Perirhinal cortex learns a predictive map of the task environment.

Goal-directed tasks involve acquiring an internal model, known as a predictive map, of relevant stimuli and associated outcomes to guide behavior. Here, we identified neural signatures of a predictive map of task behavior in perirhinal cortex (Prh). Mice learned to perform a tactile working memory task by classifying sequential whisker stimuli over multiple training stages. Chronic two-photon calcium imaging, population analysis, and computational modeling revealed that Prh encodes stimulus features as sensory prediction errors. Prh forms stable stimulus-outcome associations that can progressively be decoded earlier in the trial as training advances and that generalize as animals learn new contingencies. Stimulus-outcome associations are linked to prospective network activity encoding possible expected outcomes. This link is mediated by cholinergic signaling to guide task performance, demonstrated by acetylcholine imaging and systemic pharmacological perturbation. We propose that Prh combines error-driven and map-like properties to acquire a predictive map of learned task behavior.

Sustained behaviour: Encoding of cumulative experience in the anterior cingulate.

Time is a ubiquitous dimension of behaviour. A new study demonstrates that low-dimensional temporal drift in rodent anterior cingulate ensembles encodes cumulative experience. These data provide fresh insight into how neurons encode extended periods of time to guide high-level behaviours.

Engrams: From Behavior to Brain-Wide Networks.

Animals utilize a repertoire of behavioral responses during everyday experiences. During a potentially dangerous encounter, defensive actions such as "fight, flight, or freeze" are selected for survival. The successful use of behavior is determined by a series of real-time computations combining an animal's internal (i.e., body) and external (i.e., environment) state. Brain-wide neural pathways are engaged throughout this process to detect stimuli, integrate information, and command behavioral output. The hippocampus, in particular, plays a role in the encoding and storing of the episodic information surrounding these encounters as putative "engram" or experience-modified cellular ensembles. Recalling a negative experience then reactivates a dedicated engram ensemble and elicits a behavioral response. How hippocampus-based engrams modulate brain-wide states and an animal's internal/external milieu to influence behavior is an exciting area of investigation for contemporary neuroscience. In this chapter, we provide an overview of recent technological advancements that allow researchers to tag, manipulate, and visualize putative engram ensembles, with an overarching goal of casually connecting their brain-wide underpinnings to behavior. We then discuss how hippocampal fear engrams alter behavior in a manner that is contingent on an environment's physical features as well as how they influence brain-wide patterns of cellular activity. Overall, we propose here that studies on memory engrams offer an exciting avenue for contemporary neuroscience to casually link the activity of cells to cognition and behavior while also offering testable theoretical and experimental frameworks for how the brain organizes experience.

Development of a Novel Classification Approach for Cow Behavior Analysis Using Tracking Data and Unsupervised Machine Learning Techniques.

Global Positioning Systems (GPSs) can collect tracking data to remotely monitor livestock well-being and pasture use. Supervised machine learning requires behavioral observations of monitored animals to identify changes in behavior, which is labor-intensive. Our goal was to identify animal behaviors automatically without using human observations. We designed a novel framework using unsupervised learning techniques. The framework contains two steps. The first step segments cattle tracking data using state-of-the-art time series segmentation algorithms, and the second step groups segments into clusters and then labels the clusters. To evaluate the applicability of our proposed framework, we utilized GPS tracking data collected from five cows in a 1096 ha rangeland pasture. Cow movement pathways were grouped into six behavior clusters based on velocity (m/min) and distance from water. Again, using velocity, these six clusters were classified into walking, grazing, and resting behaviors. The mean velocity for predicted walking and grazing and resting behavior was 44, 13 and 2 min/min, respectively, which is similar to other research. Predicted diurnal behavior patterns showed two primary grazing bouts during early morning and evening, like in other studies. Our study demonstrates that the proposed two-step framework can use unlabeled GPS tracking data to predict cattle behavior without human observations.

Testing personality-pace-of-life associations via artificial selection: insights from selected lines of rainbow trout on the context-dependence of correlations.

