Changes In Animal Behavior Research Articles

The Herbicide Glyphosate and Its Formulations Impact Animal Behavior across Taxa

Use of glyphosate and glyphosate-based herbicides is ubiquitous in US agriculture and widespread around the world. Despite marketing efforts to the contrary, numerous studies demonstrate glyphosate toxicity to non-target organisms including animals, primarily focusing on mortality, carcinogenicity, renal toxicity, reproductive, and neurological toxicity, and the biochemical mechanisms underlying these physiological outcomes. Glyphosate toxicity also impacts animal behavior, both in model systems and in agricultural and environmentally relevant contexts. In this review, we examine the effects of glyphosate and glyphosate-based herbicides on animal behaviors, particularly activity, foraging and feeding, anti-predator behavior, reproductive behaviors, learning and memory, and social behaviors. Glyphosate can be detected both in food and in the environment, and avoided through activity and feeding strategies. However, exposure also reduces activity, depresses foraging and feeding, increases susceptibility to predation, interferes with courtship, mating, fertility and maternal behaviors, decreases learning and memory capabilities, and disrupts social behaviors. Changes in animal behavior as a result of glyphosate toxicity are important because of their sometimes severe effects on individual fitness, as well as ecosystem health. Implications for human behavior are also considered.

Effect of estradiol and predator cues on behavior and brain responses of captive female house sparrows (Passer domesticus).

The presence of predators can cause major changes in animal behavior, but how this interacts with hormonal state and brain activity is poorly understood. We gave female house sparrows (Passer domesticus) in post-molt condition an estradiol (n = 17) or empty implant (n = 16) for 1week. Four weeks after implant removal, a time when female sparrows show large differences in neuronal activity to conspecific vs. heterospecific song, we exposed birds to either 30min of conspecific song or predator calls, and video recorded their behavior. Females were then euthanized, and we examined neuronal activity using the expression of the immediate early gene (IEG) ZENK to identify how the acoustic stimuli affected neuronal activation. We predicted that if female sparrows with estradiol implants reduce neuronal activity in response to predator calls as they do to neutral tones and non-predatory heterospecifics, they would show less fear behavior and a decreased ZENK response in brain regions involved in auditory (e.g., caudomedial mesopallium) and threat perception functions (e.g., medial ventral arcopallium) compared to controls. Conversely, we predicted that if females maintain auditory and/or brain sensitivity towards predator calls, then female sparrows exposed to estradiol would not show any differences in ZENK response regardless of playback type. We found that female sparrows were less active during predator playbacks independent of hormone treatment and spent more time feeding during conspecific playback if they had previously been exposed to estradiol. We observed no effect of hormone or sound treatment on ZENK response in any region of interest. Our results suggest that female songbirds maintain vigilance towards predators even when in breeding condition.

Pharmacological Evaluation of Benincasa Hispida Cogn. Fruit on Chronic Foot Shock Induced Stress in Mice

Stress can be defined as a brain-body reaction towards stimuli arising from the environment or from internal cues that are interpreted as a disruption of homeostasis. A number of reports indicated that treatment with herbal plant extracts could lead to a significant reduction in stress. The aim of this study was to evaluate the antistress activity through Inescapable electric chronic foot shock model in mice and to assess the effect of extract on stress induced behavioral changes in animals and to determine the efficiency of Benincasa hispida Cogn. Extract on Motor activity and Elevated plus maze to assess anxiety. In this study, mice were divided into five groups with five animals each. The first group received ip dose of the vehicle saline (2ml/kg). The second group received diazepam 1mg/kg ip along with foot shock. Third, fourth, and fifth groups received oral dose of 100, 200, and 400 mg /kg of fruit extract of Benincasa hispida along with foot shock. Inescapable electricFoot-shocks (intensity 0.8mA, interval: 10sec, duration:10sec) were delivered through a grid floor once daily for 21 days. The results showed that Benincasa hispida extract (200 and 400mg/kg) was found to have an antistress effect. The dose of Benincasa hispida extract (200 and 400mg/kg), increased entries into open arm and the time spend in open arm on the elevated plus maze test indicate that extract reduced the stress level and it significantly reduced the spontaneous motor activity and decreased the anxiety. The results suggest that the ethanolic extract of Benincasa hispida has potential antistress effect that can be explored for therapeutic advantage as an alternative treatment in medical conditions.

