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Many species are able to recognize objects, but it has been proven difficult to pinpoint and compare how different species solve this task. Recent research suggested to combine computational and animal modelling in order to obtain a more systematic understanding of task complexity and compare strategies between species. In the present study, we created a large multidimensional stimulus set and designed a visual categorization task partially based upon modelling with a convolutional deep neural network (cDNN). Experiments included rats (N = 11; 1115 daily sessions in total for all rats together) and humans (N = 50). Each species was able to master the task and generalize to a variety of new images. Nevertheless, rats and humans showed very little convergence in terms of which object pairs were associated with high and low performance, suggesting the use of different strategies. There was an interaction between species and whether stimulus pairs favoured early or late processing in a cDNN. A direct comparison with cDNN representations revealed that rat performance was best captured by late convolutional layers while human performance related more to the higher-up fully connected layers. These findings highlight the additional value of using a computational approach for the design of object recognition tasks. Overall, this computationally informed investigation of object recognition behaviour reveals a strong discrepancy in strategies between rodent and human vision.

Face categorization and generalization and behavioral templates in rats

Background: Kidney is an essential excretory organ of our body. It can be damaged by poisonous effect of chemicals, toxin, prolonged and uncontrolled use of drugs. Aloe vera is a herbal plant, it can be used for the prevention and treatment of kidney damage due to its natural compatability. Objective: To observe the nephroprotective effect of Aloe vera against gentamicin induced nephrotoxicity in long evans male rats. Method: This experimental study was conducted in the Department of Physiology, Sir Salimullah Medical College (SSMC), Dhaka from 1st January 2018 to 30th December 2018. For this, forty five (45) apparently healthy long evans male rats, 90-120 days old, weighing between 150-200 g were taken and divided into control group (group A) and experimental group (group B - Aloe vera pretreated and gentamicin treated group). Control group was subdivided into group A1 (baseline control group) and group A2 (gentamicin treated control group). Each group consisted of fifteen (15) rats. At the beginning of the study period initial body weight of rats were measured at day 01. All the rats received basal diet for thirty (30) days. Group A1 received only basal diet for 30 consecutive days (started from day 1 to day 30). In addition to basal diet, group A2 received injection gentamicin intraperitoneally once daily in the morning (80 mg/kg/day) for last 5 days (26th to 30th) of the study period. Again, in addition to basal diet, experimental group received Aloe vera orally (200 mg/kg/day) for 30 days and injection gentamicin intraperitoneally (80 mg/kg/day) for last 5 days (26th to 30th). After measuring final body weight all the rats were sacrificed on day 31. Blood sample was collected from heart. Serum levels of creatinine and urea were estimated for assessment of kidney function. Statistical analysis was done by one way ANOVA test followed by post hoc-Bonferroni test. Result: Mean serum levels of creatinine and urea were significantly (p

Theta rhythms temporally coordinate sequences of hippocampal place cell ensembles during active behaviors, while sharp wave-ripples coordinate place cell sequences during rest. We investigated whether such coordination of hippocampal place cell sequences is disrupted during error trials in a delayed match-to-place task. As a reward location was learned across trials, place cell sequences developed that represented temporally compressed paths to the reward location during the approach to the reward location. Less compressed paths were represented on error trials as an incorrect stop location was approached. During rest periods of correct but not error trials, place cell sequences developed a bias to replay representations of paths ending at the correct reward location. These results support the hypothesis that coordination of place cell sequences by theta rhythms and sharp wave-ripples develops as a reward location is learned and may be important for the successful performance of a spatial memory task., Here the authors compare place cell sequence coding during correct and error trials in a spatial memory task. Sequences coded paths that were longer and more temporally compressed during correct trials and developed a bias to replay paths to a goal location during rest periods of correct but not error trials.

How do we learn about what to learn about? Specifically, how do the neural elements in our brain generalize what has been learned in one situation to recognize the common structure of – and speed learning in – other, similar situations? We know this happens; we and our mammalian kith become better at solving new problems – learning and deploying schemas 1–5 – as we go through life. However, we have little insight into this process. Here we show that using prior knowledge to facilitate learning is accompanied by the evolution of a neural schema in the orbitofrontal cortex (OFC). Single units were recorded from rats deploying a schema to learn a succession of odor sequence problems. With learning, OFC ensembles converged on a low-dimensional neural manifold across both problems and subjects; this manifold represented the common structure of the problems and its evolution accelerated across their learning. These results demonstrate the formation and use of a schema in a prefrontal brain region to support a complex cognitive operation. Our results not only reveal an important new role for the OFC in learning but also have significant implications for using ensemble analyses to tap into complex cognitive functions.

