Cylinder Task Research Articles

Are lizards capable of inhibitory control? Performance on a semi-transparent version of the cylinder task in five species of Australian skinks

Inhibitory control, the inhibition of prepotent actions, is essential for higher-order cognitive processes such as planning, reasoning, and self-regulation. Individuals and species differ in inhibitory control. Identifying what influences inhibitory control ability within and between species is key to understanding how it evolved. We compared performance in the cylinder task across five lizard species: tree skinks (Egernia striolata), gidgee skinks (Egernia stokesii), eastern blue-tongue skinks (Tiliqua s. scincoides), sleepy lizards (Tiliqua r. asper), and eastern water skinks (Eulamprus quoyii). In our task, animals had to inhibit the prepotent motor response of directly approaching a reward placed within a semi-transparent mesh cylinder and instead reach in through the side openings. Additionally, in three lizard species, we compared performance in the cylinder task to reversal learning to determine the task specificity of inhibitory ability. Within species, neither sex, origin, body condition, neophobia, nor pre-experience with other cognitive tests affected individual performance. Species differed in motor response inhibition: Blue-tongue skinks made fewer contacts with the semi-transparent cylinder wall than all other species. Blue-tongue skinks also had lower body condition than the other species which suggest motivation as the underlying cause for species differences in task performance. Moreover, we found no correlation between inhibitory ability across different experiments. This is the first study comparing cylinder task performance among lizard species. Given that inhibitory control is probably widespread in lizards, motor response inhibition as exercised in the cylinder task appears to have a long evolutionary history and is likely fundamental to survival and fitness.SignificanceThe study of lizard cognition is receiving increasing attention. Lizards are a diverse group with a wide range of ecological attributes and represent a model system through which we can test a wide range of hypotheses relating to cognitive evolution. Furthermore, considering their evolutionary history, studying non-avian reptile cognition can help understand the evolution of different cognitive abilities including inhibitory control. Here, we provide a comparison of inhibitory control ability in five lizard species. Consequently, we are able to, firstly, validate a method (the cylinder task) initially developed for the use in mammals and birds, for use in lizards, and secondly, collect valuable data on inhibitory control in a poorly studied group with respect to cognitive ability. Our study suggests non-cognitive factors as a major influence on cylinder task performance, which is in agreement with previous studies of other vertebrates.

Measures of inhibitory control correlate between different tasks but do not predict problem-solving success in a fish, Poecilia reticulata

Once considered a human characteristic, the presence of correlations between individuals' performance in cognitive tasks has now been reported in a range of vertebrates. In humans, an important source of cognitive variability is inhibitory control: some individuals are consistently more efficient in inhibitory tasks and this affects individual differences in other cognitive tasks, including measures of general intelligence. We looked for these two types of individual differences in a teleost fish, the guppy Poecilia reticulata. First, we observed guppies in two inhibitory control tasks. In the tube task, guppies had to inhibit the tendency to attack live prey sealed into a transparent tube. In the cylinder task, guppies had to inhibit the tendency to swim directly toward a food item placed inside a transparent cylinder and rather detour and enter the cylinder from the open sides. Individual rank performance was maintained between the two inhibitory tasks, suggesting individual differences in inhibitory control across tasks in this species. Then, we tested the same set of guppies in a problem-solving task, whereby they had to learn to dislodge an object that prevented the access to a food reward. Neither the tube task nor the cylinder task score predicted guppies' problem-solving performance. Our study demonstrates that fish exhibit consistent individual differences in inhibitory control, as expected if this trait has a common evolutionary origin in vertebrates. Yet, in fish, these individual differences appear not to be related to other cognitive processes such as those required for problem solving.

HDAC2 (Histone deacetylase 2): A critical factor in environmental enrichment-mediated stroke recovery.