More than a decade of study since the personality pace-of-life syndrome (POLS) hypotheses were first proposed, there is little support for it within species. Lack of experimental control, insufficient sampling in the face of highly labile behavioural and metabolic traits, and context dependency of trait correlations are suggested as reasons. Here, I argue that artificial selection and/or use of existing selected lines represents a powerful but under-used approach to furthering our understanding of the POLS. To illustrate this potential, I conducted a focussed review of studies that compared the behaviour, metabolism, growth and survival of an artificially selected fast-growing rainbow trout relative to wild unselected strains, under varying food and risk conditions in the laboratory and field. Resting metabolic rate, food intake, and behaviours that enhance feeding but increase energy expenditure (activity, aggression, boldness), were all higher in the fast strain in paired contrasts, under all food and risk conditions, both in the laboratory and the field. Fast-strain fish grew faster in almost every food and risk situation except where food was highly limited (or absent), had higher survival under low or zero predation risk, but had lower survival under high risk. Several other traits rarely considered in POLS studies were also higher in the fast strain, including maximum swimming speed, and hormones (growth hormone (GH), thyroid hormone (T3) and insulin-like growth factor (IGF-1)). I conclude: (i) assumptions and predictions of the POLS hypothesis are well supported, and (ii) context-dependency was largely absent, but when present revealed trade-offs between food acquisition and predation risk. This focused review highlights the potential of artificial selection in testing POLS ideas, and will hopefully motivate further studies using other animals.

Spinal cord lesion MRI and behavioral outcomes in a miniature pig model of spinal cord injury: exploring preclinical potential through an ad hoc comparison with human SCI.

STUDY DESIGN: prospective case series of Yucatan miniature pig spinal cord contusion injury model with comparison to human cases of spinal cord injury (SCI). OBJECTIVES: to describe magnetic resonance imaging (MRI) measures of spinal cord lesion severity along with estimates of lateral corticospinal tracts spared neural tissue in both a less severe and more severe contusion SCI model, as well as to describe their corresponding behavioral outcome changes. SETTING: University laboratory setting. METHODS: Following a more severe and less severe SCI, each pig underwent spinal cord MRI to measure lesion characteristics, along with locomotor and urodynamics outcomes testing. RESULTS: In the pig with more severe SCI, locomotor and urodynamic outcomes were poor, and both the spinal cord lesion volume and damage estimates to the lateral corticospinal tracts were large. Conversely, in the pig with less severe SCI, locomotor and urodynamic outcomes were favorable, with the spinal cord lesion volume and damage estimates to the lateral corticospinal tracts being less pronounced. For two human cases matched on estimates of damage to the lateral corticospinal tract regions, the clinical presentations were similar to the pig outcomes, with more limited mobility and more limited bladder functional independence in the more severe case. CONCLUSIONS: Our initial findings contribute valuable insights to the emergent field of MRI-based evaluation of spinal cord lesions in pig models, offering a promising avenue for understanding and potentially improving outcomes in spinal cord injuries.

Emotional vocalizations alter behaviors and neurochemical release into the amygdala.

The basolateral amygdala (BLA), a brain center of emotional expression, contributes to acoustic communication by first interpreting the meaning of social sounds in the context of the listener's internal state, then organizing the appropriate behavioral responses. We propose that modulatory neurochemicals such as acetylcholine (ACh) and dopamine (DA) provide internal-state signals to the BLA while an animal listens to social vocalizations. We tested this in a vocal playback experiment utilizing highly affective vocal sequences associated with either mating or restraint, then sampled and analyzed fluids within the BLA for a broad range of neurochemicals and observed behavioral responses of adult male and female mice. In male mice, playback of restraint vocalizations increased ACh release and usually decreased DA release, while playback of mating sequences evoked the opposite neurochemical release patterns. In non-estrus female mice, patterns of ACh and DA release with mating playback were similar to males. Estrus females, however, showed increased ACh, associated with vigilance, as well as increased DA, associated with reward-seeking. Experimental groups that showed increased ACh release also showed the largest increases in an aversive behavior. These neurochemical release patterns and several behavioral responses depended on a single prior experience with the mating and restraint behaviors. Our results support a model in which ACh and DA provide contextual information to sound analyzing BLA neurons that modulate their output to downstream brain regions controlling behavioral responses to social vocalizations.

Estimates of the vitality and performances of Apis mellifera mellifera and hybrid honey bee colonies in Siberia: a 13-year study.