Background: Kalmishak has some ability of removal of inorganic matter. Objective: The purpose of the present study was to see the ability of Kalmishak for the removal of arsenic from isolated liver tissues of rat. Methodology: This animal study was carried out on isolated liver tissues of Long Evans Norwegian adult healthy male rats weighing 160 to 200 g. The rats were 3 to 6 months of age obtained from animal house of Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from 2004 to 2005. Measurements and all tasks were performed in a very careful manner. Atomic Absorption Spectrophotometer with Hydride Generator was used to measure the arsenic level. No arsenic was added in test tube I. 2.5 g/ml arsenic trioxide was added rest of the test tubes. They all were incubated for 45 minutes at 370C. Then the tissues were washed properly. In second incubation, different extracts of kalmishak (C 1and C 2) were added at 20 l/ml dose. Second incubation was also for another 45 minutes at 370C. There were duplicates of all test tubes. Result: When the tissues were incubated with no arsenic in both 1st and 2nd incubation the amount of arsenic was found 6.62 ± 3.40 μg / g (mean ± s.e) of protein and it was considered as blank. The liver tissues of rat loaded with 2.5 μg / ml arsenic were incubated for 45 minutes at 37°C with no extract and the amount of arsenic was 98.32 ± 36.10 μg / g (mean ± s.e) of protein and the value was considered as standard. The blank value was then deducted from the standard and the derived value was considered as control. After exposure with Compound -1 (20 μl /ml) in second incubation for 45 minutes at 37°C, the amount of arsenic was 69.57 ± 7.60 μg / g (mean ± s.e) of protein. There was 13.00% removal of arsenic. Conclusion: In conclusion Kalmishak has the ability to remove of arsenic from isolated liver tissues of rat. Journal of Current and Advance Medical Research 2020;7(2): 55-59

Our previous studies used type-2 diabetic model Otsuka Long-Evans Tokushima fatty (OLETF) rats, and showed that both exercise and diet regimen decreased body weight (BW) and improved glucose intolerance (GI), and dyslipidemia. However, exercise regimenwas also associated with increased blood pressure (BP), diabetic nephropathy (DN) progression characterized by an increase in urinary albumin excretion (UAlb), and morphological abnormalities of the kidneys. This study examined the effects of an exercise regimen alone and the combined treatment of exercise and an antihypertensive medication, captopril (Capt), on systemic BP, DN progression, BW, GI, and dyslipidemia in OLETF rats. Twenty-four male OLETF rats were divided into the following groups: voluntary exercise alone (OLETF-Ex), Capt administration alone (OLETF-Capt), Capt and exercise (OLETF-Capt & Ex), and sedentary control (OLETF-Sed) groups. Six male Long-Evans Tokushima Otsuka (LETO) rats were used as a normal sedentary control (LETO-Sed). These treatments were conducted from 21 to 30 weeks of age. Approximately 20 mg/kg/day of Capt was administered daily. After the treatment, the OLETF-Ex group experienced decreased BW and improved GI and dyslipidemia; however, it was associated with diastolic BP elevation and DN progression. The OLETF-Capt group experienced decreased BP and serum TG concentration and inhibited DN progression. The OLETF-Capt & Ex group experienced decreased BW and BP, and improved GI and dyslipidemia without the progression of DN. This study demonstrated that a combined treatment of exercise and antihypertensive agents, such as Capt, is recommended as an ideal regimen for hypertensive diabetic patients in the pre-nephropathy stage to avoid DN progression induced by an exercise regimen alone.

The role of the hippocampus in goal-directed action is currently unclear; studies investigating this issue have produced contradictory results. Here we reconcile these contradictions by demonstrating that, in rats, goal-directed action relies on the dorsal hippocampus, but only transiently, immediately after initial acquisition. Furthermore, we found that goal-directed action also depends transiently on physical context, suggesting a psychological basis for the hippocampal regulation of goal-directed action control.

We report here studies to determine whether, and if so, how, the neuronal support for behavior depends on the number of training steps presented in the history of its formation. A training step is the formation of a new skill consisting of a sequence of behavioral acts whose execution leads to achievement of a result: receipt of food. Rats (Long Evans) were trained to an operant pedal-pressing food-procuring skill using two methods – with one or several stages – and the activity of individual neurons in the retrosplenial dysgranular area of the cortex was recorded. In the group of rats in which the skill was acquired in four steps (multistep), there were significantly more neurons specialized for approach and pedal-pressing (consistently activated during these acts) and the mean firing frequency of neurons with structured but not necessarily consistent activity in the learned behavior was greater; there were also more clusters combining cells with selectively increased activity in the same sets of behavioral acts. In animals trained in a single step, only two neurons specialized for approach and pedal-pressing were seen, though there were more cells with structured activity in behavior, these cells displaying maximum firing frequencies in these acts. Thus, the different number of stages in the history of learning the same operant skill was linked with significant differences in the relative number and pattern of activity of two categories of retrosplenial cortex (RC) neurons: those specialized relative to the acts of the learned behavior and cells with structured but variable activity.