Tracing energy inputs into the seafloor using carbonate sediments

Carbonate rocks provide unique and valuable sedimentary archives for secular changes in Earth's physical, chemical, and biological processes. However, reading the stratigraphic record produces overlapping, nonunique interpretations that stem from the difficulty in directly comparing competing biological, physical, or chemical mechanisms within a common quantitative framework. We built a mathematical model that decomposes these processes and casts the marine carbonate record in terms of energy fluxes across the sediment-water interface. Results showed that physical, chemical, and biological energy terms across the seafloor are subequal and that the energetic dominance of different processes varies both as a function of environment (e.g., onshore vs. offshore) as well as with time-varying changes in seawater chemistry and with evolutionary changes in animal abundance and behavior. We applied our model to observations from the end-Permian mass extinction-a massive upheaval in ocean chemistry and biology-revealing an energetic equivalence between two hypothesized drivers of changing carbonate environments: a reduction in physical bioturbation increased carbonate saturation states in the oceans. Early Triassic occurrences of 'anachronistic' carbonates-facies largely absent from marine environments after the Early Paleozoic-were likely driven more by reduction in animal biomass than by repeated perturbations to seawater chemistry. This analysis highlighted the importance of animals and their evolutionary history in physically shaping patterns in the sedimentary record via their impact on the energetics of marine environments.

The influence of human activity on predator-prey spatiotemporal overlap.

Despite growing evidence of widespread impacts of humans on animal behaviour, our understanding of how humans reshape species interactions remains limited. Here, we present a framework that draws on key concepts from behavioural and community ecology to outline four primary pathways by which humans can alter predator-prey spatiotemporal overlap. We suggest that predator-prey dyads can exhibit similar or opposite responses to human activity with distinct outcomes for predator diet, predation rates, population demography and trophic cascades. We demonstrate how to assess these behavioural response pathways with hypothesis testing, using temporal activity data for 178 predator-prey dyads from published camera trap studies on terrestrial mammals. We found evidence for each of the proposed pathways, revealing multiple patterns of human influence on predator-prey activity and overlap. Our framework and case study highlight current challenges, gaps, and advances in linking human activity to animal behaviour change and predator-prey dynamics. By using a hypothesis-driven approach to estimate the potential for altered species interactions, researchers can anticipate the ecological consequences of human activities on whole communities.

ДОЛГОСРОЧНЫЕ ИЗМЕНЕНИЯ ВПОВЕДЕНИИ И НЕЙРОХИМИЧЕСКИХ ОСОБЕННОСТЯХ РАБОТЫ ГОЛОВНОГО МОЗГА КРЫС ПОСЛЕ КОМБИНИРОВАННОГО ВОЗДЕЙСТВИЯ ГИПОГРАВИТАЦИИ И ИОНИЗИРУЮЩИХ ИЗЛУЧЕНИЙ, МОДЕЛИРУЕМЫХ В НАЗЕМНОМ ЭКСПЕРИМЕНТЕ

We investigated the effects of combined exposure to hypogravity and ionizing radiations on neurochemical processes in key structures of the rat's brain leading to long dated changes in behavior. The authoring procedure consisted of a synchronous combination of chronic tail-suspension, gamma- irradiation and irradiation by 12С ions in an effort to extrapolate results of the ground-based experiment on real spaceflight conditions (Mars mission). The modeled factors brought about significant changes in animal behavior and metabolism of neuromediators that persisted for several months, that is roughly a quarter of this animal's life. The behavior analysis (Morris labyrinth) suggests sustained major disorders in spatial memory and orientation. Data of neurochemical analysis demonstrate also lasting shifts in dopamine metabolism.

