Animal Behavior Experiments Research Articles

Effect of inulin on preventing drunkenness and relieving acute alcoholic intoxication of mice and preparation of its hangover beverage

AbstractThe aim of this study was to evaluate the effects of different types of inulin on acute alcoholic intoxication (AAI) in mice and prepare its hangover beverage. Basic physical and chemical properties of different types of inulin (short‐chain inulin, long‐chain inulin, and phosphorylated long‐chain inulin) were analyzed and given by gavage at a dose of 400 mg kg−1 day−1 for a continuous period of 7 days through animal behavior experiments, and the inebriation percentage, mortality rate, duration of inebriation, and sobering time were recorded with the righting reflex as the judgment criterion. The results showed that, compared with the control group, the drunkenness and mortality rates of short‐chain inulin decreased by 12% and 100%, respectively, and the sober time decreased by 18%, while alcohol tolerance was also improved. The best formula for a short‐chain inulin hangover drink was determined to be: 0.4% granulated sugar, 0.5% citric acid, and 0.5% pectin. These suggest that short‐chain inulin may have potential in preventing AAI.

Human Circulatory/Respiratory-Inspired Comprehensive Air Purification System.

The circulatory and respiratory systems in humans are marvels of biological engineering that exhibit competence in maintaining homeostasis. These systems not only shield the organism from external contaminants but also orchestrate the vital gases via the bloodstream to sustain cellular respiration and metabolic processes across diverse tissues. It is noticed that spaces inhabited encounter challenges akin to those of the human body: protecting the indoor air from external pollutants while removing anthropogenic byproducts like carbon dioxide (CO2), particulate matters (PM), and volatile organic compounds (VOCs) tooutside. A biomimetic approach, composed of a microbubble-based gas exchanger and circulating liquid inspired by alveoli, capillary beds, and bloodstream of the human circulatory/respiratory system, offer an innovative solution for comprehensive air purification of hermetic spaces. Circulatory/respiratory-inspired air purification system (CAPS) ensure both continuous removal of PM and exchange of gas species between indoor and outdoor environments to maintain homeostasis. The effectiveness of this system is also supported by animal behavior experiments with and without CAPS, showing an effect of reducing CO2 concentration by 30% and increasing mice locomotor activity by 53%. CAPS is expected to evolve into robust and comprehensive air purification schemes through the networked integration of plural internal and external environments.

Gastrodin ameliorates depressive-like behaviors via modulating gut microbiota in CUMS-induced mice

PurposeDepression is a psychiatric disorder and the treatment of depression is an urgent problem that need to be solved. Gastrodin (GAS) is a Traditional Chinese Medicine from an orchid and is used for neurological diseases, including depressive disorders. MethodsTo assess the effect of GAS on gut microbiota of depressive mice, we established a chronic unpredictable mild stress (CUMS)-induced mouse model, and GAS was administered to one group of the mice. Animal behavior experiments were used to detect depressive-like behaviors, and 16 S rRNA gene analysis was applied to detect the gut microbiota of each group. All raw sequences were deposited in the NCBI Sequence Read Archive under accession number SRP491061. ResultsGAS treatment significantly improved depressive-like behaviors as well as the diversity and abundance of the gut microbiota. The depressive-like behaviors of the CUMS-GAS group were improved in different degrees compared with the CUMS group. The linear discriminant analysis (LDA) of the gut microbiota showed that the makeup of the gut microbiota in mice changed dramatically in the CUMS-GAS group, compared with the CUMS group, Bacteroides (LDA = 3.94, P < 0.05) were enriched in the CUMS-GAS group at the genus level. In comparison to the CUMS group, the CUMS-GAS group had a greater concentration numbers of Lactobacillus, Corynebacterium, Staphylococcus, Bacteroides, Psychrobacter, and Alistipes. ConclusionOur results suggested that GAS improved depressive-like behaviors in mice and impacted the microbial composition of the gut. Our research indicated that dysbiosis of the gut microbiota may be affected by GAS treatment, which improved depressive-like behaviors in the CUMS-induced mouse model of depression.