Currently, diabetes mellitus type two is a public health challenge worldwide. Even though there are many oral hypoglycemic agents, a large part of the population continues to use herbal remedies with proven benefits. However, there are few works aimed at evaluating combinations of drugs and herbal remedies. These combinations of drugs and herbal substances can lead to a decrease in the therapeutic effect of each of them. The present work was designed to evaluate the combination of Metformin with aqueous extracts of chaya (Cnidoscolus aconitifolius) in a group of Long Evans streptozotocin-induced diabetes rats. Several combinations of aqueous extracts of C. aconitifolius and Metformin were tested and glycemia was measured in streptozotocin-induced diabetes rats. Additionally, the chemical profile of the extracts was determined by high performance liquid chromatography coupled mass tandem detector (HPLC-MS / MS). Results revealed that the combinations tested suggested an antagonistic effect between both compounds since the glycemia remained high in three of the four treated groups. Some of the compounds detected in chaya extracts by HPLC-MS/MS could give a clue of the explanation of this behavior. Conclusively, the therapeutic effect of Metformin may decrease when chaya is regularly consumed as a complementary herbal remedy, as used in a part of the Mexican population. It is recommended to deepen in the future in the pharmacodynamic part to explain this behavior. Key words: Chaya, Metformin, diabetes, antagonistic effect.

In males of a variety of species, administration of progesterone during adulthood has been shown to decrease the expression of consummatory sexual behaviors and androgen receptors. However, it remains to be determined if the progesterone-induced decrease in androgen-receptor signaling and consummatory sexual behaviors correspond with less of a preference for a sexually receptive female relative to another male, a behavioral phenotype indicative of sexual motivation. Consistent with the effects of progesterone reported in males of other species, progesterone-treated rats, relative to vehicle-treated rats, exhibited fewer intromissions and ejaculations. Correspondingly, the weights of the androgen sensitive bulbourethral glands were lighter in progesterone-treated rats. In addition, unlike vehicle-treated rats, progesterone-treated rats did not exhibit a preference for a female rat during the early stages of testing. However, across the entire test, both treatment groups exhibited a preference for a female rat, and consequently, there were no differences between the conditions in overall sexual motivation. Progesterone treatment did not alter activity or anxiety-like behaviors. The results of the current study suggest that the lower levels of androgen-receptor signaling and consummatory sexual behaviors in males following progesterone treatment are associated with a transient deficit in the preference for a female sexual incentive.

Nearly all species rely on visual and nonvisual cues to guide navigation, and which ones they use depend on the environment and task demands. The postsubiculum (PoS) is a crucial brain region for the use of visual cues, but its role in the use of self-movement cues is less clear. We therefore evaluated rats' navigational performance on a food-carrying task in light and in darkness in rats that had bilateral neurotoxic lesions of the PoS. Animals were trained postoperatively to exit a refuge and search for a food pellet, and carry it back to the refuge for consumption. In both light and darkness, control and PoS-lesioned rats made circuitous outward journeys as they searched for food. However, only control rats were able to accurately use visual or self-movement cues to make relatively direct returns to the home refuge. These results suggest the PoS's role in navigation is not limited to the use of visual cues, but also includes the use of self-movement cues. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Numerous examples in the decision-making literature demonstrate that animals sometimes make choices that are not in their long-term best interest. One particular example finds pigeons preferring a low-probability alternative in lieu of a high-probability alternative, referred to as suboptimal choice. Although there is ample evidence that pigeons engage in such suboptimal choice, there is currently weak evidence (at best) that rats also do so. Cunningham and Shahan's (2018) temporal information-theoretic model suggests that suboptimal choice in pigeons arises when (1) the low-probability alternative provides stimuli that convey more temporal information than stimuli associated with the high-probability alternative and (2) when the delay to food is much longer relative to the delay to temporally informative signals at the choice point. The latter condition plays the important role of biasing decision making to be governed by the relative temporal information conveyed by stimuli rather than the relative rate of food delivery. The present experiment explored the possibility that rats will engage in suboptimal choice if the delay to food at the choice point is sufficiently long, as the temporal information-theoretic model suggests. Rats were given a choice between a suboptimal alternative providing food 20% of the time and an optimal alternative providing food 50% of the time. The suboptimal alternative provided stimuli that differentially signaled choice outcomes whereas the optimal alternative did not. The postchoice delay was manipulated across conditions and ranged from 10 s to 50 s. As with previous research, rats did not engage in suboptimal choice when the postchoice delay was 10 s. However, once the delay was at least 30 s, rats engaged in suboptimal choice. These results are consistent with the temporal information-theoretic model of suboptimal choice and suggest that rats and pigeons likely do not differ in the decision-making processes involved in the suboptimal choice procedure. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