Effect of starvation on electrotaxis response.

Caenorhabditis elegans is an ideal model for investigating the effects of extrinsic and intrinsic conditions on the behavioral changes of animals. Our group previously showed how different conditions influence the behavior of worms following an electric stimulus in a microfluidic channel, known as electrotaxis. In this study we describe the effect of starvation on the electrotaxis movement of animals. We show that acute starvation did not affect the electrotaxis response or dopaminergic neurons but extended the lifespan of animals.

When humans play evolutionary games with animal species

Taking into account of a rapidly growing literature studying the negative effects of changes in animal behaviour induced by human activities on ecological dynamics, biodiversity preservation, and human well-being, we model the interaction between a population of humans and a population of animals by means of an evolutionary game. In such a game, we assume that humans can adopt two alternative behaviours (strategies), one with a high environmental impact (HI) and the other with a low impact (LI). Animals also have two alternative behaviours: they can behave in a typical (T) or non-typical (NT) way. The former corresponds to the natural strategy animals would typically adopt in the absence of human interference (e.g. hunting prey) while the latter can be seen as an adaptive behaviour adopted by animals to defend themselves from the negative consequences of human action, or to opportunistically benefit of food resources that human activity may provide as a by-product. The analysis of our model shows that the adoption process of the strategies HI, LI, NT, T can generate a great variety of dynamic regimes, even if the ecological context we consider is very simple. The main purpose of this work is to propose a new research line in ecological modelling and to highlight a policy issue that has been largely ignored thus far: how to link the battle against biodiversity loss with the fight against species behavioural typicality loss.

Toxicological characteristics of the injectable form of copper nanopowder

The toxicological characteristics of the injection form of copper nanopowder are presented. The studied compound was administered in carts of 500 mg /kg (group 2 animals), 1000 mg/kg (group 3 animals), 2000 mg/kg (group 4 animals), 3000 mg/kg (group 5 animals) and 5000 mg/kg (group 6 animals). Animals of the control group (group 1) were injected with an appropriate amount of solvent (propylene glycol). The volume of the injected compound did not exceed 5 ml. It was found that after administration of the studied compound at doses of 500 and 1000 mg/kg, there were no clinical manifestations of intoxication in white rats. With an increase in doses up to 2000 – 5000 mg / kg of body weight, anxiety, difficulty breathing, and tremor were observed. However, according to the results of the experiment, we did not establish a lethal dose of the drug. When studying the chronic toxicity of the drug, negative changes in animal behavior were observed for 14 days. During the whole time of the experiment, for some time there were not coordinated and coordinated movements. There was no paralysis. The mucous membranes were pink in color without pathological changes. Throughout the entire time of the research, the animals reacted to external (sound) stimuli. A decrease or lack of appetite was observed an hour after administration of the drug and lasted for 6 days, then returned to normal. Thus, the studied compound can be attributed to hazard class IV and to the group of low-toxic substances in accordance with GOST 12.1.007-76.

Under the influence of light: How light pollution disrupts personality and metabolism in hermit crabs

Anthropogenic disturbances are known to cause significant physiological and behavioural changes in animals and, thus, are the critical focus of numerous studies. Light pollution is an increasingly recognised source of disturbance that has the potential to impact animal physiology and behaviour. Here, we investigate the effect of constant light on a personality trait and metabolic rate in the European hermit crab Pagurus bernhardus. We used Bayesian mixed models to estimate average behavioural change (i.e. sample mean level behavioural plasticity) and between- and within-individual variation in boldness in response to laboratory light. Hermit crabs experiencing constant light were consistently less bold and had a higher metabolic rate than those kept under a standard laboratory light regime (12:12 h light/dark). However, there was no effect of light on individual consistency in behaviour. As boldness is associated with coping with risk, hermit crabs exposed to light pollution at night may experience increased perceived predation risk, adjusting their behaviour to compensate for the increased conspicuousness. However, reduced boldness could lead to lower rates of foraging and this, in combination with elevated metabolic rate, has the potential for a reduction in energy balance.