Ethorobotic rats for rodent behavioral research: design considerations.

The development of robots as tools for biological research, sometimes termed "biorobotics", has grown rapidly in recent years, fueled by the proliferation of miniaturized computation and advanced manufacturing techniques. Much of this work is focused on the use of robots as biomechanical models for natural systems. But, increasingly, biomimetic robots are being employed to interact directly with animals, as component parts of ethology studies in the field and behavioral neuroscience studies in the laboratory. While it has been possible to mechanize and automate animal behavior experiments for decades, only recently has there been the prospect of creating at-scale robotic animals containing the sensing, autonomy and actuation necessary for complex, life-like interaction. This not only opens up new avenues of enquiry, but also provides important ways to improve animal welfare, both by reducing or replacing the use of animal subjects, and by minimizing animal distress (if robots are used judiciously). This article will discuss the current state of the art in robotic lab rats, providing perspective on where research could be directed to enable the safe and effective use of biorobotic animals.

Molecular networking-assisted systematical profiling and the in vivo neuroprotective effect of ellagitannins from the Melastoma dodecandrum Lour

BackgroundEllagitannins (ETs) are a major classification of natural tannins, with relatively large and complex structures. ETs from medicinal plants are focused increasingly due to urolithins, a kind of intestinal metabolite of ETs, which showed promising anti-Alzheimer's disease (AD) effects. Melastoma dodecandrum (MD), a widely used traditional Chinese medicine is rich in ETs, but their chemistry and potential neuroprotective effects have not been investigated. PurposeThis study aimed to identify the chemical composition of ETs in the crude extract of MD and to investigate their neuroprotective effects in vivo. MethodsUPLC-QTOF-MS-based molecular networking (MN) and structural characterization were applied to targeted profiling of the MD-ETs. Animal behavior experiments, including the novel object recognition test (NOR), open field test (OFT), and Morris water maze test (MWM), were conducted to assess the memory improvement effects of MD-ETs in AD model mice. ResultsA total of 70 ETs, ranging from monomers to tetramers, were tracked and characterized in the MD extract using MN-guided targeted profiling, with 59 of them reported for the first time in this species. MD-ETs significantly improved memory impairment in AD mice, as indicated by decreased escape latency, increased number of crossings and target quadrant distance in MWM, increased rearing number in OFT, and increased preference index in NOR. ConclusionThis study systematically characterized the composition and structural features of ETs in MD using targeted LC-MS profiling, expanding the chemical information of ETs in MD. Furthermore, the results demonstrate that MD-ETs have significant effects on improving impaired memory in AD mice, suggesting their potential as alternative natural medicines for the treatment of neurodegenerative diseases.

Transcriptomic and metabolomic studies on the protective effect of molecular hydrogen against nuclear electromagnetic pulse-induced brain damage.

Excessive doses of electromagnetic radiation pose a negative impact on the central nervous system and lead to mental disorders. Molecular hydrogen can scavenge intracellular hydroxyl radicals, acting as an antioxidant, anti-apoptotic and anti-inflammatory agent. We seek to assess the capability of molecular hydrogen to ameliorate brain damage induced by electromagnetic radiation. NEMP (nuclear electromagnetic pulse), a subset of electromagnetic pulse with high voltage value that could cause severe brain injury, was applied to this study. Male wild-type rats were divided into four groups: the control group, the H2 (Molecular hydrogen) group, the NEMP group and the NEMP+H2 group. Rats in the H2 group and the NEMP+H2 group were fed with saturated hydrogen-rich water from 3 days before NEMP exposure (electromagnetic field intensity 400 kV/m, rising edge 20 ns and pulse width 200 ns) to the day of sacrifice. One day after exposure, animal behavior experiments were performed, and samples for transcriptomics and metabolomics analysis were collected. Seven days after exposure, histopathological experiments were conducted. The data from the elevated plus maze and the open field test showed that NEMP exposure elicited anxiety-like behavior in rats, which could be alleviated by H2 treatment. Histopathological results manifested that NEMP exposure-induced injuries of the neurons in the hippocampus and amygdala could be attenuated by H2 treatment. Transcriptomic results revealed that NEMP exposure had a profound effect on microtubule structure in the brain. And the combined analysis of transcriptomics and metabolomics showed that H2 has a significant impact on the neuroactive ligand-receptor interaction, synaptic vesicle cycle and synapse etc. Moreover, it was indicated that the glutathione metabolic pathway played a vital role in the NEMP exposure-induced damage and the protective activity of H2. H2 is identified as a potent agent against NEMP exposure-induced brain damage and has the potential to be a promising electromagnetic radiation protectant.