It is tempting to equate the automatization of an action sequence with the formation of a habit. However, the term “habit” specifically implies a failure to evaluate future consequences to guide behavior. To test if automatized sequences become habitual, we trained rats on an action sequence task for either 20 or 60 d and then conducted reward devaluation tests. While both groups showed equivalent goal-directed performance of the trained action sequence on a global measure of behavior, sequence initiation and completion times were differentially sensitive to outcome devaluation in moderately and extensively trained rats.

Hippocampal theta oscillations in rodents profoundly impact neural activity, spatial coding, and synaptic plasticity and learning. What are the sensory mechanisms governing slow oscillations? We hypothesized that the nature of multisensory inputs is a crucial factor in hippocampal rhythmogenesis. We compared the rat hippocampal slow oscillations in the multisensory-rich real world (RW) and in a body-fixed, visual virtual reality (VR). The amplitude and rhythmicity of the hippocampal ~8 Hz theta were enhanced in VR compared to RW. This was accompanied by the emergence of a ~4 Hz oscillation, termed the eta rhythm, evident in the local field potential (LFP) in VR, but not in RW. Similar to theta, eta band amplitude increased with running speed in VR, but not in RW. However, contrary to theta, eta amplitude was highest in the CA1 cell layer, implicating intra-CA1 mechanisms. Consistently, putative CA1 interneurons, but not pyramidal neurons, showed substantially more eta modulation in VR than in RW. These results elucidate the multisensory mechanisms of hippocampal rhythms and the surprising effects of VR on enhancing these rhythms, which has not been achieved pharmacologically and has significant broader implications for VR use in humans.One Sentence SummaryNavigation in virtual reality greatly enhances hippocampal 8Hz theta rhythmicity, and generates a novel, ~4Hz eta rhythm that is localized in the CA1 cell layer and influences interneurons more than pyramidal neurons.

Experimental research controls for past experience, yet prior experience influences how we learn. Here, we tested whether we could recruit a neural population that usually encodes rewards to encode aversive events. Specifically, we found that GABAergic neurons in the lateral hypothalamus (LH) were not involved in learning about fear in naive rats. However, if these rats had prior experience with rewards, LH GABAergic neurons became important for learning about fear. Interestingly, inhibition of these neurons paradoxically enhanced learning about neutral sensory information, regardless of prior experience, suggesting that LH GABAergic neurons normally oppose learning about irrelevant information. These experiments suggest that prior experience shapes the neural circuits recruited for future learning in a highly specific manner, reopening the neural boundaries we have drawn for learning of particular types of information from work in naive subjects. Sharpe et al. find that prior reward-learning experience can prime reward circuits to encode fear memories. This suggests prior experience can shape the way we learn, opening the neural boundaries for learning about particular types of information.

The ventral pallidum (VP) is anatomically poised to contribute to threat behavior. Recent studies report a VP population that scales firing increases to reward but decreases firing to aversive cues. Here, we tested whether firing decreases in VP neurons serve as a neural signal for relative threat. Single-unit activity was recorded while male rats discriminated cues predicting unique foot shock probabilities. Rats’ behavior and VP single-unit firing discriminated danger, uncertainty, and safety cues. Two populations of VP neurons dynamically signaled relative threat, decreasing firing according to foot shock probability during early cue presentation, but disproportionately decreasing firing to uncertain threat as foot shock drew near. One relative threat population increased firing to reward, consistent with a bi-directional signal for general value. The second population was unresponsive to reward, revealing a specific signal for relative threat. The results reinforce anatomy to reveal the VP as a neural source of a dynamic, relative threat signal., Moaddab et al. monitored single-unit firing of ventral pallidum (VP) neurons alongside behavior in rats when presented with auditory cues of various threat levels. They show that the VP is comprised of functional neuronal populations that dynamically respond to threat and thus constitute a neural basis for threat behaviors.