Honeybees display a great range of biological, behavioral, and economic traits, depending on their genetic origin and environmental factors. The high diversity of honeybees is the result of natural selection of specific phenotypes adapted to the local environment. Of particular interest is adaptation of local and non-local bee colonies to environmental conditions. To study the importance of genotype-environment interactions on the viability and productivity of local and non-local bee colonies, we analyzed the long-term dynamics of the main traits in dark forest bees (Apis mellifera mellifera) and hybrid colonies. From 2010 to 2022, a total of 64 colonies living in an apiary in Siberia, Russia, were monitored and tested to assess their biological, behavioral, and economic traits in a temperate continental climate. We detected significant correlations between the studied biological and behavioral indicators of the bee colony such as colony strength, overwintering ability, infection of colonies with diseases, hygienic behavior, and others. No relationships between the biological and economic (honey productivity) traits of bee colonies are shown. The overall result of our study is that local dark forest bee, A.m.mellifera, showed higher values for all analyzed traits than hybrid colonies. Compared to hybrids, dark forest bee colonies showed more gentleness, productivity, and survivorship. The results from our study indicate a specific local adaptation of the A.m.mellifera subspecies in a temperate continental climate. Siberia represents a unique region for the conservation of the dark forest bee. The creation of conservation areas is one way to protect local bee populations, well adapted to local environmental conditions, from uncontrolled importation of bee breeds from different regions.

Salivary oxytocin changes and effect of the season in sows kept in different farrowing systems: Farrowing crate and farrowing pen with temporary crating.

Alternative farrowing systems that have been developed in recent years could have a positive effect on the welfare of sows during farrowing and lactation. Oxytocin measurements in saliva may provide information about positive animal welfare status. The purpose of this study was to evaluate the changes in salivary oxytocin concentrations in sows during the lactation period in three different farrowing systems and in two different seasons. Crossbred Duroc sows (n = 34, average parity = 3.6 ± 1.80) were housed in conventional farrowing crates (FC) (n = 10) or in farrowing pens with temporary crating (TC), including SWAP (n = 12) and JFL15 (n = 12) in two different seasons: summer and winter. Saliva samples were collected for six days during lactation: days 2, 4, 12, 23, 25 (i.e., 1-day post-weaning) and 26 (i.e., 2-day post-weaning) after farrowing. Moreover, behavioral data from sows was recorded on days 2, 4, 12 and 23 after farrowing, using a 30-s scan sampling method for 3 min per pen to record the behaviors which were assessed by the same observer. The results showed that the salivary oxytocin concentrations were 472.5 pg/mL and 399.4 pg/mL higher in both TC (SWAP and JLF15, respectively) than in the FC in early-lactation period, and these differences were more pronounced in summer and at the end of lactation in winter. In terms of behavior, higher number of mother-young interactions were observed in TC than FC in early- and mid-lactation period. In conclusion, TC is associated to a higher salivary oxytocin concentration that could indicated an increased mother-young interaction, although oxytocin concentration can be influenced by other factors, such as season or day of lactation.

Keypoint-MoSeq: parsing behavior by linking point tracking to pose dynamics.

Keypoint tracking algorithms can flexibly quantify animal movement from videos obtained in a wide variety of settings. However, it remains unclear how to parse continuous keypoint data into discrete actions. This challenge is particularly acute because keypoint data are susceptible to high-frequency jitter that clustering algorithms can mistake for transitions between actions. Here we present keypoint-MoSeq, a machine learning-based platform for identifying behavioral modules ('syllables') from keypoint data without human supervision. Keypoint-MoSeq uses a generative model to distinguish keypoint noise from behavior, enabling it to identify syllables whose boundaries correspond to natural sub-second discontinuities in pose dynamics. Keypoint-MoSeq outperforms commonly used alternative clustering methods at identifying these transitions, at capturing correlations between neural activity and behavior and at classifying either solitary or social behaviors in accordance with human annotations. Keypoint-MoSeq also works in multiple species and generalizes beyond the syllable timescale, identifying fast sniff-aligned movements in mice and a spectrum of oscillatory behaviors in fruit flies. Keypoint-MoSeq, therefore, renders accessible the modular structure of behavior through standard video recordings.

Food quality influences behavioural flexibility and cognition in wild house mice.