Environmental enrichment (EE) is a generally accepted strategy to promote stroke recovery and its beneficial effect is positively correlated with neuroplasticity. However, the mechanisms underlying it remain elusive. Histone deacetylase 2 (HDAC2), a negative regulator of neuroplasticity, is up-regulated after stroke. Thus, we hypothesized that HDAC2 may participate in EE-mediated stroke recovery. In this study, focal stroke was induced by photothrombosis in male mice exposing to EE or standard housing (SH) conditions. Recombinant virus vectors, including Ad-HDAC2-Flag, AAV-CAG-EGFP-Cre, LV-shHDAC2, or their controls were microinjected into the motor cortex at 3days before stroke. Grid-walking and cylinder tasks were conducted to assess motor function. Western blot and immunostaining were used to uncover the mechanisms underlying EE-mediated stroke recovery. We found that EE exposure reversed stroke-induced HDAC2 up-regulation, implicating HDAC2 in EE-mediated functional recovery. Importantly, EE-dependent stroke recovery was counteracted by over-expressing HDAC2, and HDAC2 knockdown promoted functional recovery from stroke to the similar extent as EE exposure. Moreover, the knockdown of HDAC2 epigenetically enhanced expressions of neurotrophins and neuroplasticity-related proteins, with similar effects as EE, and consequently, whole brain and corticospinal tract (CST) rewiring. Together, our findings indicate that HDAC2 is critical for EE-dependent functional restoration. Precisely targeting HDAC2 may mimic EE and serve as a novel therapeutic strategy for stroke recovery.

The effects of mouse strain and age on a model of unilateral cervical contusion spinal cord injury.

There are approximately 1.2 million people currently living with spinal cord injury (SCI), with a majority of cases at the cervical level and half involving incomplete injuries. Yet, as most preclinical research has been focused on bilateral thoracic models, there remains a disconnect between bench and bedside that limits translational success. Here, we profile a clinically relevant model of unilateral cervical contusion injury in the mouse (30kD with 0, 2, 5, or 10 second dwell time). We demonstrate sustained behavioral deficits in performance on grip strength, cylinder reaching, horizontal ladderbeam and CatWalk automated gait analysis tasks. Beyond highlighting reliable parameters for injury assessment, we also explored the effect of mouse strain and age on injury outcome, including evaluation of constitutively immunodeficient mice relevant for neurotransplantation and cellular therapy testing. Comparison of C57Bl/6 and immunodeficient Rag2gamma(c)-/- as well as Agouti SCIDxRag2Gamma(c)-/- hybrid mouse strains revealed fine differences in post-injury ipsilateral grip strength as well as total number of rearings on the cylinder task. Differences in post-SCI contralateral forepaw duty cycle and regularity index as measured by CatWalk gait analysis between the two immunodeficient strains were also observed. Further, assessment of young (3–4 months old) and aging (16–17 months old) Rag2gamma(c)-/- mice identified age-related pre-injury differences in strength and rearing that were largely masked following cervical contusion injury; observations that may help interpret previous results in aged rodents as well as human clinical trials. Collectively, the work provides useful insight for experimental design and analysis of future pre-clinical studies in a translational unilateral cervical contusion injury model.

Thinking outside the box: problem-solving in free-living lizards

Despite evidence that organisms are more likely to exhibit their full range of cognitive abilities under conditions found in nature, studies evaluating cognition under such conditions remain rare, particularly in vertebrate species. Here, we conducted an experiment to evaluate problem-solving and motor self-regulation in free-living arboreal lizards, Anolis sagrei, under natural conditions. We presented lizards with a novel detour problem which challenged individuals to circumvent a transparent barrier in order to obtain a food reward. Individuals varied in their ability to solve the detour problem. Furthermore, those that solved the problem were able to improve their performance across trials by modifying the natural response of attempting to strike the reward through the transparent barrier, providing evidence of motor self-regulation. Solving the problem required individuals to modify their typical foraging behavior, as approaching the prey in a single burst of movement that culminated with an attack was an unsuccessful strategy. Contrary to expectations, our findings provide evidence of motor self-regulation in a visually oriented, sit-and-wait predator under natural conditions, suggesting motor self-regulation is not limited by foraging strategy. Our results also underscore the need to evaluate the cognitive abilities of free-living organisms in the wild, particularly for taxa that perform poorly under laboratory conditions. Studies of animal cognition have a long history in animal behavior, which, in vertebrate species, has been dominated by experiments conducted under controlled laboratory conditions. Here, we showed that experiments can be taken “outside the box,” from the laboratory into natural conditions, and by doing so overcome some of the obstacles that have hindered our ability to study cognition in species unlikely to remain motivated when removed from the wild. We implemented a modified version of the cylinder task, which provided the stimuli needed for a visually oriented, sit-and-wait foraging lizard to participate in the experiments. Individuals of Anolis sagrei learned to solve the task by modifying what was previously described as a stereotyped prey capture behavior. In addition, individuals decreased the number of times they attempted to strike the prey through the transparent barrier. These findings provide further evidence of behavioral flexibility in anoles and new evidence of motor self-regulation. The latter demonstrates the need to extend our current understanding of potential forces favoring the evolution of cognition beyond those that have been proposed in birds and mammals. More generally, our findings demonstrate the importance of using experimental paradigms that are rooted in an understanding of the natural history of the species of interest.