Ameliorative Effect of Medicarpin on Scopolamine-Induced Cognitive Impairment in Mice

The ameliorative effect of medicarpin (MC) was investigated by animal behavioral experiments such as Morris water maze (MWM), Y-maze, and passive avoidance test (PAT), using scopolamine-induced cognitively impaired mice. The scopolamine (5 mg/kg), donepezil (5 mg/kg), and MC (5 and 15 mg/kg) were administered by intraperitoneal injection at a volume of 0.3 mL. In the MWM, the escape latency times of MC-treated groups were significantly decreased compared with the scopolamine-treated negative control, and times spent in the platform zone of MC-treated groups were increased dose-dependently. In the Y-maze, the zone alternations of the MC-treated group were increased to the level of the donepezil-treated positive control. In the PAT, the crossing times of MC-treated groups were significantly higher than those of the negative control with dose-dependency. On the other hand, the monoamine oxidase (MAO)-A, MAO-B, and acetylcholinesterase (AChE) activities, relating to cognitive functions, in hippocampus treated with MC were decreased. In addition, the AChE activity in SH-SY5Y cells was significantly decreased. In Western blots, phosphorylated cyclic adenosine monophosphate (cAMP) response element-binding protein (p-CREB), brain-derived neurotrophic factor (BDNF), phosphorylated protein kinase B (p-Akt), and dopamine D2 receptor (D2R) levels in the hippocampus were higher than those of the negative control. In addition, p-CREB, BDNF, p-Akt, and D2R levels in SH-SY5Y cells treated with MC were significantly increased. These results showed that MC ameliorated a cognitive function along with increased BDNF and D2R expressions, and they suggested that MC could be used for the treatment of neurological disorders such as Alzheimer’s disease and Parkinson’s disease.

Intermittent hypoxic conditioning restores neurological dysfunction of mice induced by long-term hypoxia.

Central nervous system diseases are associated with hypoxia, which usually cause irreversible nerve damage, but the underlying mechanism is unclear and effective intervention strategies are lacking. This study was designed to explore the mechanism and treatment strategy of hypoxia-induced nerve injury. In this study, 13% O2 was used to treat mice for 0, 1, 3 7, and 14 days, Morris water maze and other animal behavior experiments were used to evaluate the neurological function of mice. TUNEL, BrdU, PCNA, DCX, and SOX2 staining were used to observe the apoptosis and proliferation of mouse neurons. RT-PCR and Iba1 staining were used to evaluate the release of inflammatory factors IL-1β, IL-6, and TNF-α and the activation of microglia. Short-term hypoxia promotes neurogenesis, while long-term hypoxia inhibits neurogenesis. The changes in hypoxia-induced neurogenesis were positively correlated with neurological functions, but negatively correlated with apoptosis. Moreover, intermittent hypoxic conditioning restored long-term hypoxia-induced neurological dysfunction by promoting neural stem cell generation and inhibiting the release of inflammatory factors IL-1β, IL-6, and TNF-α and the activation of microglia. Hypoxia promoted neurogenesis in a time-dependent manner, and intermittent hypoxic conditioning exerted a neuroprotective effect through promoting neural stem cell generation and suppressing inflammation induced by long-term hypoxia stress, which provided a novel concept to develop a treatment for hypoxia-related brain injury.