Transcription Factors as Important Regulators of Changes in Behavior through Domestication of Gray Rats: Quantitative Data from RNA Sequencing.

Studies on hereditary fixation of the tame-behavior phenotype during animal domestication remain relevant and important because they are of both basic research and applied significance. In model animals, gray rats Rattus norvegicus bred for either an enhancement or reduction in defensive response to humans, for the first time, we used high-throughput RNA sequencing to investigate differential expression of genes in tissue samples from the tegmental region of the midbrain in 2-month-old rats showing either tame or aggressive behavior. A total of 42 differentially expressed genes (DEGs; adjusted p-value < 0.01 and fold-change > 2) were identified, with 20 upregulated and 22 downregulated genes in the tissue samples from tame rats compared with aggressive rats. Among them, three genes encoding transcription factors (TFs) were detected: Ascl3 was upregulated, whereas Fos and Fosb were downregulated in tissue samples from the brains of tame rats brain. Other DEGs were annotated as associated with extracellular matrix components, transporter proteins, the neurotransmitter system, signaling molecules, and immune system proteins. We believe that these DEGs encode proteins that constitute a multifactorial system determining the behavior for which the rats have been artificially selected. We demonstrated that several structural subtypes of E-box motifs—known as binding sites for many developmental TFs of the bHLH class, including the ASCL subfamily of TFs—are enriched in the set of promoters of the DEGs downregulated in the tissue samples of tame rats’. Because ASCL3 may act as a repressor on target genes of other developmental TFs of the bHLH class, we hypothesize that the expression of TF gene Ascl3 in tame rats indicates longer neurogenesis (as compared to aggressive rats), which is a sign of neoteny and domestication. Thus, our domestication model shows a new function of TF ASCL3: it may play the most important role in behavioral changes in animals.

Intensive hunting changes human-wildlife relationships.

Wildlife alter their behaviors in a trade-off between consuming food and fear of becoming food themselves. The risk allocation hypothesis posits that variation in the scale, intensity and longevity of predation threats can influence the magnitude of antipredator behavioral responses. Hunting by humans represents a threat thought to be perceived by wildlife similar to how they perceive a top predator, although hunting intensity and duration varys widely around the world. Here we evaluate the effects of hunting pressure on wildlife by comparing how two communities of mammals under different management schemes differ in their relative abundance and response to humans. Using camera traps to survey wildlife across disturbance levels (yards, farms, forests) in similar landscapes in southern Germany and southeastern USA, we tested the prediction of the risk allocation hypothesis: that the higher intensity and longevity of hunting in Germany (year round vs 3 months, 4x higher harvest/km2/year) would reduce relative abundance of hunted species and result in a larger fear-based response to humans (i.e., more spatial and temporal avoidance). We further evaluated how changes in animal abundance and behavior would result in potential changes to ecological impacts (i.e., herbivory and predation). We found that hunted species were relatively less abundant in Germany and less associated with humans on the landscape (i.e., yards and urban areas), but did not avoid humans temporally in hunted areas while hunted species in the USA showed the opposite pattern. These results are consistent with the risk allocation hypothesis where we would expect more spatial avoidance in response to threats of longer duration (i.e., year-round hunting in Germany vs. 3-month duration in USA) and less spatial avoidance but more temporal avoidance for threats of shorter duration. The expected ecological impacts of mammals in all three habitats were quite different between countries, most strikingly due to the decreases in the relative abundance of hunted species in Germany, particularly deer, with no proportional increase in unhunted species, resulting in American yards facing the potential for 25x more herbivory than German yards. Our results suggest that the duration and intensity of managed hunting can have strong and predictable effects on animal abundance and behavior, with the potential for corresponding changes in the ecological impacts of wildlife. Hunting can be an effective tool for reducing wildlife conflict due to overabundance but may require more intensive harvest than is seen in much of North America.