Inhibitory control – Important trait for explosive detection performance in police dogs?

Working dogs are used for a range of important operational tasks. Identifying potentially successful working dogs as early as possible is important as rejection rates are high and training is costly. Earlier research has mainly concentrated on personality traits such as boldness, and there is only little knowledge on the possible association between cognitive traits and the actual working dog performance. This study investigated whether motor inhibition, persistence, problem-solving strategies, and spatial problem-solving are associated with explosive detection success in specially trained police dogs. Dogs (N = 24) were tested with a cognitive test battery, and subsequently they participated in an explosive detection test. The explosive searching situation and the location of the test was such that it would reflect as much as possible a real-life situation. Canine handlers also filled in a questionnaire regarding their dog’s working behaviour. We found that those dogs that were more successful in explosive detection task had better motor inhibition in a cylinder task compared to dogs with lower success in an explosive search task. Furthermore, we found that dogs that made more errors in the cylinder task were generally more likely to give up searching sooner, as reported by their handlers, and also abandon sooner the problem-solving task in behavioural test. This study suggests that inhibitory control, specifically motor inhibition, may be an important aspect to consider when selecting suitable dogs for explosive detection tasks. Cylinder task is an easy and quick way to assess inhibitory control, although a larger dataset is needed to verify its association with working performance.

Uninhibited chickens: ranging behaviour impacts motor self-regulation in free-range broiler chickens (Gallus gallus domesticus).

Inhibiting impulsive, less flexible behaviours is of utmost importance for individual adaptation in an ever-changing environment. However, problem-solving tasks may be greatly impacted by individual differences in behaviour, since animals with distinct behavioural types perceive and interact with their environment differently, resulting in variable responses to the same stimuli. Here, we tested whether and how differences in ranging behaviour of free-range chickens affect motor self-regulation performance during a cylinder task. For this task, subjects must refrain from trying to reach a food reward through the walls of a transparent cylinder and detour to its open sides, as a sign of inhibition. Free-range chickens exhibited an overall low performance in the motor self-regulation task (31.33 ± 13.55% of correct responses), however, high rangers showed significantly poorer performance than the low rangers (23.75 ± 9.16% versus 40 ± 12.90%, respectively). These results give further support to the impacts of individual behavioural differences on cognitive performances. This is the first demonstration to our knowledge of a relationship between exploratory tendencies and motor self-regulation for an avian species.

Response learning confounds assays of inhibitory control on detour tasks

The ability to inhibit prepotent actions towards rewards that are made inaccessible by transparent barriers has been considered to reflect capacities for inhibitory control (IC). Typically, subjects initially reach directly, and incorrectly, for the reward. With experience, subjects may inhibit this action and instead detour around barriers to access the reward. However, assays of IC are often measured across multiple trials, with the location of the reward remaining constant. Consequently, other cognitive processes, such as response learning (acquisition of a motor routine), may confound accurate assays of IC. We measured baseline IC capacities in pheasant chicks, Phasianus colchicus, using a transparent cylinder task. Birds were then divided into two training treatments, where they learned to access a reward placed behind a transparent barrier, but experienced differential reinforcement of a particular motor response. In the stationary-barrier treatment, the location of the barrier remained constant across trials. We, therefore, reinforced a fixed motor response, such as always go left, which birds could learn to aid their performance. Conversely, we alternated the location of the barrier across trials for birds in the moving-barrier treatment and hence provided less reinforcement of their response learning. All birds then experienced a second presentation of the transparent cylinder task to assess whether differences in the training treatments influenced their subsequent capacities for IC. Birds in the stationary-barrier treatment showed a greater improvement in their subsequent IC performance after training compared to birds in the moving-barrier treatment. We, therefore, suggest that response learning aids IC performance on detour tasks. Consequently, non-target cognitive processes associated with different neural substrates appear to underlie performances on detour tasks, which may confound accurate assays of IC. Our findings question the construct validity of a commonly used paradigm that is widely considered to assess capacities for IC in humans and other animals.