Environmental change is frequent. To adjust and survive, animals need behavioural flexibility. Recently, cognitive flexibility has emerged as a driving force for adjusting to environmental change. Understanding how environmental factors, such as food quality, influence behavioural and/or more costly cognitive flexibility. Here, we investigate the effects of high-quality versus standard food as well as the effects of different housing conditions on both types of flexibility. Our results show that mice that experienced a poorer diet under seminatural conditions showed greater behavioural but not cognitive flexibility. For cage-housed mice, the results were less clear. However, mice fed a poorer diet performed better in innovative problem-solving, thus showing enhanced cognitive flexibility, which was not apparent in the reversal learning paradigm. The observed differences were most likely due to differences in motivation to obtain food rewards. Additionally, animals on poorer diet had lower brain volume, usually related to lower cognitive task performance at the between-species level. Thus, our study emphasises the importance of environmental conditions on behavioural flexibility at the within-species level, highlights that different test paradigms may lead to different conclusions, and finally shows that cage housing of wild animals may lead to patterns that do not necessarily reflect natural conditions.

Mice integrate conspecific and contextual information in forming social episodic-like memories under spontaneous recognition task conditions.

The ability to remember unique past events (episodic memory) may be an evolutionarily conserved function, with accumulating evidence of episodic-(like) memory processing in rodents. In humans, it likely contributes to successful complex social networking. Rodents, arguably the most used laboratory models, are also rather social animals. However, many behavioural paradigms are devoid of sociality, and commonly-used social spontaneous recognition tasks (SRTs) are open to non-episodic strategies based upon familiarity. We address this gap by developing new SRT variants. Here, in object-in-context SRTs, we asked if context could be specified by the presence/absence of either a conspecific (experiment 1) or an additional local object (experiment 2). We show that mice readily used the conspecific as contextual information to distinguish unique episodes in memory. In contrast, no coherent behavioural response emerged when an additional object was used as a potential context specifier. Further, in a new social conspecific-in-context SRT (experiment 3) where environment-based change was the context specifier, mice preferably explored a more recently-seen familiar conspecific associated with contextual mismatch, over a less recently-seen familiar conspecific presented in the same context. The results argue that, in incidental SRT conditions, mice readily incorporate conspecific cue information into episodic-like memory. Thus, the tasks offer different ways to assess and further understand the mechanisms at work in social episodic-like memory processing.

Effects of temporary access to environmental enrichment on measures of laboratory mouse welfare.

Laboratory mice are typically housed in "shoebox" cages with limited opportunities to engage in natural behaviour. Temporary access to environments with increased space and complexity (playpens) may improve mouse welfare. Previous work by our group has shown that mice are motivated to access and use these environments, but it is unknown how other aspects of welfare are impacted. Female C57BL/6J, BALB/cJ, and DBA/2J mice (n = 21; 7 mice per strain) were housed in mixed-strain trios and given temporary access to a large playpen with their cage mates three times per week. Control mice (n = 21; 7 mice per strain) remained in their home cages. Home cage behaviour (development of stereotypic behaviour over time, aggression following cage-changing) and anxiety tests were used to assess how playpen access impacted welfare. Contrary to our predictions, we found increased time spent performing stereotypies in playpen mice; this difference may be related to negative emotional states, increased motivation to escape the home cage, or active coping strategies. Playpen access resulted in strain-dependent improvements in aggression and some measures of anxiety. Aggression was lower for C57BL/6J mice in the playpen treatment following cage changing than it was for C57BL/6J control mice, while playpen mice, and particularly the C57BL/6J strain, spent more time in the center of the open field test and produced fewer fecal boli during anxiety testing, supporting other research showing that strain differences play an important role in behaviour and stress resiliency.

Watch out! High vigilance at small waterholes when alone in open trees.