Tyrosine 7.43 is important for mu-opioid receptor downstream signaling pathways activated by fentanyl.

G protein–coupled receptors can signal through both G proteins and ß-arrestin2. For the µ-opioid receptor (MOR), early experimental evidence from a single study suggested that G protein signaling mediates analgesia and sedation, whereas ß-arrestin signaling mediates respiratory depression and constipation. Then, receptor mutations were used to clarify which residues interact with ligands to selectively regulate signals in a ligand-specific manner. However, there is no systematic study on how to determine these residues and clarify the molecular mechanism of their influence on signal pathways. We have therefore used molecular docking to predict the amino acid sites that affect the binding of ligands and MOR. Then, the corresponding sites were mutated to determine the effect of the structural determinant of MOR on Gi/o protein and ß-arrestin pathways. The pharmacological and animal behavioral experiments in combination with molecular dynamics simulations were used to elucidate the molecular mechanism of key residues governing the signaling. Without affecting ligand binding to MOR, MORY7.43A attenuated the activation of both Gi/o protein and ß-arrestin signaling pathways stimulated by fentanyl, whereas it did not change these two pathways stimulated by morphine. Likewise, the activation peak time of extracellular regulated protein kinases was significantly prolonged at MORY7.43A compared with that at MORwildtype stimulated by fentanyl, but there was no difference stimulated by morphine. In addition, MORY7.43A significantly enhanced analgesia by fentanyl but not by morphine in the mice behavioral experiment. Furthermore, the molecular dynamics simulations showed that H6 moves toward the cellular membrane. H6 of the fentanyl–Y7.43A system moved outward more than that in the morphine–Y7.43A system. Y7.43 mutation disrupted hydrophobic interactions between W6.48 and Y7.43 in the fentanyl–Y7.43A system but not in the morphine–Y7.43A system. Our results have disclosed novel mechanisms of Y7.43 mutation affecting MOR signaling pathways. Y7.43 mutation reduced the activation of the Gi/o protein pathway and blocked the ß-arrestin2 recruitment, increased the H6 outward movement of MOR, and disrupted hydrophobic interactions. This may be responsible for the enhanced fentanyl analgesia. These findings are conducive to designing new drugs from the perspective of ligand and receptor binding, and Y7.43 is also expected to be a key site to structure optimization of synthesized compounds.

Intervention effects of miR-125b-5p on cognitive dysfunction induced by traumatic brain injury in rats and its mechanisms

To investigate the effects and molecular mechanisms of miR-125b-5p on cognitive dysfunction caused by traumatic brain injury (TBI). The rats were randomly divided into control group, TBI group (model group), NC Agomir group (false negative group) and miR-125b-5p agomir group (high expression group), with 5 rats in each group. The false negative group and the high expression group were injected with NC agomir and miR-125b-5p agomir, respectively. The brain injury model was established by modified Feeney method except control group. Animal behavioral experiments were utilized for evaluation of the motor coordination, learning and memory and the degree of nerve damage in rats; and enzyme-linked immunosorbent assays (ELISA) and Western blot (WB) were used for determination of the expression levels of inflammatory factors and nerve-related factors in the hippocampus of rats in each group respectively. Finally, combined with bioinformatics, downstream target genes of miR-125b-5p were predicted and verified by reverse transcription polymerase chain reaction (RT-PCR) and WB. Compared with control group, mir-125b-5p expression level, motor coordination ability, learning and memory ability, brain-derived neurotrophic factor(BDNF) and nerve growth factor(NGF) expression levels of rats in model group and false negative group were decreased significantly, the MNSS score, the expressions of interleukins (IL-1β, IL 6), tumor necrosis factor-α(TNF-α) and glial fibrillary acid protein(GFAF) were increased significantly (P＜0.01);However, compared with model group and false negative group, the above situation of rats in high expression group was opposite (P＜0.01). Bioassay showed that MMP-15 was the downstream target gene of miR-125b-5p. Compared with the control group, the expression of MMP-15 in model group and false negative group was increased significantly (P＜0.01);Compared with model group and false negative group, the expression of MMP-15 in high expression group was decreased significantly (P＜0.01) . miR-125b-5p can improve cognitive dysfunction induced by TBI in rats, which may be related to regulating the expression level of MMP-15, thereby inhibiting the neuroinflammatory response after TBI and promoting neuronal regeneration.