The Delta-Subunit Selective GABA A Receptor Modulator, DS2, Improves Stroke Recovery via an Anti-inflammatory Mechanism.

Inflammatory processes are known to contribute to tissue damage in the central nervous system (CNS) across a broad range of neurological conditions, including stroke. Gamma amino butyric acid (GABA), the main inhibitory neurotransmitter in the CNS, has been implicated in modulating peripheral immune responses by acting on GABAA receptors on antigen-presenting cells and lymphocytes. Here, we investigated the effects and mechanism of action of the delta-selective compound, DS2, to improve stroke recovery and modulate inflammation. We report a decrease in nuclear factor (NF)-κB activation in innate immune cells over a concentration range in vitro. Following a photochemically induced motor cortex stroke, treatment with DS2 at 0.1 mg/kg from 1 h post-stroke significantly decreased circulating tumor necrosis factor (TNF)-α, interleukin (IL)-17, and IL-6 levels, reduced infarct size and improved motor function in mice. Free brain concentrations of DS2 were found to be lower than needed for robust modulation of central GABAA receptors and were not affected by the presence and absence of elacridar, an inhibitor of both P-glycoprotein and breast cancer resistance protein (BCRP). Finally, as DS2 appears to dampen peripheral immune activation and only shows limited brain exposure, we assessed the role of DS2 to promote functional recovery after stroke when administered from 3-days after the stroke. Treatment with DS2 from 3-days post-stroke improved motor function on the grid-walking, but not on the cylinder task. These data highlight the need to further develop subunit-selective compounds to better understand change in GABA receptor signaling pathways both centrally and peripherally. Importantly, we show that GABA compounds such as DS2 that only shows limited brain exposure can still afford significant protection and promote functional recovery most likely via modulation of peripheral immune cells and could be given as an adjunct treatment.

Guppies show rapid and lasting inhibition of foraging behaviour

To cope with the variable environment, animals are continuously required to learn novel behaviours or, in certain cases, to inhibit automatic and previously learned behaviours. Traditionally, inhibition has been regarded as cognitively demanding and studied mostly in primates, other mammals and birds, using laboratory tasks, such as the cylinder task. Recent studies have also revealed that fish show high levels of inhibition in the cylinder task. However, conclusions on such results are undermined by evidence that the cylinder task may be inappropriate to compare such phylogenetically distant species. Here, we studied whether a fish, the guppy, Poecilia reticulata, could learn to inhibit behaviour using a different paradigm, which exploited spontaneous foraging behaviour and overcame some drawbacks that characterised the cylinder task. We exposed guppies to live brine shrimp nauplii, Artemia salina, enclosed within a transparent tube. Initially, the guppies attempted to attack the prey but over time showed a rapid decrease of the attacks. Control tests seemed to exclude the possibility that this behavioural trend was due to response to novelty or habituation, and suggested that the guppies were learning to inhibit the foraging behaviour. Memory tests indicated that guppies retained the inhibition of foraging behaviour for at least 24 h. Our study seems to indicate that teleost fish display rapid and durable inhibition of spontaneous foraging behaviour; this may be related to previous evidence, from the cylinder task, supporting efficient behavioural inhibition in this taxon.

The effect of experience and olfactory cue in an inhibitory control task in guppies, Poecilia reticulata

Behavioural responses to the environment often require the suppression of strong internal predispositions or the overriding of external lures, tasks performed by a cognitive function called inhibitory control. Inhibitory control of nonhuman animals is generally measured with the cylinder task: subjects are presented with food inside a transparent cylinder and must inhibit their tendency to reach the food directly and instead detour round the cylinder to solve the task. However, several studies have raised concerns about the validity of this test to compare different species. Recently, a tiny teleost fish, the guppy, Poecilia reticulata, was tested with the cylinder task and scored higher than many mammals and birds. Before considering that guppies display unpredictably high inhibitory control, it is important to exclude that they were advantaged by some noncognitive factors. In particular, guppies could enjoy three advantages: experience with transparent surfaces (i.e. the walls of maintenance aquaria), experience with detouring round see-through obstacles (vegetation in the maintenance aquaria) and the spread of food odour in the water from the sides of the cylinder. We tested whether these factors affect guppies' performance in the cylinder task by manipulating both their experience with transparent surfaces before the task and the diffusion of food odour cues from the cylinder. Guppies raised in transparent aquaria or with transparent panels placed inside the tank did not show advantages over guppies with no experience with transparent surfaces. Furthermore, the guppies’ performance was not reduced when the cylinder was pierced in the middle, so that both visual and olfactory cues lured them in the same direction. These results seem to exclude methodological explanations for the high inhibitory control score of guppies, and they indicate that even teleost fish can display efficient inhibitory control.

