Limited evidence for learning in a shuttle box paradigm in crickets (Acheta domesticus)

Aversive learning has been studied in a variety of species, such as honey bees, mice, and non-human primates. Since aversive learning has been found in some invertebrates and mammals, it will be interesting to know if this ability is shared with crickets. This paper provides data on aversive learning in male and female house crickets (Acheta domesticus) using a shuttle box apparatus. Crickets are an ideal subject for these experiments due to their well-documented learning abilities in other contexts and their readily quantifiable behaviors. The shuttle box involves a two-compartment shock grid in which a ‘master’ cricket can learn to avoid the shock by moving to specific designated locations, while a paired yoked cricket is shocked regardless of its location and therefore cannot learn. Baseline control crickets were placed in the same device as the experimental crickets but did not receive a shock. Male and female master crickets demonstrated some aversive learning, as indicated by spending more time than expected by chance in the correct (no shock) location during some parts of the experiment, although there was high variability in performance. These results suggest that there is limited evidence that the house crickets in this experiment learned how to avoid the shock. Further research with additional stimuli and other cricket species should be conducted to determine if house crickets and other species of crickets exhibit aversive learning.

Maternal Neu5Ac Supplementation During Pregnancy Improves Offspring Learning and Memory Ability in Rats

Sialic acids are postulated to improve cognitive abilities. This study aimed to evaluate the effects of sialic acid on behavior when administered in a free form as N-acetylneuraminic acid (Neu5Ac) to pregnant mothers or rat pups. The experiment involved 40 male 21-day-old rat pups and 20 15-day-pregnant rats that were randomized into four Neu5Ac treated groups: 0 (control), or 10, 20, and 40 mg/kg. Morris water maze test and shuttle box test were performed on the rat pups and maternal Neu5Ac-supplemented offspring on day 100 to evaluate their cognitive performance. The Neu5Ac levels in the cerebral cortex and hippocampus were tested with high-performance liquid chromatography-fluorescence detection (HPLC-FLD). We found that the maternal Neu5Ac-supplemented offspring showed better cognitive performance, less escape latency in the Morris water maze test, and less electric shock time shuttle box test, compared with the untreated control. In the meantime, the Neu5Ac level in the cerebral cortex and hippocampus of the offspring was higher in the Neu5Ac treatment group than that in the untreated control group. However, no significant differences were observed between rat pups in the treated and the untreated control groups in terms of cognitive performance and Neu5Ac content in the cerebral cortex and hippocampus. Maternal Neu5Ac supplementation during pregnancy could effectively promote the brain Neu5Ac content of the offspring and enhance their cognitive performance, but Neu5Ac had no such effect on rat pups while directly supplemented with Neu5Ac.

A Modified Two-Way Active Avoidance Test for Combined Contextual and Auditory Instrumental Conditioning

Available two-way active avoidance paradigms do not provide contextual testing, likely due to challenges in performing repetitive trials of context exposure. To incorporate contextual conditioning in the two-way shuttle box, we contextually modified one of the chambers of a standard two-chamber rat shuttle box with visual cues consisting of objects and black and white stripe patterns. During the 5 training days, electrical foot shocks were delivered every 10 s in the contextually modified chamber but were signaled by a tone in the plain chamber. Shuttling between chambers prevented an incoming foot shock (avoidance) or aborted an ongoing one (escape). During contextual retention testing, rats were allowed to freely roam in the box. During auditory retention testing, visual cues were removed, and tone-signaled shocks were delivered in both chambers. Avoidance gradually replaced escape or freezing behaviors reaching 80% on the last training day in both chambers. Rats spent twice more time in the plain chamber during contextual retention testing and had 90% avoidance rates during auditory retention testing. Our modified test successfully assesses both auditory and contextual two-way active avoidance. By efficiently expanding its array of outcomes, our novel test will complement standard two-way active avoidance in mechanistic studies and will improve its applications in translational research.