Four Chemotherapeutic Compounds That Limit Blood-Brain-Barrier Invasion by Toxoplasma gondii

Background: Toxoplasma gondii, an intracellular protozoan parasite, exists in the host brain as cysts, which can result in Toxoplasmic Encephalitis (TE) and neurological diseases. However, few studies have been conducted on TE, particularly on how to prevent it. Previous proteomics studies have showed that the expression of C3 in rat brains was up-regulated after T. gondii infection. Methods: In this study, we used T. gondii to infect mice and bEnd 3 cells to confirm the relation between T. gondii and the expression of C3. BEnd3 cells membrane proteins which directly interacted with C3a were screened by pull down. Finally, animal behavior experiments were conducted to compare the differences in the inhibitory ability of TE by four chemotherapeutic compounds (SB290157, CVF, NSC23766, and Anxa1). Results: All chemotherapeutic compounds in this study can inhibit TE and cognitive behavior in the host. However, Anxa 1 is the most suitable material to inhibit mice TE. Conclusion: T. gondii infection promotes TE by promoting host C3 production. Anxa1 was selected as the most appropriate material to prevent TE among four chemotherapeutic compounds closely related to C3.

Preparation and evaluation of liposome with ropivacaine ion-pairing in local pain management

Local analgesia is one of the most desirable methods for postoperative pain control, while the existing local anesthetics have a short duration of analgesic effect. Nano-drug carriers have been widely used in various fields and provide an excellent strategy for traditional drugs. Although the existing liposomes for local anesthetics have certain advantages, their instability and complexity of the preparation process still cannot be ignored. Here, we developed novel ropivacaine hydrochloride liposomes with improved stability and sustained release performance by combining ropivacaine hydrochloride with sodium oleate in liposomes via hydrophobic ion-pairing (HIP). The liposomes are easy to prepare, inexpensive, and suitable for mass production. The infrared (IR), particle size, and Zeta potential measurements adequately characterized the complex, which showed a diameter of 81.09 nm and a zeta potential of −83.3 mV. Animal behavioral experiments, including the hot plate test and von Frey fiber test, demonstrated that the liposome system had a prolonged analgesic effect of 2 h versus conventional liposome preparations, consistent with the results of in vitro release experiments. In addition, in vitro cytotoxicity evaluations in RAW264.7 cells and in vivo evaluations revealed the biocompatibility and safety of the ropivacaine-sodium oleate ion-paired liposome (Rop-Ole-Lipo) system as a suitable local anesthetic for local pain management. Our findings provide a new idea for the preparation of local anesthetics.

Glutamate Chemical Exchange Saturation Transfer (GluCEST) Magnetic Resonance Imaging of Rat Brain With Acute Carbon Monoxide Poisoning.

ObjectivesTo evaluate the diagnostic and prognostic values of glutamate chemical exchange saturation transfer (GluCEST) magnetic resonance imaging as a quantitative method for pathogenetic research and clinical application of carbon monoxide (CO) poisoning-induced encephalopathy combined with the proton magnetic resonance spectroscopy (1H-MRS) and the related histopathological and behavioral changes.MethodsA total of 63 Sprague–Dawley rats were randomly divided into four groups. Group A (n = 12) was used for animal modeling verification; Group B (n = 15) was used for magnetic resonance molecular imaging, Group C (n = 15) was used for animal behavior experiments, and Group D (n = 21) was used for histopathological examination. All the above quantitative results were analyzed by statistics.ResultsThe peak value of carboxyhemoglobin saturation in the blood after modeling was 7.3-fold higher than before and lasted at least 2.5 h. The GluCEST values of the parietal lobe, hippocampus, and thalamus were significantly higher than the base values in CO poisoning rats (p < 0.05) and the 1H-MRS showed significant differences in the parietal lobe and hippocampus. In the Morris water maze tests, the average latency and distance were significantly prolonged in poisoned rats (p < 0.05), and the cumulative time was shorter and negatively correlated with GluCEST.ConclusionThe GluCEST imaging non-invasively reflects the changes of glutamate in the brain in vivo with higher sensitivity and spatial resolution than 1H-MRS. Our study implies that GluCEST imaging may be used as a new imaging method for providing a pathogenetic and prognostic assessment of CO-associated encephalopathy.