An animal's environment contains many risks causing animals to scan their environment for potential predators and threats from conspecifics. How much time they invest in such vigilance depends on environmental and social factors. Most vigilance studies have been conducted in a foraging context with little known about vigilance in other contexts. Here we investigated vigilance of Gouldian finches at waterholes considering environmental and social factors. Gouldian finches are colour polymorphic with two main head colours in both sexes co-occurring in the same population, black-headed and red-headed. Data collection was done on birds sitting in trees surrounding waterholes by measuring the frequency of head movements, which reflects how frequently they change their field of view, i.e., scan different areas in their environment. A higher frequency generally reflects higher vigilance. Gouldian finches had a higher frequency of head movements when at small waterholes and when sitting in open, leafless trees. Moreover, head movements were higher when birds were alone in the tree as compared to groups of birds. Finally, birds in same head colour morph groups had a higher frequency of head movements than birds in mixed head colour groups. Results indicate heightened vigilance with increased perception of predation risk (small waterholes, open exposed perch, when alone) but that social vigilance also played a role (group composition) with particularly the aggressive red-headed birds being more vigilant when together with other red-headed birds. Future research should investigate the effect of smaller waterholes as global warming will cause smaller waterholes to become more common for longer periods of time, which can increase stress in the birds.

The complexity of tracking stegosaurs and their gregarious behavior.

Stegosaur tracks were unknown until the identification of Deltapodus more than 20 years ago. Currently, the Iberian Peninsula, especially Teruel Province, is one of the areas globally with the most occurrences of these tracks. However, their identification, based on the global record, is problematic due to their similarities with sauropod tracks. A review of the largest number of analyzed Deltapodus tracks globally, including the holotype of D. ibericus and a description of new occurrences, has been carried out. Our research shows substantial morphological variations, but all the studied tracks can be considered D. ibericus based on the manus morphology and the morphometric data. These variations are related to substrate differences and/or different dynamic foot postures (possibly ontogenetically related) during locomotion, as evidenced by changes within the same trackway. We provide detailed comparisons via 3D modeling with sauropod tracks, and our data show that they generally have proportionally longer manus and wider pes because of the differences in the metapodial bones. The scarcity of stegosaur trackways in the fossil record has prevented the identification of gregarious behavior in this group of herbivorous dinosaurs. Two of the studied tracksites show evidence of this behavior, being the only examples among stegosaurs described thus far in the fossil record.

Glial expression of a steroidogenic enzyme underlies natural variation in hitchhiking behavior.

Phoresy is an interspecies interaction that facilitates spatial dispersal by attaching to a more mobile species. Hitchhiking species have evolved specific traits for physical contact and successful phoresy, but the regulatory mechanisms involved in such traits and their evolution are largely unexplored. The nematode Caenorhabditis elegans displays a hitchhiking behavior known as nictation during its stress-induced developmental stage. Dauer-specific nictation behavior has an important role in natural C. elegans populations, which experience boom-and-bust population dynamics. In this study, we investigated the nictation behavior of 137 wild C. elegans strains sampled throughout the world. We identified species-wide natural variation in nictation and performed a genome-wide association mapping. We show that the variants in the promoter of nta-1, encoding a putative steroidogenic enzyme, underlie differences in nictation. This difference is due to the changes in nta-1 expression in glial cells, which implies that glial steroid metabolism regulates phoretic behavior. Population genetic analysis and geographic distribution patterns suggest that balancing selection maintained two nta-1 haplotypes that existed in ancestral C. elegans populations. Our findings contribute to further understanding of the molecular mechanism of species interaction and the maintenance of genetic diversity within natural populations.

Central amygdala CRF+ neurons promote heightened threat reactivity following early life adversity in mice.

Failure to appropriately predict and titrate reactivity to threat is a core feature of fear and anxiety-related disorders and is common following early life adversity (ELA). A population of neurons in the lateral central amygdala (CeAL) expressing corticotropin releasing factor (CRF) have been proposed to be key in processing threat of different intensities to mediate active fear expression. Here, we use in vivo fiber photometry to show that ELA results in sex-specific changes in the activity of CeAL CRF+ neurons, yielding divergent mechanisms underlying the augmented startle in ELA mice, a translationally relevant behavior indicative of heightened threat reactivity and hypervigilance. Further, chemogenic inhibition of CeAL CRF+ neurons selectively diminishes startle and produces a long-lasting suppression of threat reactivity. These findings identify a mechanism for sex-differences in susceptibility for anxiety following ELA and have broad implications for understanding the neural circuitry that encodes and gates the behavioral expression of fear.

Sex and Age Differences in Ontogeny of Alloparenting: A Relation to Forebrain DRD1, DRD2, and HTR2A mRNA Expression?