The Effect of Co-Administration of Portulaca Oleracea and Plantago Psyllium Plus Submaximal Swimming Training on Memory Deficit in Streptozotocin/Nicotinamide-Induced Type 2 Diabetic Rats

Many studies have assessed the effect of exercise training and the use of various herbs on the cognitive deficit in type-2 diabetic patients. The aim of the current study was to assess the effect of a combination of two traditional plants, Portulaca oleracea and Plantago psyllium, and swimming training on cognitive decline in type 2 diabetic rats. Fifty male Wistar rats (weight: 275±25g) were selected. Type-2 diabetes was induced by a single IP injection of streptozotocin and nicotinamide. Then, the subjects were randomly assigned to the following groups: control-healthy (Con), control-diabetic (D), diabetic-training (D+Tr), diabetic-P.oleracea plus P. psyllium (D+PO+PP), and diabetic- P.oleracea plus P. psyllium plus training groups (D+PO+PP+Tr). Training groups were subjected to submaximal swimming training for 12 weeks (5 days per week). Learning abilities and memory retention were evaluated using shuttle box, elevated plus maze, open field, and novel recognition object tests. Step-through latency period in retention phase in the shuttle box test and discrimination index in the novel recognition object test increased in response to the simultaneous use of two herbal medicines. Swimming training had no effect on learning and memory indices in diabetic rats, but co-administration of P. oleracea and P. psyllium with swimming training for 12 weeks ameliorated passive avoidance memory, general locomotor activity, and exploratory behavior in diabetic rats. These results indicated that co-administration of P. oleracea and P. psyllium with submaximal swimming training for 12 weeks can reverse the cognitive impairment present in type-2 diabetic rats.

Evaluating tank acclimation and trial length for dynamic shuttle box temperature preference assays in aquatic animals

Characterizing the thermal preference of fish is important in conservation, environmental and evolutionary physiology and can be determined using a shuttle box system. Initial tank acclimation and trial lengths are important considerations in experimental design, yet systematic studies of these factors are missing. Three different behavioral assay experimental designs were tested to determine the effect of tank acclimation and trial length (12:12, 0:12, 2:2; hours of tank acclimation: behavioral trial) on the temperature preference of juvenile lake whitefish (Coregonus clupeaformis), using a shuttle box. Average temperature preferences for the 12:12, 0:12, and 2:2 experimental designs were 16.10±1.07°C, 16.02±1.56°C, 16.12±1.59°C respectively, with no significant differences between experimental designs (p= 0.9337). Ultimately, length of acclimation time and trial length had no significant effect on thermal preference.

A study of effect of Centella asiatica on oxidative markers in the hippocampus of offsprings born to alcohol-fed pregnant rats and the correlation with their cognitive functions

Objectives Alcohol consumption causes several harmful effects on the organs, which is hugely understated. Many deformities occur in the fetus when pregnant mothers indulge in alcoholism. Alcohol is a known teratogen, hence organ formation, particularly development of parts brain critical for cognitive function may be affected. The oxidative brain damage also could contribute to reduced cognitive efficiency of brain exposed to alcohol. In this study, effect of Centella asiatica in relieving the oxidative brain damage in offspring of alcohol fed mother rats was evaluated. Methods In this study we fed alcohol (5 g/kg body weight, 30% w/v) to a group of pregnant Wistar rats during gestation period, and another group served as control. Four groups of rats (n = 6 each) were selected from the offspring of these mother rats. The groups were, control, positive (treated) control, untreated and treated from alcohol-fed mother. Their cognitive parameters were tested in water maze, shuttle box and compared. Further their oxidative status was evaluated by estimating malondialdehyde (MDA), protein carbonyl, total antioxidants and glutathione reductase (GSH) in hippocampus. Results The results suggested that there was significantly high cognitive performance in maze test and shuttle box memory retention in rats treated with C. asiatica water extract and the antioxidant levels were high in their hippocampus. Conclusions The outcome of the study suggested that C. asiatica produced beneficial effects in reversing the alcohol induced brain damage in pregnancy.