Rewarding and reinforcing effects of two dissociative-based new psychoactive substances, deschloroketamine and diphenidine, in mice

Dissociative-based new psychoactive substances (NPSs) are increasingly available through the Internet, and public health problems related to the recreational use of these substances have been increasing globally. Two such NPSs are deschloroketamine and diphenidine, which are primarily used recreationally as ketamine substitutes. However, there is little scientific evidence to describe the dependence liability of NPSs. This study aimed to evaluate the dependence liability of deschloroketamine and diphenidine via animal behavioral experiments. We evaluated the rewarding and reinforcing effects of these NPSs using the conditioned place preference (CPP) and the self-administration (SA) paradigms in mice. Psychomotor effects and behavioral features of these compounds were assessed by quantifying locomotor activity, stereotypic movements, and dopaminergic neurotransmission. Both deschloroketamine (10 mg/kg) and diphenidine (10–60 mg/kg) produced increased locomotor activation and stereotypy that were similar to the effects of ketamine (10 mg/kg). Both deschloroketamine (10 mg/kg) and diphenidine (10, 20 mg/kg) increased the animals' preference for the drug-paired compartment in the CPP testing. In the SA testing, deschloroketamine (1 mg/kg/infusion) increased the number of active lever presses and the number of infusions received, whereas diphenidine administration (1, 2 mg/kg/infusion) did not alter either of these. Furthermore, both deschloroketamine and diphenidine increased dopamine levels in PC-12 cells. Collectively, the data suggest that deschloroketamine may have both rewarding and reinforcing effects, whereas diphenidine only induced rewarding effect.

Involvement of Scratch2 in GalR1-mediated depression-like behaviors in the rat ventral periaqueductal gray

Galanin receptor1 (GalR1) transcript levels are elevated in the rat ventral periaqueductal gray (vPAG) after chronic mild stress (CMS) and are related to depression-like behavior. To explore the mechanisms underlying the elevated GalR1 expression, we carried out molecular biological experiments in vitro and in animal behavioral experiments in vivo. It was found that a restricted upstream region of the GalR1 gene, from -250 to -220, harbors an E-box and plays a negative role in the GalR1 promoter activity. The transcription factor Scratch2 bound to the E-box to down-regulate GalR1 promoter activity and lower expression levels of the GalR1 gene. The expression of Scratch2 was significantly decreased in the vPAG of CMS rats. Importantly, local knockdown of Scratch2 in the vPAG caused elevated expression of GalR1 in the same region, as well as depression-like behaviors. RNAscope analysis revealed that GalR1 mRNA is expressed together with Scratch2 in both GABA and glutamate neurons. Taking these data together, our study further supports the involvement of GalR1 in mood control and suggests a role for Scratch2 as a regulator of depression-like behavior by repressing the GalR1 gene in the vPAG.

Improved 3D tracking and automated classification of rodents' behavioral activity using depth-sensing cameras.