Previous research has implicated the ventral pole of the hippocampus in regulating anxiety. However, most rat studies examining the specific contribution of the ventral hippocampus have utilized techniques that have nonspecific effects and/or create nonreversible damage to the region. The present study sought to characterize the role of ventral hippocampal CaMKIIα-expressing neurons in modulating anxiety- and fear-like behavior during exposure to a variety of threatening stimuli. Five weeks prior to testing, adult male Long-Evans hooded rats received ventral hippocampal viral-vector infusions expressing either AAV8-CaMKIIα-hM4D-mCherry (DREADD) or AAV8-CaMKIIα-EGFP (GFP). DREADD transfection allowed for the specific, noninvasive and temporary inhibition of the ventral hippocampus (vHC) immediately before threat presentation. Rats were evaluated for behaviors congruent with anxiety- or fear-like defensive states during testing in the elevated plus-maze (EPM) and light-dark test (LDT), or post footshock freezing and footshock-induced contextual freezing, respectively. Analyses revealed a significant effect of vHC inhibition that was dependent on the type of threat exposure. Specifically, DREADD-induced silencing of vHC neurons reduced anxiety-like behavior in the EPM and LDT, without reliably affecting footshock-induced fear. These data add to a growing literature implicating the vHC as a key region involved in controlling the expression of anxiety in rodents, primates and humans.

Neurons in hippocampal output area CA1 are thought to exhibit redundancy across cortical and hippocampal inputs. Here we show instead that acute silencing of CA3 terminals drastically reduces place field responses for many CA1 neurons, while a smaller number are unaffected or have increased responses. These results imply that CA3 is the predominant driver of CA1 place cells under normal conditions, while also revealing heterogeneity in input dominance across cells.

Multiline slot machines encourage continued play through 'losses disguised as wins' (LDWs), outcomes in which the money returned is less than that wagered. Individuals with gambling problems may be susceptible to this game feature. The cognitive and neurobiological mechanisms through which LDWs act are unknown. In a novel rat operant task, animals chose between a 'certain' lever, which always delivered two sugar pellets, or an 'uncertain' lever, resulting in four sugar pellets on 50% of trials. LDWs were then introduced as a return of three sugar pellets on 30-40% of uncertain rewarded trials. For half the rats, winning outcomes were paired with audiovisual feedback (cues). In a second study, the basolateral amygdala (BLA) was inactivated during initial presentation of LDWs. While LDWs shifted most rats' choice toward the certain lever, a subgroup of LDW vulnerable rats continued to choose the uncertain option, when the reward rate diminished. This profile of LDW vulnerability was reproduced after inactivating the BLA. Persistent choice of uncertain outcomes despite lower reward rates may reflect impaired functioning within the BLA. Future work using this model may provide insight into the neurobiological mechanisms contributing to the motivational properties of LDWs and their contribution to problematic gambling.

We previously demonstrated that 40 days of prior midlife estradiol treatment results in enhanced spatial memory in aging ovariectomized rats long after termination of the estradiol treatment. Our current goal was to determine whether this benefit is due to lasting impacts on memory specifically of previous exogenous estradiol treatment or simply due to delaying cognitive deficits that occur following loss of ovarian hormones. Middle-aged rats were ovariectomized or underwent sham surgery. Ovariectomized rats received estradiol (Previous Estradiol) or vehicle (Previous Vehicle) implants. Rats undergoing sham surgery (Previous Intact) received vehicle implants. Forty days later, Previous Intact rats were ovariectomized, the other 2 groups underwent sham surgeries, and all implants were removed. Thus, no ovarian or exogenously administered hormones were present during behavior testing. Rats underwent 24 days of acquisition training on an 8-arm radial maze. Following acquisition and again 2 months later, rats were tested on delay trials, during which animals had to remember the location of food rewards across time delays inserted between fourth and fifth arm choices. During acquisition, rats that had previous extended exposure to exogenous estradiol (Previous Estradiol) and endogenous ovarian hormones (Previous Intact) significantly outperformed rats that did not experience extended hormone exposure (Previous Vehicle). However, during delays trials the Previous Estradiol group significantly outperformed both the Previous Vehicle and Previous Intact groups. Results demonstrate that whereas extended exposure to endogenous ovarian hormones may provide short-term cognitive benefits, midlife estradiol treatment following ovariectomy provides additional benefits that persist for months following termination of treatment. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Extracts of ginseng species show antihyperglycemic activity. We evaluated the inhibitory effects of diabetic complications for Korean Red Ginseng (KRG), which is enriched in ginsenosides using Otsuka Long-Evans Tokushima Fatty (OLETF) rats. The animals were divided into one of four groups (n = 6∼9): Long–Evans–Tokushima–Otsuka rats (control rats), OLETF rats, rats given 200 mg/kg KRG, and rats given 400 mg/kg KRG. We examined the protective potential of KRG against type 2 diabetic illnesses. The results exhibited that KRG showed significant antihyperglycemic and antioxidative effects in KRG-treated OLETF rats. And, our results proposed the amelioration of cardiac function through normalized ejection fraction, fractional shortening, and vascular reactivity. Furthermore, histopathological abnormalities in the OLETF rats were prevented by KRG treatment. Keywords: hemodynamics, Korean Red Ginseng, Protection, Type 2 diabetes, vesicular function

