller ones in this research. Because scientists who use animals in research follow strict guidelines, we first examine what those guidelines suggest for using larger mammals. We then consider what philosophers, who write about the ethics of animal use, consider as the important questions in evaluating which (if any) animals are acceptable to use in research. We find that philosophical perspectives have typically been interested in the question of when or if animal use is justified, while biomedical research guidance has assumed that animal use is justified but defined specific limits to that use. To address directly the ethical questions that arise in the practice of biomedical research in selecting which animals to use, we consider an approach to ethics that is focused on character and living well (or flourishing). This paper is valuable to society in drawing attention to the ethical questions, rather than merely the scientific issues, that are important in selecting which animals to use in biomedical research.Recent developments in genome editing tools, along with limits in the translational potential of rodent models of human disease, have spurred renewed biomedical research interest in large mammals like nonhuman primates, pigs, and dogs. Such scientific developments raise ethical issues about the use of these animals in comparison with smaller mammals, such as mice and rats. To examine these ethical questions, we first consider standard (or “orthodox”) approaches, including ethics oversight within biomedical research communities, and critical theoretical reflections on animal research, including rights-based and utilitarian approaches. We argue that oversight of biomedical research offers guidance on the profession’s permitted uses of animals within a research setting and orthodox approaches to animal ethics questions when and whether animals should be used in biomedicine; however, neither approach sufficiently investigates the nuances of ethical practices within the research setting. To fill this lacuna, we consider a virtue ethical approach to the use of specific animal models in biomedicine. From this perspective, we argued that limitations on flourishing for large mammals in a research setting, as well as potential human-animal bonds, are two sources of likely ethical tensions in animal care and use in the context of larger mammals.

Kinetic modelling and quantification bias in small animal PET studies with [18F]AB5186, a novel 18 kDa translocator protein radiotracer.

IntroductionPositron Emission Tomography (PET) imaging with selective 18 kDa translocator protein (TSPO) radiotracers has contributed to our understanding on the role of inflammation in disease development and progression. With an increasing number of rodent models of human disease and expansion of the preclinical PET imaging base worldwide, accurate quantification of longitudinal rodent TSPO PET datasets is necessary. This is particularly relevant as TSPO PET quantification relies on invasive blood sampling due to lack of a suitable tissue reference region. Here we investigate the kinetics and quantification bias of a novel TSPO radiotracer [18F]AB5186 in rats using automatic, manual and image derived input functions.Methods[18F]AB5186 was administered intravenously and dynamic PET imaging was acquired over 2 hours. Arterial blood was collected manually to derive a population based input function or using an automatic blood sampler to derive a plasma input function. Manually sampled blood was also used to analyze the [18F]AB5186 radiometabolite profile in plasma and applied to all groups as a population based dataset. Kinetic models were used to estimate distribution volumes (VT) and [18F]AB5186 outcome measure bias was determined.Results[18F]AB5186 distribution in rats was consistent with TSPO expression and at 2 h post-injection 50% of parent compound was still present in plasma. Population based manual sampling methods and image derived input function (IDIF) underestimated VT by ~50% and 88% compared with automatic blood sampling, respectively. The VT variability was lower when using IDIF versus arterial blood sampling methods and analysis of the Bland-Altman plots showed a good agreement between methods of analysis.ConclusionQuantification of TSPO PET rodent data using image-derived methods, which are more amenable for longitudinal scanning of small animals, yields outcome measures with reduced variability and good agreement, albeit biased, compared with invasive blood sampling methods.

Implantable Microcoil for In-vivo Magnetic Resonance Spectroscopy

Nuclear Magnetic Resonance (NMR) allows a non-destructive study of molecular structures by the measurement of their atomic nuclei magnetization. Nonetheless, NMR technique still suffers from the sensitivity weakness compared to all other spectroscopy approaches. Therefore, the optimization of detection Radio Frequency (RF) coils and the reduction of the thermal noise will lead to an increase in signal resolution particularly around the regions of interest (ROI) within the living sample. In the case of sample with limited mass and volume, the sensitivity may be improved for when the size of the RF coil matches the sample size. In this study, we developed a microcoil (500x1000μm) dedicated to the NMR micro imaging (MRI) and micro localized spectroscopy (MRS) for biomedical applications on small rodent models of human diseases. Our NMR microcoil offer a sensitivity increased by 2.5, and limits of detection (LOD) of the main cerebral metabolites estimated by MRS in-vitro measurements in good concordance with analytical values given in literature. The realization of compact sensing system based on microcoil will open the door to numerous medical and industrial.