Structural changes of erythrocyte membrane revealed by 3D confocal optical profilometer.

We examined hematological changes influenced by the experimental hypervitaminosis A. The 3D confocal optical profilometer was applied for assessment of the erythrocytes' membrane structural changes influenced by an overdose of vitamin A. The blood smears were evaluated in terms of alterations of geometrical and optical parameters of erythrocytes for two groups of animals: oil base and retinol palmitate (n=9 animals for each group). The results demonstrate that an overdose of retinol palmitate causes changes in the torus curvature and pallor of discocytes, their surface area and volume. The observed structural malformations of the shape of red blood cells become visible at the earlier preclinical stage of changes in animal state and behavior. With this in mind, the results of the study open a new area of research in the certain dysfunction diagnosis of red blood cells and have a great potential in the further development of new curative protocols.

EFFECTS OF MORINDA CITRIFOLIA LINN (NONI) AND TAHITIAN NONI® JUICE (TNJ) ON LOCOMOTOR ACTIVITY IN MICE

Noni fruit extract and juice (Morinda citrifolia L., Family: Rubiaceae) had long been known as a medicinal plant in folklore medicine in tropical countries and Pacific islands. To date, the available scientific knowledge was focused on different pharmacological effects. It was claimed to have a beneficial effect on drug addiction by Noni fruit extract and its juice in animal studies. Keeping this in mind we investigated whether the noni fruit extract and noni beverages contained any effect on locomotion in mice using Actimeter (a standard test for locomotor activity). We found that the administration of a single dose of Morinda citrifolia extract (MMC) at varying doses (0.5, 1, 3, and 5 g/kg p.o.) 60 min before the testing and Tahitian noni juice (TNJ) 100% made available as a source of drinking water for a period of 24 hours before the test day produced no significant effect on animal’s locomotion and behavior when compared with the control group. The extract did not exhibit any toxic effects. There was no mortality and change in animal behavior seen. The current results suggest that MMC and TNJ are safe and can be utilized for further neuropharmacological research.

Reef fishes weaken dietary preferences after coral mortality, altering resource overlap.

The direct and indirect effects of climate change can affect, and are mediated by, changes in animal behaviour. However, we often lack sufficient empirical data to assess how large-scale disturbances affect the behaviour of individuals, which scales up to influence communities. Here, we investigate these patterns by focusing on the foraging behaviour of butterflyfishes, prominent coral-feeding fishes on coral reefs, before and after a mass coral bleaching event in Iriomote, Japan. In response to 65% coral mortality, coral-feeding fishes broadened their diets, showing a significant weakening of dietary preferences across species. Multiple species reduced their consumption of bleaching-sensitive Acropora corals, while expanding their diets to consume a variety of other coral genera. This resulted in decreased dietary overlap among butterflyfishes. Behavioural changes in response to bleaching may increase resilience of coral reef fishes in the short term. However, coral mortality has reduced populations of coral-feeders world-wide, indicating the changes in feeding behaviour we document here may not be sufficient to ensure long-term resilience of butterflyfishes on coral reefs.

Inducible Nitric Oxide Synthase Inhibition in the Medial Prefrontal Cortex Attenuates the Anxiogenic-Like Effect of Acute Restraint Stress via CB1 Receptors.