Stress during development can shift the typical developmental trajectory. Maternal stress prior to conception has recently been shown to exert similar influences on the offspring. The present study questioned if a consistent maternal stressor prior to conception (elevated platform stress) would impact the pre-weaning development of offspring brain and behavior, and if maternal care was vulnerable to this experience. Adult female Long–Evans rats were subjected to elevated platform stress for 27 days prior to mating with non-stressed males. Maternal care was monitored, and pups were assessed in two tests of early behavioral development, negative geotaxis and open field. Pups were perfused at weaning and their brains were extracted and stained with Cresyl Violet, allowing gross measurements of cortical and subcortical structures and estimates of neuron density. Main findings indicate that a change in prefrontal cortical thickness is evident despite no change in maternal care. Female offspring show a decrease in medial-dorsal thalamus size. The current study failed to find an effect of maternal preconception stress on early behavioral development. These results suggest that the PFC, and likely behavior dependent on the PFC, is vulnerable to maternal preconception stress and that a strong sex effect is evident. Further studies should examine how such offspring fare using a lifespan model and investigate potential mechanisms responsible for these effects.

The study was undertaken to investigate the effects of Spirulina platensis on body weight, blood glucose and lipid profile on alloxan induced diabetic rats. Fifteen Long Evans male rats at six weeks of age were used for the experiment. Diabetes was induced by intraperitoneal injection of alloxan@ 150 mg/kg and experiment was carried out for a period of 6 weeks. Rats were divided into three groups of 5 rats each. The groups were i)healthy control, ii) diabetic control with both receiving rats’ pellet as supplement, and iii) diabetic treated with oral administration of Spirulina platensis @ 400 mg/kg bwt. Results from the study showed that Spirulina platensis reduced blood glucose significantly ( P< 0.01) and increased body weight significantly (P< 0.05) in contrast to diabetic control group after 6 weeks. Lipid profile analysis with Spirulina platensis @ 400 mg/kg showed that total cholesterol, plasma triglycerides, and LDL were lowered significantly compared to diabetic groups in contrast to HDL levels which were increased following the use of Spirulina platensis . Our findings showed that oral administration of Spirulina platensis could reduce the adverse effect of alloxan induced diabetes in rats. Based on this research it can be concluded that Spirulina platensis has antihyperglycemic and hypolipidimic effects in alloxan induced diabetic rats. Progressive Agriculture 29 (2): 139-146, 2018

The rat strains Wistar, Wistar–Kyoto, Sprague Dawley, Long Evans, LT (low CNS excitability threshold), SHR, BD-IX (“Biocollection of the Pavlov Institute of Physiology”) were comparatively screened for the indicators of hormonal and antioxidant status as well as behavior. In male rats, the following characteristics were evaluated: behavioral (locomotor activity, anxiety level, depressive-like behavior in the Prosolt forced swim test), hormonal (corticosterone, dehydroepiandrosterone–DHEA, thyroid-stimulating hormone–TSH, thyroxine and testosterone levels) and blood antioxidative activity. Considering our data on physiological phenotyping the above rat strains, physiological maps were created for each strain and a specific descriptive biocollection format was elaborated to represent relevant information as a publicly available online resource ( http://hst5.infran.ru/biocollection/ ) which can be helpful in choosing an experimental object and instrumental in analyzing data obtained on certain rat strains.

Rat pup ultrasonic vocalizations (USV) are usually studied in outbred rats belonging to either Long-Evans, Sprague-Dawley, or Wistar stocks, but these were not compared so far. We therefore performed a stock comparison and analyzed USV of male pups (postnatal day 11) belonging to these three stocks. Pups of all three stocks showed substantial isolation-induced USV, but differed in various call features, like call numbers, peak frequency, and frequency modulation. Also, three different call types were identified by means of a quantitative approach based on peak frequency and frequency modulation, and it was found that their proportions differed between stocks. These results are discussed with respect to functional aspects of pup USV.