Dissociating nNOS (Neuronal NO Synthase)-CAPON (Carboxy-Terminal Postsynaptic Density-95/Discs Large/Zona Occludens-1 Ligand of nNOS) Interaction Promotes Functional Recovery After Stroke via Enhanced Structural Neuroplasticity.

Background and Purpose- Stroke is a major public health concern worldwide. Although clinical treatments have improved in the acute period after stroke, long-term therapeutics remain limited to physical rehabilitation in the delayed phase. This study is aimed to determine whether nNOS (neuronal NO synthase)-CAPON (carboxy-terminal postsynaptic density-95/discs large/zona occludens-1 ligand of nNOS) interaction may serve as a new therapeutic target in the delayed phase for stroke recovery. Methods- Photothrombotic stroke and transient middle cerebral artery occlusion were induced in mice. Adeno-associated virus (AAV)-cytomegalovirus (CMV)-CAPON-125C-GFP (green fluorescent protein)-3Flag and the other 2 drugs (Tat-CAPON-12C and ZLc-002) were microinjected into the peri-infarct cortex immediately and 4 to 10 days after photothrombotic stroke, respectively. ZLc-002 was also systemically injected 4 to 10 days after transient middle cerebral artery occlusion. Grid-walking task and cylinder task were conducted to assess motor function. Western blotting, immunohistochemistry, Golgi staining, and electrophysiology recordings were performed to uncover the mechanisms. Results- Stroke increased nNOS-CAPON association in the peri-infarct cortex in the delayed period. Inhibiting the ischemia-induced nNOS-CAPON association substantially decreased the number of foot faults in the grid-walking task and forelimb asymmetry in the cylinder task, suggesting the promotion of functional recovery from stroke. Moreover, dissociating nNOS-CAPON significantly facilitated dendritic remodeling and synaptic transmission, indicated by increased dendritic spine density, dendritic branching, and length and miniature excitatory postsynaptic current frequency but did not affect stroke-elicited neuronal loss, infarct size, or cerebral edema, suggesting that nNOS-CAPON interaction may function via regulating structural neuroplasticity, rather than neuroprotection. Furthermore, ZLc-002 reversed the transient middle cerebral artery occlusion-induced impairment of motor function. Conclusions- Our results reveal that nNOS-CAPON coupling can serve as a novel pharmacological target for functional restoration after stroke.

Response-Inhibition During Problem Solving in Sheep (Ovis Aries)

Response inhibition is a behavioural skill that is important for flexible behaviour and appropriate decision making. It requires the suppression of a prepotent, but inappropriate action, in order to achieve a more advantageous outcome. Response inhibition has been tested in many animal species using the cylinder task. This task requires the self-driven inhibition of an impulse to obtain a visible food reward via a detour, rather than a direct but blocked route. We have shown previously using the stop-signal task that sheep can successfully interrupt an already-started response, if a reward is going to be restricted. However, it is not known if sheep can show self-driven response inhibition in a task that provides a reward independent of performance. Here we tested two groups of sheep on the cylinder task (11 Lleyn sheep: aged 8 months; 8 Welsh mountain sheep aged ~8 years old). Sheep were trained using an opaque cylinder and all sheep successfully learned the task. When response inhibition was tested using the transparent cylinder, all sheep performed significantly better than chance, but the older sheep showed a reduced number of correct responses compared to the young sheep (72.5±5.0% and 86.4±4.3% respectively). The results show that sheep have a mechanism for self-regulating their actions in order to retrieve food faster.