Alloparenting refers to the practice of caring for the young by individuals other than their biological parents. The relationship between the dynamic changes in psychological functions underlying alloparenting and the development of specific neuroreceptors remains unclear. Using a classic 10-day pup sensitization procedure, together with a pup preference and pup retrieval test on the EPM (elevated plus maze), we showed that both male and female adolescent rats (24 days old) had significantly shorter latency than adult rats (65 days old) to be alloparental, and their motivation levels for pups and objects were also significantly higher. In contrast, adult rats retrieved more pups than adolescent rats even though they appeared to be more anxious on the EPM. Analysis of mRNA expression using real-time-PCR revealed a higher dopamine D2 receptor (DRD2) receptor expression in adult hippocampus, amygdala, and ventral striatum, along with higher dopamine D1 receptor (DRD1) receptor expression in ventral striatum compared to adolescent rats. Adult rats also showed significantly higher levels of 5-hydroxytryptamine receptor 2A (HTR2A) receptor expression in the medial prefrontal cortex, amygdala, ventral striatum, and hypothalamus. These results suggest that the faster onset of alloparenting in adolescent rats compared to adult rats, along with the psychological functions involved, may be mediated by varying levels of dopamine DRD1, DRD2, and HTR2A in different forebrain regions.

Acute Stress Affects the Relaxin/Insulin-Like Family Peptide Receptor 3 mRNA Expression in Brain of Pubertal Male Wistar Rats.

The current literature suggests that relaxin-3/relaxin/insulin-like family peptide receptor 3 (RLN-3/RXFP-3) system is involved in the pathophysiology of affective disorders because the results of anatomical and pharmacological studies have shown that the RLN-3 signaling pathway plays a role in modulating the stress response, anxiety, arousal, depression-like behavior, and neuroendocrine homeostasis. The risk of developing mental illnesses in adulthood is increased by exposure to stress in early periods of life. The available data indicate that puberty is especially characterized by the development of the neural system and emotionality and is a "stress-sensitive" period. The presented study assessed the short-term changes in the expression of RLN-3 and RXFP-3 mRNA in the stress-dependent brain regions in male pubertal Wistar rats that had been subjected to acute stress. Three stressors were applied from 42 to 44 postnatal days (first day: a single forced swim; second day: stress on an elevated platform that was repeated three times; third day: restraint stress three times). Anxiety (open field, elevated plus maze test) and anhedonic-like behavior (sucrose preference test) were estimated during these tests. The corticosterone (CORT) levels and blood morphology were estimated. We found that the RXFP-3 mRNA expression decreased in the brainstem, whereas it increased in the hypothalamus 72 h after acute stress. These molecular changes were accompanied by the increased levels of CORT and anxiety-like behavior detected in the open field test that had been conducted earlier, that is, 24 h after the stress procedure. These findings shed new light on the neurochemical changes that are involved in the compensatory response to adverse events in pubertal male rats and support other data that suggest a regulatory interplay between the RLN-3 pathway and the hypothalamus-pituitary-adrenal axis activity in the mechanisms of anxiety-like behavior.

Correlation between bioluminescent blinks and swimming behavior in the splitfin flashlight fish Anomalops katoptron.

BACKGROUND: The light organs of the splitfin flashlight fish Anomalops katoptron are necessary for schooling behavior, to determine nearest neighbor distance, and to feed on zooplankton under dim light conditions. Each behavior is coupled to context-dependent blink frequencies and can be regulated via mechanical occlusion of light organs. During shoaling in the laboratory individuals show moderate blink frequencies around 100 blinks per minute. In this study, we correlated bioluminescent blinks with the spatio-temporal dynamics of swimming profiles in three dimensions, using a stereoscopic, infrared camera system. RESULTS: Groups of flashlight fish showed intermediate levels of polarization and distances to the group centroid. Individuals showed higher swimming speeds and curved swimming profiles during light organ occlusion. The largest changes in swimming direction occurred when darkening the light organs. Before A. katoptron exposed light organs again, they adapted a nearly straight movement direction. CONCLUSIONS: We conclude that a change in movement direction coupled to light organ occlusion in A. katoptron is an important behavioral trait in shoaling of flashlight fish.