Several human imaging studies have suggested that anterior cingulate cortex (ACC) is highly active when participants receive competing inputs, and that these signals may be important for influencing the downstream planning of actions. Despite increasing evidence from several neuroimaging studies, no study has examined ACC activity at the level of the single neuron in rodents performing similar tasks. To fill this gap, we recorded from single neurons in ACC while rats performed a stop-change task. We found higher firing on trials with competing inputs (STOP trials), and that firing rates were positively correlated with accuracy and movement speed, suggesting that when ACC was engaged, rats tended to slow down and perform better. Finally, firing was the strongest when STOP trials were preceded by GO trials and was reduced when rats adapted their behavior on trials subsequent to a STOP trial. These data provide the first evidence that activity of single neurons in ACC is elevated when 2 responses are in competition with each other when there is a need to change the course of action to obtain reward.

The representation of others in space Different sets of neurons encode the spatial position and orientation of an organism. However, social animals need to know the position of other individuals for social interactions, observational learning, and group navigation. Surprisingly, very little is known about how the position of other animals is represented in the brain. Danjo et al. and Omer et al. now report the discovery of a subgroup of neurons in hippocampal area CA1 that encodes the presence of conspecifics in rat and bat brains, respectively. Science , this issue p. 213 , p. 218

Dopaminergic reward prediction errors in monkeys reflect inferential reward predictions that well-trained animals can make when associative rules change. Here, in a new analysis of previously described data, we test whether dopaminergic error signals in rats are influenced by inferential predictions and whether such effects depend on the orbitofrontal cortex (OFC). Dopamine neurons were recorded from controls or rats with ipsilateral OFC lesions during performance of a choice task in which odor cues signaled the availability of sucrose reward in 2 wells. To induce prediction errors, we manipulated either the timing or number of rewards delivered in each well across blocks of trials. Of importance, a change in reward at 1 well predicted a change in reward at the other on later trials. We compared behavior and neural activity on trials when such inference was possible versus trials involving the same reward change when inference was not possible. Rats responded faster when they could infer an increase in reward compared to when the same reward was coming but they could not infer a change. This inferential prediction was reflected in the firing of dopamine neurons in controls, which changed less to unexpected delivery (or omission) of reward and more to the new high-value cue on inference versus noninference trials. These effects were absent in dopamine neurons recorded in rats with ipsilateral OFC lesions. Thus, dopaminergic error signals recorded in rats are influenced by both experiential and inferential reward predictions, and the effects of inferential predictions depend on OFC. (PsycINFO Database Record

The mechanisms underlying the maturation of learning and memory abilities are poorly understood. Here we show that episodic learning produces unique biological changes in the hippocampus of infant rats and mice compared to juveniles and adults. These changes include persistent neuronal activation, BDNF-dependent increase in the excitatory synapse markers synaptophysin and PSD-95, and significant maturation of AMPA receptor synaptic responses. Inhibition of PSD-95 induction following learning impairs both AMPA receptor response maturation and infantile memory, indicating that the synapse formation/maturation is necessary for creating infantile memories. Conversely, capturing the learning-induced changes by presenting a subsequent learning experience or by chemogenetic activation of the neural ensembles tagged by learning matures memory functional competence. This memory competence is selective for the type of experience encountered, as it transfers within similar hippocampus-dependent learning domains but not to other hippocampus-dependent types of learning. Thus, experiences in early life produce selective maturation of memory abilities., The mechanisms underlying the maturation of learning and memory abilities are poorly understood. Here, authors show that episodic learning produces persistent neuronal activation, BDNF-dependent increase in excitatory synapse markers (synaptophysin and PSD-95), and significant maturation of AMPA receptor synaptic responses in the hippocampus of infant rats and mice compared to juveniles and adults.

The head direction (HD) signal is thought to originate in the reciprocal connections between the dorsal tegmental nuclei (DTN) and the lateral mammillary nuclei (LMN) and lesions to these structures disrupt the HD signal in downstream structures. Lesions to the DTN also disrupt performance on spatial tasks where directional heading is thought to be important. In Experiment 1, rats with bilateral electrolytic lesions of the LMN and sham controls were trained on 2 tasks previously shown to be sensitive to DTN damage. Rats were first trained on either a direction or rotation problem in a water T maze. LMN-lesioned rats were impaired relative to sham controls, on both the first block of 8 trials and on the total number of trials taken to reach criterion. In the food-foraging task, rats were trained to leave a home cage at the periphery of a circular table, find food in a food cup at the center of the table, and return to the home cage. Again, LMN-lesioned rats were impaired relative to sham rats, making more errors on the return component of the foraging trip. In Experiment 2, rats with electrolytic LMN lesions were also impaired on a dry land version of the direction and rotation problems and had difficulty discriminating between reinforced and nonreinforced locations on a 12-arm maze. These results build on previous behavioral and cell-recording studies and demonstrate the importance of the direction system to spatial learning. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