Response-inhibition during problem solving in sheep

Author(s): Knolle, Franziska; Goncalves, Rita P.; Davies, Emma L.; Duff, Amy R.; Morton, A. Jennifer | Abstract: Response inhibition is a behavioural skill that is important for flexible behaviour and appropriate decision making. It requires the suppression of a prepotent, but inappropriate action, in order to achieve a more advantageous outcome. Response inhibition has been tested in many animal species using the cylinder task. This task requires the self-driven inhibition of an impulse to obtain a visible food reward via a detour, rather than a direct but blocked route. We have shown previously using the stop-signal task that sheep can successfully interrupt an already-started response, if a reward is going to be restricted. However, it is not known if sheep can show self-driven response inhibition in a task that provides a reward independent of performance. Here we tested two groups of sheep on the cylinder task (11 Lleyn sheep: aged 8 months; 8 Welsh mountain sheep aged ~8 years old). Sheep were trained using an opaque cylinder and all sheep successfully learned the task. When response inhibition was tested using the transparent cylinder, all sheep performed significantly better than chance, but the older sheep showed a reduced number of correct responses compared to the young sheep (72.5±5.0% and 86.4±4.3% respectively). The results show that sheep have a mechanism for self-regulating their actions in order to retrieve food faster.n

Cats Parallel Great Apes and Corvids in Motor Self-Regulation - Not Brain but Material Size Matters.

The inhibition of unproductive motor movements is regarded as a fundamental cognitive mechanism. Recently it has been shown that species with large absolute brain size or high numbers of pallial neurons, like great apes and corvids, show the highest performance on a task purportedly measuring this mechanism: the cylinder task. In this task the subject must detour a perpendicularly oriented transparent cylinder to reach a reward through a side opening, instead of directly reaching for it and bumping into the front, which is regarded as an inhibitory failure. Here we test domestic cats, for the first time, and show that they can reach the same levels as great apes and corvids on this task, despite having much smaller brains. We tested subjects with apparatuses that varied in size (cylinder length and diameter) and material (glass or plastic), and found that subjects performed best on the large cylinders. As numbers of successes decreased significantly when the cylinders were smaller, we conducted additionally two experiments to discern which properties (length of the transparent surface, goal distance from the surface, size of the side opening) affects performance. We conclude that sensorimotor requirements, which differ between species, may have large impact on the results in such seemingly simple and apparently comparable tests. However, we also conclude that cats have comparably high levels of motor self-regulation, despite the differences between tests.

The degree of altriciality and performance in a cognitive task show correlated evolution

Previous comparative research on the evolution of cognition has tested what we call the “altricial intelligence hypothesis”. This posits that a relationship between evolutionary changes in the altricial period length and cognition exists across animal species. However, the evidence available thus far either comes from indirect measurements of cognition or has not been conclusive. We performed a phylogenetic analysis of published data from various sources on 31 homeothermic species to test for an evolutionary association between the degree of altriciality and a direct measure of self-control. For each species, the degree of altriciality was determined based on the residual altricial period (i.e., the time from birth to fledging in birds and to weaning in mammals) on lifespan. The percentage of success in the cylinder task was the measure of self-control. Our results showed that the degree of altriciality covaried positively with the measure of self-control. Based on the results of this study, we sustain that evolutionary changes in the length of the altricial period are associated with evolutionary changes in the cognitive system used by homeotherms to perform the cylinder task.

Individual performance across motoric self-regulation tasks are not correlated for pet dogs.

Inhibitory control, the ability to restrain a prepotent but ineffective response in a given context, is thought to be indicative of a species' cognitive abilities. This ability ranges from "basic" motoric self-regulation to more complex abilities such as self-control. During the current study, we investigated the motoric self-regulatory abilities of 30 pet dogs using four well-established cognitive tasks - the A-not-B Bucket task, the Cylinder task, the Detour task, and the A-not-B Barrier task - administered in a consistent context. One main goal of the study was to determine whether the individual-level performance would correlate across tasks, supporting that these tasks measure similar components of motoric self-regulation. Dogs in our study were quite successful during tasks requiring them to detour around transparent barriers (i.e., the Cylinder and Detour tasks), but were less successful with tasks requiring the production of a new response (i.e., A-not-B Bucket and A-not-B Barrier tasks). However, individual dog performance did not correlate across tasks, suggesting these well-established tasks likely measure different inhibitory control abilities, or are strongly influenced by differential task demands. Our results also suggest other aspects such as perseveration or properties of the apparatus may need to be carefully examined in order to better understand canine motoric self-regulation or inhibitory control more generally.