Wireless telemetry as an ideal tool for continuous intrahippocampal EEG recording in chronic epilepsy mouse models

Event Abstract Back to Event Wireless telemetry as an ideal tool for continuous intrahippocampal EEG recording in chronic epilepsy mouse models Yana Van Den Herrewegen1*, An Buckinx1*, Gino De Smet1, Ilse J. Smolders1 and Dimitri De Bundel1 1 Vrije Universiteit Brussel, Experimental Pharmacology (EFAR), cluster Neurosciences, Belgium Tethered recording systems are routinely used as a method for long-term continuous EEG monitoring in animal models of epilepsy. Nevertheless, tethered systems display some disadvantages when chronically used in mice, in some cases even compromising experiments and behavioral follow-up of the mice. Therefore, wireless telemetry systems are increasingly being used as an alternative method to precisely measure biopotentials in the rodent brain. As EEG recordings are the most powerful read-outs in animal models of epilepsy, we evaluated the use of wireless radio-telemetry in the intrahippocampal post-status epilepticus kainic acid model, an established mouse model for studying temporal lobe epilepsy and epileptogenesis. Via intraperitoneal implantation of a radiofrequency transmitter (ETA-F10, DSI) and electrodes positioned in the hippocampus, we were able to record intrahippocampal signals for up to two months. We could clearly monitor the epileptic activity during the status epilepticus, followed by a short latent period and the subsequent occurrence of the typical spontaneous epileptic discharges. This study discusses the advantages of telemetric EEG recordings and strategies to maximize the signal-to-noise ratio in order to obtain high-quality deep-brain EEG recordings. In conclusion, wireless telemetry systems are a valuable EEG monitoring method in the intrahippocampal kainic acid mouse model and other models of chronic epilepsy in mice. References Bouilleret V, Ridoux V, Depaulis A, et al. Recurrent seizures and hippocampal sclerosis following intrahippocampal kainate injection in adult mice: electroencephalography, histopathology and synaptic reorganization similar to mesial temporal lobe epilepsy. Neuroscience. 1999; Mar;89(3):717-29. Duveau V, Pouyatos B, Bressand K, et al. Differential Effects of Antiepileptic Drugs on Focal Seizures in the Intrahippocampal Kainate Mouse Model of Mesial Temporal Lobe Epilepsy. CNS Neuroscience & Therapeutics: CNS Neurosci Ther. 2016;(22):497-50. doi: 10.1111/cns.12523 Lundt A, Wormuth C, Siwek ME, et al. EEG Radiotelemetry in Small Laboratory Rodents: A Powerful State-of-the Art Approach in Neuropsychiatric, Neurodegenerative, and Epilepsy Research. Neural Plasticity. 2016;2016:8213878. doi:10.1155/2016/8213878. Twele F, Tollner K, Bankstahl M, Loscher W, et al. The effects of carbamazepine in the intrahippocampal kainate model of temporal lobe epilepsy depend on seizure definition and mouse strain. Epilepsia Open, 2016; 1(1):45–60,. doi: 10.1002/epi4.2 Zayachkivsky A, Lehmkuhle MJ, Dudek FE. Long-term Continuous EEG Monitoring in Small Rodent Models of Human Disease Using the Epoch Wireless Transmitter System. Journal of Visualized Experiments : JoVE. 2015;(101):52554. doi:10.3791/52554. Keywords: wireless radio-telemetry, EEG, Epilepsy, Temporal Lobe, mouse models, Seizures Conference: 12th National Congress of the Belgian Society for Neuroscience, Gent, Belgium, 22 May - 22 May, 2017. Presentation Type: Poster Presentation Topic: Novel Methods and Technology Development Citation: Van Den Herrewegen Y, Buckinx A, De Smet G, Smolders IJ and De Bundel D (2019). Wireless telemetry as an ideal tool for continuous intrahippocampal EEG recording in chronic epilepsy mouse models. Front. Neurosci. Conference Abstract: 12th National Congress of the Belgian Society for Neuroscience. doi: 10.3389/conf.fnins.2017.94.00001 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 02 May 2017; Published Online: 25 Jan 2019. * Correspondence: Miss. Yana Van Den Herrewegen, Vrije Universiteit Brussel, Experimental Pharmacology (EFAR), cluster Neurosciences, Brussels, 1090, Belgium, yana.van.den.herrewegen@vub.ac.be Miss. An Buckinx, Vrije Universiteit Brussel, Experimental Pharmacology (EFAR), cluster Neurosciences, Brussels, 1090, Belgium, an.buckinx@vub.be Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Yana Van Den Herrewegen An Buckinx Gino De Smet Ilse J Smolders Dimitri De Bundel Google Yana Van Den Herrewegen An Buckinx Gino De Smet Ilse J Smolders Dimitri De Bundel Google Scholar Yana Van Den Herrewegen An Buckinx Gino De Smet Ilse J Smolders Dimitri De Bundel PubMed Yana Van Den Herrewegen An Buckinx Gino De Smet Ilse J Smolders Dimitri De Bundel Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