Analysis of rodents' behavior/activity is of fundamental importance in many research fields. However, many behavioral experiments still rely on manual scoring, with obvious problems in reproducibility. Despite important advances in video-analysis systems and computational ethology, automated behavior quantification is still a challenge. The need for large training datasets, background stability requirements, and reduction to two-dimensional analysis (impairing full posture characterization), limit their use. Here we present a novel integrated solution for behavioral analysis of individual rats, combining video segmentation, tracking of body parts, and automated classification of behaviors, using machine learning and computer vision methods. Low-cost depth cameras (RGB-D) are used to enable three-dimensional tracking and classification in dark conditions and absence of color contrast. Our solution automatically tracks five anatomical landmarks in dynamic environments and recognizes seven distinct behaviors, within the accuracy range of human annotations. The developed free software was validated in experiments where behavioral differences between Wistar Kyoto and Wistar rats were automatically quantified. The results reveal the capability for effective automated phenotyping. An extended annotated RGB-D dataset is also made publicly available. The proposed solution is an easy-to-use tool, with low-cost setup and powerful 3D segmentation methods (in static/dynamic environments). The ability to work in dark conditions means that natural animal behavior is not affected by recording lights. Furthermore, automated classification is possible with only ~30 minutes of annotated videos. By creating conditions for high-throughput analysis and reproducible quantitative measurements of animal behavior experiments, we believe this contribution can greatly improve behavioral analysis research.

Animals in Virtual Environments.

The core idea in an XR (VR/MR/AR) application is to digitally stimulate one or more sensory systems (e.g. visual, auditory, olfactory) of the human user in an interactive way to achieve an immersive experience. Since the early 2000s biologists have been using Virtual Environments (VE) to investigate the mechanisms of behavior in non-human animals including insects, fish, and mammals. VEs have become reliable tools for studying vision, cognition, and sensory-motor control in animals. In turn, the knowledge gained from studying such behaviors can be harnessed by researchers designing biologically inspired robots, smart sensors, and rnulti-agent artificial intelligence. VE for animals is becoming a widely used application of XR technology but such applications have not previously been reported in the technical literature related to XR. Biologists and computer scientists can benefit greatly from deepening interdisciplinary research in this emerging field and together we can develop new methods for conducting fundamental research in behavioral sciences and engineering. To support our argument we present this review which provides an overview of animal behavior experiments conducted in virtual environments.

Control of habitual instrumental actions by anticipation of postingestive sensations.

In animal behavioral experiments, extended training causes instrumental actions that deliver ingestible substances to lose sensitivity to outcome devaluation and contingency degradation, and to gain direct sensitivity to the current motivational state. These features of habitual control have been attributed to a process that relies on stimulus-response (S-R) associations linking the context to instrumental actions and Pavlovian associations linking the same context to orally-sensed properties of substances attained there. This Pavlovian process was conceived based on the results of irrelevant incentive experiments, but it is not supported by the results of all such experiments. An alternative process is therefore proposed here. In this process, recall of the instrumental action is evoked by an S-R association, but the rate at which this action is then performed is controlled by anticipation of postingestive sensations that have frequently followed it. This anticipation relies on recall of an association linking the action directly to the postingestive sensations. This association is learned during the formation of a chunked action series that begins with the instrumental action and ends with a consummatory response. It enables a prediction of subjective value that is directly influenced by the current motivational state, but is not influenced by devaluation or non-contingent delivery of the substance that has produced the postingestive sensations.

Abstract B51: Targeted nanoparticle approach to treating metastatic prostate cancer