Motor self-regulation in goats (Capra aegagrus hircus) in a detour-reaching task.

Motor self-regulation is the ability to inhibit a prepotent response to a salient cue in favour of a more appropriate response. Motor self-regulation is an important component of the processes that interact to generate effective inhibitory control of behaviour, and is theorized to be a prerequisite of complex cognitive abilities in humans and other animals. In a large comparative study using the cylinder task, motor self-regulation was studied in 36 different species, mostly birds and primates. To broaden the range of species to comprehensively evaluate this phenomenon, motor self-regulation was studied in the domestic goat, which is a social ungulate species and moderate food specialist. Using the cylinder task, goats were first trained to perform a detour-reaching response to retrieve a reward from an opaque cylinder. Subsequently, an otherwise identical transparent cylinder was substituted for the opaque cylinder over 10 test trials. The goats’ ability to resist approaching the visible reward directly by touching the cylinder and to retain the trained detour-reaching response was measured. The results indicated that goats showed motor self-regulation at a level comparable to or better than that of many of the bird and mammal species tested to date. However, the individual reaction patterns revealed large intra- and inter-individual variability regarding motor self-regulation. An improvement across trials was observed only in latency to make contact with the reward; no improvement in the proportion of accurate trials was observed. A short, distinct pointing gesture by the experimenter during baiting did not have any impact on the side of the cylinder to which the goats detoured. In half of goats, individual side biases were observed when detouring to the side of the cylinder, but there was no bias at the population level for either the left or right side. The results underline the need for a detailed examination of individual performance and additional measures to achieve a complete understanding of animal performance in motor self-regulation tasks.

Neuroprotective Effects of Guanosine Administration on In Vivo Cortical Focal Ischemia in Female and Male Wistar Rats.

Guanosine (GUO) has neuroprotective effects in experimental models of brain diseases involving glutamatergic excitotoxicity in male animals; however, its effects in female animals are poorly understood. Thus, we investigated the influence of gender and GUO treatment in adult male and female Wistar rats submitted to focal permanent cerebral ischemia in the motor cortex brain. Female rats were subdivided into non-estrogenic and estrogenic phase groups by estrous cycle verification. Immediately after surgeries, the ischemic animals were treated with GUO or a saline solution. Open field and elevated plus maze tasks were conducted with ischemic and naïve animals. Cylinder task, immunohistochemistry and infarct volume analyses were conducted only with ischemic animals. Female GUO groups achieved a full recovery of the forelimb symmetry at 28-35days after the insult, while male GUO groups only partially recovered at 42days, in the final evaluation. The ischemic insult affected long-term memory habituation to novelty only in female groups. Anxiety-like behavior, astrocyte morphology and infarct volume were not affected. Regardless the estrous cycle, the ischemic injury affected differently female and male animals. Thus, this study points that GUO is a potential neuroprotective compound in experimental stroke and that more studies, considering the estrous cycle, with both genders are recommended in future investigation concerning brain diseases.

Neophobia does not account for motoric self-regulation performance as measured during the detour-reaching cylinder task.

The ability to restrain a prepotent response in favor of a more adaptive behavior, or to exert inhibitory control, has been used as a measure of a species' cognitive abilities. Inhibitory control defines a spectrum of behaviors varying in complexity, ranging from self-control to motoric self-regulation. Several factors underlying inhibitory control have been identified, however, the influence of neophobia (i.e., aversion to novelty) on inhibitory control has not received much attention. Neophobia is known to affect complex cognitive abilities, but whether neophobia also influences more basic cognitive abilities, such as motoric self-regulation, has received less attention. Further, it remains unclear whether an individual's response to novelty is consistent across different paradigms purported to assess neophobia. We tested two North American corvid species, black-billed magpies (Pica hudsonia) and California scrub jays (Aphelocoma californica) using two well-established neophobia paradigms to assess response stability between contexts. We then evaluated neophobia scores against the number of trials needed to learn a motoric self-regulation task, as well as subsequent task performance. Neophobia scores did not correlate across paradigms, nor did the responses during either paradigm account for motoric self-regulation performance.