T Cell Subsets and Associated Cytokines in Chronic Graft-Versus-Host-Disease Using G-CSF Primed Bone Marrow in Allogeneic Hematopoietic Stem Cell Transplantation

BackgroundGraft versus host disease (GVHD) is the major complication of allogeneic hematopoietic stem cell transplantation. It is characterized by an imbalance between the effector and regulatory arms of the immune system which results in the over production of inflammatory cytokines. Regulatory T (T regs) cells and T helper 17 (Th17) cells are two recently described lymphocyte subsets with opposing actions. Both can develop from naïve CD4+ T cell precursors under the influence of TGFβ1. Th17 lymphocytes, are key effector cells in rodent models of human diseases including GVHD. The other subset, T regs, is essential for dominant immunologic tolerance. At our institution, patients transplanted using G-CSF primed bone marrow (G-BM), have a lower incidence of acute and chronic GVHD when compared to those transplanted with peripheral blood and not primed bone marrow. Some microenvironment characteristics of this hematopoietic stem cells (HSC) source remain unknown, as well as the difference between Tregs, Th17 and cytokine levels in patients who develop GVHD and those who do not.ObjectiveTo analyze the characteristics of thirty-eight G-BM donor samples, identifying lymphocytes subsets and associated cytokines, and comparing patients who developed chronic GVHD (cGVHD) and those who did not.Materials and MethodsA prospective analysis was performed in 38 G-BM samples from donors from 1999 to 2016. Mononuclear cells were defrosted, counted, and viability was evaluated. A 24 hour resting with RPMI, and posterior activation with PMA (50 ng/ml) for 48 hours was performed. Cells were harvested and cytokines were evaluated by flow cytometry (CBA assay).From each sample, one million mononuclear cells were permeabilized, fixed, and stained with CD4-FITC, IL17A-PE, IFN-γ APC, and IL-4 PECy7, for their posterior phenotipication by flow cytometry. The samples were obtained in a BD LSR Fortessa cytometry, and analyzed with the Flow-Jo software. Patients (recipients) information was analyzed using SPSS v.21.ResultsGVHD incidence was reported as following: Three (8%) patients developed acute GVHD (2 grade II, and 1 grade IV), 11 patients (29%) developed chronic GVHD (9% extensive, and 91% limited), and 24 patients did not present either.Mononuclear cells from G-BM from donors of patients who developed cGVHD showed a pro inflammatory response, characterized by an increased concentration of IL-17A (15.5 vs 0.71 pg/mL, p=0.013), TNF-α (80.27 vs 0.13 pg/mL, p=0.001), and IL-6 (4953.6 vs 11.75 pg/mL, p=0.025), after a mitogenic stimulation, compared to cells from donors of patients who did not developed GVHD. On the other hand, a decreased IL-10 production (2.62 vs 52.81 pg/mL, p=0.001) was documented in mononuclear cells from donors of patients who developed chronic GVHD, compared to donor cells of patients who did not. No significant difference in the production of IL-2, IL-4, and IFN-γ was observed. There was no difference in Th1 and Th2 between both groups, but mononuclear cells from donors of patients who developed chronic GVHD had a higher percentage of Th17 (1.02% vs 0.46%, p<0.001), and less Tregs (0.88% vs 1.95%, p<0.001), compared to those who did not developed GVHD.ConclusionsPatients who develop cGVHD (29%) are characterized by a pro inflammatory response with an increased production of IL-17A, IL-6, and IFN-γ, and also a major percentage of Th17 cells. Also, a decreased suppressive response was documented with reduced IL-10 and Tregs levels. The low incidence of cGVHD show that G-CSF primed bone marrow is an excellent source for allogeneic HSC transplantations, and would be useful to compare these results with other HSC sources. DisclosuresNo relevant conflicts of interest to declare.