Abstract Introduction: Treatment outcomes of bone metastatic prostate cancer remain poor despite an increasing number of therapeutic options approved in recent years. Limitations exist in the drugs that are approved, such as no overall survival benefits or serious dose-limiting toxicities. We have engineered a targeted nanoparticle (NP) system to deliver cabazitaxel to bone lesions. The amino-bisphosphonate, alendronate, was used as the bone-targeting moiety on the surface of the NP. The objective of this approach is to increase therapeutic payload at the site of bone metastasis to achieve an improved therapeutic index. Methods: Poly(lactic-co-glycolic acid) NPs were synthesized using a modified water-in-oil-in-water double-emulsion solvent evaporation technique followed by binding of alendronate to the surface of the NP. We characterized NPs for size and zeta potential using dynamic light scattering. Cabazitaxel encapsulation efficiency, drug loading, and release kinetics were optimized by quantification with HPLC analysis. In vitro cell viability studies were performed on C4-2B and PC3 prostate cancer cell lines. 3D prostate cancer spheroids were utilized as well to test cell viability and NP penetration. Ex vivo bone binding studies were used to test nanoparticle affinity for hydroxyapatite structure. In vivo tumor efficacy studies were carried out with male athymic nude mice implanted with intraosseous tumors consisting of PC3-luciferase cells. After bone tumors were established for 1 week, mice were treated via tail vein injection with either saline, free cabazitaxel, non-targeted NPs, or targeted NPs for one month (starting n=6 per group). Response was measured with in vivo bioluminescence imaging, tumor limb weight at conclusion of experiment, and mouse x-ray monitoring. In addition, animal behavior experiments were performed on all treatment groups to assess functional status through gait analysis and pain through von Frey filament assay. Results: NPs were successfully synthesized to mean size of 236 nm with a PDI of .120. Highest encapsulation of cabazitaxel into nanoparticle was 55.8% with a drug loading of 3.7%. Release kinetics showed a strong burst phase release over the first 8 hours and subsequent sustained release up to 72 hours. In vitro cell viability and 3D spheroid experiments showed targeted and nontargeted NP to be equivalent to free drug. Ex vivo bone binding experiment showed targeted NP had a 4-fold increase in binding to bone at 6 hours and an 8-fold increase in bone binding at 72 hours compared to nontargeted NP. Tumor efficacy experiment showed targeted NP and nontargeted NP had a statistically significant overall reduction in tumor measured by bioluminescence (P value &amp;lt; 0.005). Interestingly, mice treated with targeted NP had no bone lesions on x-ray, whereas 100% of mice in saline group, 100% of mice in cabazitaxel group, and 33% of mice in nontargeted NP group had bone lesions. Gait analysis did not show a statistically significant difference between groups. However, von Frey assay showed a significant reduction in relative response in the targeted NP group (P value &amp;lt; 0.005). Conclusion: We have successfully synthesized a bone-targeted NP system. In this project, we have shown that targeted NPs help maintain bone structure in tumor-burdened limbs as well as decrease tumor size. We have also shown that these targeted NPs reduce the relative response to von Frey filament pain stimulation in the tumor limb. This bone-targeted NP system is a promising potential therapeutic in developing improved treatments for bone-metastatic prostate cancer patients. Note: This abstract was not presented at the conference. Citation Format: Andrew Gdowski, Amalendu Ranjan, Marjana Sarker, Jamboor Vishwanatha. Targeted nanoparticle approach to treating metastatic prostate cancer [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr B51.

ToxTrac: A fast and robust software for tracking organisms

Abstract Behavioural analysis based on video recording is becoming increasingly popular within research fields such as; ecology, medicine, ecotoxicology and toxicology. However, the programs available to analyse the data, which are free of cost, user‐friendly, versatile, robust, fast and provide reliable statistics for different organisms (invertebrates, vertebrates and mammals) are significantly limited. We present an automated open‐source executable software (ToxTrac) for image‐based tracking that can simultaneously handle several organisms monitored in a laboratory environment. We compare the performance of ToxTrac with current accessible programs on the web. The main advantages of ToxTrac are as follows: (i) no specific knowledge of the geometry of the tracked bodies is needed; (ii) processing speed, ToxTrac can operate at a rate &gt;25 frames per second in HD videos using modern computers; (iii) simultaneous tracking of multiple organisms in multiple arenas; (iv) integrated distortion correction and camera calibration; (v) robust against false positives; (vi) preservation of individual identification; (vii) useful statistics and heat maps in real scale are exported in image, text and excel formats. ToxTrac can be used for high speed tracking of insects, fish, rodents or other species, and provides useful locomotor information in animal behavior experiments. Download ToxTrac here: https://toxtrac.sourceforge.io (Current version v2.61).