In this article we addressed the question whether rats can use distal landmarks as directional cues that are used in combination with other proximal landmark configurations. The animals were trained with an A, B, C, and D landmark configuration in the Morris pool, where B and C are the near (to platform) landmarks and A and D the far ones. We also added another more distal "directional" cue Z (a white strip attached to the black curtain surrounding the pool). Experiment 1a shows a robust detrimental effect on the time spent by the rats swimming in the platform quadrant when the location of all landmarks was "Inverted" (rotated by 180 degrees) with respect to Z. A similar detrimental effect was found when, after the inversion manipulation, the locations of the near and far landmarks were "Flipped" (B swapped with C and A with D). Rats in both Inverted and Flipped tests spent more time in the Z quadrant compared to the platform quadrant (BC). Experiment 1b provided evidence distinguishing between alternative explanations of how the directional cue Z acts in combination with the other landmarks. The results from both experiments show that Z operates differently to the standard landmarks. It can function as a beacon in its own right. It can also combine with the other landmarks to produce a high level of search performance, in a way that we hypothesize to be distinct from that described by the configural analysis often applied to multiple landmarks. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

International audience; Under anesthesia, systemic variables and CBF are modified. How does this alter the connectivity measures obtained with rs-fMRI? To tackle this question, we explored the effect of four different anesthetics on Long Evans and Wistar rats with multimodal recordings of rs-fMRI, systemic variables and CBF. After multimodal signal processing, we show that the blood-oxygen-level-dependent (BOLD) variations and functional connectivity (FC) evaluated at low frequencies (0.031-0.25 Hz) do not depend on systemic variables and are preserved across a large interval of baseline CBF values. Based on these findings, we found that most brain areas remain functionally active under any anesthetics, i.e. connected to at least one other brain area, as shown by the connectivity graphs. In addition, we quantified the influence of nodes by a measure of functional connectivity strength to show the specific areas targeted by anesthetics and compare correlation values of edges at different levels. These measures enable us to highlight the specific network alterations induced by anesthetics. Altogether, this suggests that changes in connectivity could be evaluated under anesthesia, routinely used in the control of neurological injury.

The staple line leakage is a dangerous complication of sleeve gastrectomy. Various strategies have been tried to reduce the leakage risk. The amniotic membrane (AmM) is the inner layer of the placental membranes and has anti-inflammatory, anti-fibrosis, and anti-scarring effects, and it also has lower immune characteristics which are another essential characteristic of AmM concerning its utility for grafting. In this study, we aimed to investigate the impact of AmM on the staple line healing process of sleeve gastrectomy model in rats. We used twenty-eight Long-Evans rats in this study. Sleeve gastrectomy was performed with tristapler. Fourteen rats served as controls, AmM was applied staple line of the other fourteen. Fourteen animals were sacrificed (seven from the AmM applied group and the other seven from the control group) on the third postoperative day. And, the other fourteen animals were sacrificed (seven from the AmM applied group and seven from the control group) on the seventh postoperative day. The tissue around the staple line was evaluated microscopically and macroscopically, bursting pressures and hydroxyproline levels were also measured. The bursting pressure and hydroxyproline measurements of the AmM applied group was significantly higher on the seventh postoperative day (p = 0.015, p = 0.012) Fibroblast activity and neoangiogenesis of the AmM applied group was also significantly higher on the seventh postoperative day (p = 0.004, p = 0.002). This study showed that covering of staple line of sleeve gastrectomy model in rats significantly provided higher bursting pressures and increased hydroxyproline levels, fibroblast activity, and neoangiogenesis which may potentially lead a better staple line healing. We think further investigations are needed on this issue.

The dopamine projection from ventral tegmental area (VTA) to nucleus accumbens (NAc) is critical for motivation to work for rewards and reward-driven learning. How dopamine supports both functions is unclear. Dopaminecell spiking can encode prediction errors, which arevital learning signals in computational theories of adaptive behaviour. By contrast, dopamine release ramps up as animals approach rewards, mirroring reward expectation. This mismatch might reflect differences in behavioural tasks, slower changes in dopamine cell spiking or spike-independent modulation of dopamine release. Here we compare spiking of identified VTA dopamine cells with NAc dopamine release in the same decision-making task. Cues thatindicatean upcoming reward increased both spiking and release. However, NAc core dopamine release also covaried with dynamically evolving reward expectations, without corresponding changes in VTA dopamine cell spiking. Our results suggest a fundamental difference in how dopamine release is regulated to achieve distinct functions: broadcast burst signals promote learning, whereas local control drives motivation.