Species Cross-Reactivity of Antibodies Used to Treat Ophthalmic Conditions.

The species cross-reactivity of the monoclonal antibodies infliximab, bevacizumab, and an anti-VEGF-B antibody, 2H10, in humans and rodents was determined. The binding of infliximab to human, mouse, and rat TNF-α, of bevacizumab to human, mouse, and rat VEGF-A, and of the 2H10 antibody to human, mouse, and rat VEGF-B was evaluated by ELISA. The sequence of human, mouse, and rat TNF-α and VEGF-A at the binding sites for infliximab and bevacizumab were compared. Infliximab bound to human TNF-α, but no binding to mouse or rat TNF-α was detected between 10 pg/mL and 10 μg/ml. Sequence comparison of the binding site revealed four changes in mouse and five in rat TNF-α compared with human. Bevacizumab bound strongly to human VEGF-A, but showed 5-log weaker binding to both mouse and rat VEGF-A. There was a single amino acid substitution in mouse and rat VEGF-A at the bevacizumab binding site. The 2H10 antibody displayed a similar binding profile to human, mouse, and rat VEGF-B. The species cross-reactivity of monoclonal antibodies should be determined prior to their use in preclinical animal models. The 2H10 antibody binds to human, mouse, and rat VEGF-B making it suitable for testing in rodent models of human disease.

Long-term Continuous EEG Monitoring in Small Rodent Models of Human Disease Using the Epoch Wireless Transmitter System

Many progressive neurologic diseases in humans, such as epilepsy, require pre-clinical animal models that slowly develop the disease in order to test interventions at various stages of the disease process. These animal models are particularly difficult to implement in immature rodents, a classic model organism for laboratory study of these disorders. Recording continuous EEG in young animal models of seizures and other neurological disorders presents a technical challenge due to the small physical size of young rodents and their dependence on the dam prior to weaning. Therefore, there is not only a clear need for improving pre-clinical research that will better identify those therapies suitable for translation to the clinic but also a need for new devices capable of recording continuous EEG in immature rodents. Here, we describe the technology behind and demonstrate the use of a novel miniature telemetry system, specifically engineered for use in immature rats or mice, which is also effective for use in adult animals.

Long-term Continuous EEG Monitoring in Small Rodent Models of Human Disease Using the Epoch Wireless Transmitter System.

Many progressive neurologic diseases in humans, such as epilepsy, require pre-clinical animal models that slowly develop the disease in order to test interventions at various stages of the disease process. These animal models are particularly difficult to implement in immature rodents, a classic model organism for laboratory study of these disorders. Recording continuous EEG in young animal models of seizures and other neurological disorders presents a technical challenge due to the small physical size of young rodents and their dependence on the dam prior to weaning. Therefore, there is not only a clear need for improving pre-clinical research that will better identify those therapies suitable for translation to the clinic but also a need for new devices capable of recording continuous EEG in immature rodents. Here, we describe the technology behind and demonstrate the use of a novel miniature telemetry system, specifically engineered for use in immature rats or mice, which is also effective for use in adult animals.

Impact of the gut microbiota on rodent models of human disease.

Traditionally bacteria have been considered as either pathogens, commensals or symbionts. The mammal gut harbors 10(14) organisms dispersed on approximately 1000 different species. Today, diagnostics, in contrast to previous cultivation techniques, allow the identification of close to 100% of bacterial species. This has revealed that a range of animal models within different research areas, such as diabetes, obesity, cancer, allergy, behavior and colitis, are affected by their gut microbiota. Correlation studies may for some diseases show correlation between gut microbiota composition and disease parameters higher than 70%. Some disease phenotypes may be transferred when recolonizing germ free mice. The mechanistic aspects are not clear, but some examples on how gut bacteria stimulate receptors, metabolism, and immune responses are discussed. A more deeper understanding of the impact of microbiota has its origin in the overall composition of the microbiota and in some newly recognized species, such as Akkermansia muciniphila, Segmented filamentous bacteria and Faecalibacterium prausnitzii, which seem to have an impact on more or less severe disease in specific models. Thus, the impact of the microbiota on animal models is of a magnitude that cannot be ignored in future research. Therefore, either models with specific microbiota must be developed, or the microbiota must be characterized in individual studies and incorporated into data evaluation.