The weakly electric fish, Apteronotus albifrons, actively avoids experimentally induced hypoxia

Anthropogenic environmental degradation has led to an increase in the frequency and prevalence of aquatic hypoxia (low dissolved oxygen concentration, DO), which may affect habitat quality for water-breathing fishes. The weakly electric black ghost knifefish, Apteronotus albifrons, is typically found in well-oxygenated freshwater habitats in South America. Using a shuttle-box design, we exposed juvenile A. albifrons to a stepwise decline in DO from normoxia (> 95% air saturation) to extreme hypoxia (10% air saturation) in one compartment and chronic normoxia in the other. On average, A. albifrons actively avoided the hypoxic compartment below 22% air saturation. Hypoxia avoidance was correlated with upregulated swimming activity. Following avoidance, fish regularly ventured back briefly into deep hypoxia. Hypoxia did not affect the frequency of their electric organ discharges. Our results show that A. albifrons is able to sense hypoxia at non-lethal levels and uses active avoidance to mitigate its adverse effects.

Effects of Flavonoids from Scutellaria Baicalensis Georgi Stems and Leaves on Learning and Memory Ability of APP/PS1 Transgenic Mice

Introduction: APP/PS1 transgenic mice are established natively AD-like animal model. The present study used this animal model to study the effects of stems and leaves flavonoids from Scutellaria baicalensis Georgi (SSF) on APP/PS1 transgenic mice learning and memory ability with Morris water maze, jumping platform, dark box and shuttle box test. The results demonstrated that SSF markedly improve the learning and memory ability in APP/PS1 transgenic mice, and the four behavioral tests of Morris water maze, jumping platform, dark box and shuttle box are also suitable methods for evaluating the learning and memory ability of animals. Objective: To study the effects of SSF on the learning and memory ability in APP/PS1 transgenic mice by several behavioral experiment methods. Methods: APP/PS1 transgenic mice were randomly divided into model group and three doses of SSF treated groups. While, the same period C57BL/6J mice were used as the control group. The APP/PS1 transgenic mice in the drug group were given continuous daily and orally administration of 50, 100 and 200 mg/kg SSF for 77 days. On the day 51 of administration, four behavioral experimental methods, including Morris water maze, jumping platform, dark box and shuttle box were supplied to test the learning and memory ability of all mice and continually administered SSF during the test. Results: Compared with the control group, Morris water maze test found that model group mice had a significant longer latency to find the hidden platform, shortened swimming time in the target quadrant, and reduced number of crossing platforms (P<0.05, P<0.01). The detection of jumping platform and dark box showed that the latencies of the model group for jumping off the platform and entering the dark box were significantly shortened, and error times received by electric shocks was significantly increased (P<0.05, P<0.01). The shuttle box test reported that the number of active avoidance in the model group was significantly decreased, while the times of passive avoidance and non-response were significantly increased (P<0.05, P< 0.01). However, the three doses of SSF markedly shortened or prolonged the latency of APP/PS1 transgenic mice to find the hidden platform, jump off the platform and enter the dark box, as well as reduce the errors times of electric shock (P<0.05, P<0.01). Conclusion: SSF can improve the learning and memory impairment of APP/PS1 mice by different behavioral test.

Modeling of the two shuttle box system within the internal logistics system using simulation software

The efficiency and effectiveness of the production system are influenced by the logistical arrangement of material flows. The smooth production, especially for assembly lines in the required quantity and at the required time (JIT or JIS systems), is currently ensured by automatically controlled towing sets (logistics trains), which consist of a tractor and several trucks. Another factor that affects the smooth production of assembly lines is the system of controlling the circulation of transport units. The number of transport units used in combination with the transport system significantly affects the efficiency of assembly workplaces. This article presents an analysis of the supply of assembly workplaces using a system of two shuttle boxes. The aim of this article is to investigate the influence of transport speed and capacity on the smoothness of the assembly process. Within the described analysis, the transport of 50,000 components is analyzed using a simulation model, while the length of the transport route is 32 km and 65 transport units per shift are used.