Proliferative activity of liver growth factor is associated with an improvement of cigarette smoke-induced emphysema in mice.

Cigarette smoke (CS)-induced emphysema is a major component of chronic obstructive pulmonary disease (COPD). COPD treatment is based on the administration of bronchodilators and corticosteroids to control symptoms and exacerbations, however, to date, there are no effective therapies to reverse disease progression. Liver growth factor (LGF) is an albumin-bilirubin complex with mitogenic properties, whose therapeutic effects have previously been reported in a model of emphysema and several rodent models of human disease. To approach the therapeutic effect of LGF in a model of previously established emphysema, morphometric and lung function parameters, matrix metalloproteinase (MMP) activity and the expression of several markers, such as VEGF, PCNA, 3NT and Nrf2, were assessed in air-exposed and CS-exposed C57BL/6J male mice with and without intraperitoneal (i.p.) injection of LGF. CS-exposed mice presented a significant enlargement of alveolar spaces, higher alveolar internal area and loss of lung function that correlated with higher MMP activity, higher expression of 3NT and lower expression of VEGF. CS-exposed mice injected with LGF, showed an amelioration of emphysema and improved lung function, which correlated with lower MMP activity and 3NT expression and higher levels of VEGF, PCNA and Nrf2. Taken together, this study suggests that LGF administration ameliorates CS-induced emphysema, highlights the ability of LGF to promote alveolar cell proliferation and may be a promising strategy to revert COPD progression.

Meeting Report

Urinary system toxicity is a significant concern to pathologists in the hazard identification, drug and chemical safety evaluation, and diagnostic service industries worldwide. There are myriad known human and animal urinary system toxicants, and investigatory renal toxicology and pathology is continually evolving. The system-specific Research Triangle Park (RTP) Rodent Pathology Course biennially serves to update scientists on the latest research, laboratory techniques, and debates. The Sixth RTP Rodent Pathology Course, Urinary Pathology, featured experts from the government, pharmaceutical, academic, and diagnostic arenas sharing the state of the science in urinary pathology. Speakers presented on a wide range of topics including background lesions, treatment-related non-neoplastic and neoplastic lesions, transgenic rodent models of human disease, diagnostic imaging, biomarkers, and molecular analyses. These seminars were accompanied by case presentation sessions focused on usual and unusual lesions, grading schemes, and tumors.

The MAM Rodent Model of Schizophrenia

Rodent models of human disease are essential to obtain a better understanding of disease pathology, the mechanism of action underlying conventional treatments, as well as for the generation of novel therapeutic approaches. There are a number of rodent models of schizophrenia based on either genetic manipulations, acute or sub-chronic drug administration, or developmental disturbances. The prenatal methylazoxymethanol acetate (MAM) rodent model is a developmental disruption model gaining increased attention because it displays a number of histological, neurophysiological, and behavioral deficits analogous to those observed in schizophrenia patients. This unit describes the procedures required to safely induce the MAM phenotype in rats. In addition, we describe a simple behavioral procedure, amphetamine-induced hyperlocomotion, which can be utilized to verify the MAM phenotype.

Cytoarchitecture of mouse and rat cingulate cortex with human homologies

A gulf exists between cingulate area designations in human neurocytology and those used in rodent brain atlases with a major underpinning of the former being midcingulate cortex (MCC). The present study used images extracted from the Franklin and Paxinos mouse atlas and Paxinos and Watson rat atlas to demonstrate areas comprising MCC and modifications of anterior cingulate (ACC) and retrosplenial cortices. The laminar architecture not available in the atlases is also provided for each cingulate area. Both mouse and rat have a MCC with neurons in all layers that are larger than in ACC and layer Va has particularly prominent neurons and reduced neuron densities. An undifferentiated ACC area 33 lies along the rostral callosal sulcus in rat but not in mouse and area 32 has dorsal and ventral subdivisions with the former having particularly large pyramidal neurons in layer Vb. Both mouse and rat have anterior and posterior divisions of retrosplenial areas 29c and 30, although their cytology is different in rat and mouse. Maps of the rodent cingulate cortices provide for direct comparisons with each region in the human including MCC and it is significant that rodents do not have a posterior cingulate region composed of areas 23 and 31 like the human. It is concluded that rodents and primates, including humans, possess a MCC and this homology along with those in ACC and retrosplenial cortices permit scientists inspired by human considerations to test hypotheses on rodent models of human diseases.

Synthesis of triheptanoin and formulation as a solid diet for rodents

AbstractTriheptanoin‐enriched diets have been successfully used in the experimental treatment of various metabolic disorders. Maximal therapeutic effect is achieved in the context of a ketogenic diet where triheptanoin oil provides 30–40% of the daily caloric intake. However, pre‐clinical studies using triheptanoin‐rich diets are hindered by the difficulty of administering to laboratory animals as a solid foodstuff. In the present study, we successfully synthesized triheptanoin to the highest standards of purity from glycerol and heptanoic acid, using sulfonated charcoal as a catalyst. Triheptanoin oil was then formulated as a solid, stable and palatable preparation using a ketogenic base and a combination of four commercially available formulation agents: hydrophilic fumed silica, hydrophobic fumed silica, microcrystalline cellulose, and talc. Diet compliance and safety was tested on C57Bl/6 mice over a 15‐week period, comparing overall status and body weight change.Practical applications: This work provides a complete description of (i) an efficient and cost‐effective synthesis of triheptanoin and (ii) its formulation as a solid, stable, and palatable ketogenic diet (triheptanoin‐rich; 39% of the caloric intake) for rodents. Triheptanoin‐rich diets will be helpful on pre‐clinical experiments testing the therapeutic efficacy of triheptanoin in different rodent models of human diseases. In addition, using the same solidification procedure, other oils could be incorporated into rodent ketogenic diet to study their dosage and long‐term effects on mammal health and development. This approach could be extremely valuable as ketogenic diet is widely used clinically for epilepsy treatment.

Gold nanoparticle labeling of cells is a sensitive method to investigate cell distribution and migration in animal models of human disease

The ability to track cells in small-animal models of human disease is important because it gives the potential to improve our understanding of the processes of disease progression as well as our understanding of the therapeutic effects of interventions. In this study gold nanoparticles have been used as a permanent marker of implanted normal and malignant cell grafts in combination with a suitable x-ray apparatus. Using x-ray computed tomography the micrometric three-dimensional distribution of these marked cells could be displayed with penetration depth, high cell sensitivity and high spatial resolution in rodent models of human diseases. In principle the method allows quantification of cell numbers at any anatomical location over time in small animals. From the Clinical Editor In this paper, a gold nanoparticle based cell labeling method is presented for in vivo cell tracking via micro-CT. Although a tumor model is shown in this pilot experiment, the method can theoretically be utilized in cell labeling experiments of any kind.

A Method for Serial Selective Arterial Catheterization and Digital Subtraction Angiography in Rodents

Imaging is a key element in the study of many rodent models of human diseases. The application of DSA has been limited in these studies in part because of a lack of a method that allows serial intra-arterial examinations to be performed during an extended period of time. It was our intent to develop and test a method for performing sequential arterial catheterizations and DSA in rats. Using a transfemoral approach, we subjected 12 adult male Harvey rats to 3 sequential DSA examinations during a 6- to 8-week period. At each examination, 2 selective arterial catheterizations and a DSA were performed. Animals were monitored for ill effects, and images from the 3 examinations were compared for quality and the presence of any arterial injury. Ten of the 12 rats survived all 3 examinations. There were no adverse effects noted and no evidence of arterial injury from the examinations. With the technique described, it is possible to perform serial arterial catheterizations and DSA in rats. This technique will be useful as an adjunct in the use of rodents for the study of human diseases.

Discovery and validation of colonic tumor-associated proteins via metabolic labeling and stable isotopic dilution.

The unique biology of a neoplasm is reflected by its distinct molecular profile compared with normal tissue. To understand tumor development better, we have undertaken a quantitative proteomic search for abnormally expressed proteins in colonic tumors from Apc(Min/+) (Min) mice. By raising pairs of Min and wild-type mice on diets derived from natural-abundance or (15)N-labeled algae, we used metabolic labeling to compare protein levels in colonic tumor versus normal tissue. Because metabolic labeling allows internal control throughout sample preparation and analysis, technical error is minimized as compared with in vitro labeling. Several proteins displayed altered expression, and a subset was validated via stable isotopic dilution using synthetic peptide standards. We also compared gene and protein expression among tumor and nontumor tissue, revealing limited correlation. This divergence was especially pronounced for species showing biological change, highlighting the complementary perspectives provided by transcriptomics and proteomics. Our work demonstrates the power of metabolic labeling combined with stable isotopic dilution as an integrated strategy for the identification and validation of differentially expressed proteins using rodent models of human disease.