Stress exposure can result in several proinflammatory alterations in the brain, including overexpression of the inducible isoform of nitric oxide synthase (iNOS) in the medial prefrontal cortex (mPFC). These changes may be involved in the development of many psychiatric conditions. However, it is unknown if iNOS in mPFC plays a significant role in stress-induced behavioral changes. The endocannabinoid (ECB) system is also influenced by stress. Its activation seems to be a counter regulatory mechanism to prevent or decrease the stress-mediated neuroinflammatory consequences. However, it is unclear if the ECB system and iNOS interact to influence stress consequences. This study aimed to test the hypothesis that the anti-stress effect of iNOS inhibition in mPFC involves the local ECB system, particularly the CB1 cannabinoid receptors. Male Wistar rats with guide cannula aimed at the mPFC were submitted to acute restraint stress (RS) for 2 h. In the following morning, rats received bilateral microinjections of vehicle, AM251 (CB1 antagonist; 100 pmol), and/or 1400W (iNOS selective inhibitor; 10−4, 10−3, or 10−2 nmol) into the prelimbic area of mPFC (PL-mPFC) before being tested in the elevated plus-maze (EPM). iNOS inhibition by 1400W prevented the anxiogenic-like effect observed in animals submitted to RS. The drug did not promote behavior changes in naive animals, demonstrating a stress-dependent effect. The 1400W-anti-stress effect was prevented by local pretreatment with AM251. Our data suggest that iNOS inhibition may facilitate the local endocannabinoid signaling, attenuating stress effects.

Mediterranean Diet Reduces Social Isolation and Anxiety in Adult Female Nonhuman Primates

Dietary composition is associated with the differential prevalence of psychiatric disorders; the Western diet confers increased risk, while the Mediterranean diet appears to reduce risk. In nonhuman primates, anxiety-like behaviors and social isolation have been linked to both Western diet consumption and increased inflammatory disease risk, and recent evidence suggests that diet composition may affect immune system function in part through its effects on behavior. This is particularly important in the context of the global COVID-19 pandemic in which social isolation has been associated with disease. Here, we examined the effects of Western- and Mediterranean-like diets on social behavior in a randomized, 34-month preclinical trial in middle-aged female cynomolgus macaques (Macaca fascicularis). Diet induced rapid and persistent changes in a suite of behaviors. After just three months of experimental diet consumption, a composite measure of diet-altered behavior (DAB) significantly differed between the two diets (p = 0.014) and remained different throughout the 24-month experimental observation period (p = 2.2 × 10−8). Monkeys fed the Western diet spent more time alone (FDR = 4.4 × 10−5) and displayed more anxiety behavior (FDR = 0.048), whereas monkeys fed the Mediterranean diet spent more time resting (FDR = 0.0013), attentive (FDR = 0.017), and in body contact with groupmates (FDR = 4.1 × 10−8). These differences were largely due to changes in behavior of animals fed the Mediterranean diet, while Western-diet-fed-animals exhibited similar behaviors compared to the eight-month baseline period, during which all monkeys consumed a common laboratory diet. These observations provide experimental support in a nonhuman primate model, demonstrating a potential therapeutic benefit of the Mediterranean diet consumption to reduce social isolation and anxiety and thus mitigate social isolation-associated disorders that often accompany illness and disability.

Comparative Lipidomic and Metabolomic Analyses Reveal the Mystery of Lacquer Oil from Toxicodendron vernicifluum for the Treatment of "Yuezi" Disease in Nujiang, China: From Anti-Inflammation and Anti-Postpartum Depression Perspective.

Background: In southwest China, especially in Nujiang, lacquer oil from the drupes of Toxicodendron vernicifluum (Stokes) F. A. Barkley, including black lacquer oil (BLO) and white lacquer oil (WLO), is one of the most important edible oils for the local people. Through the field investigation, the locals believe that lacquer oil has benefits for parturient women and for the treatment of “Yuezi” disease. However, studies on bioactivities and the chemical compositions of lacquer oil are limited. Purpose: This study was designed to reveal the mystery of lacquer oil for the treatment of “Yuezi” disease by testing its anti-inflammatory and anti-postpartum depressant activities and related bioactive compounds. Methods: The anti-inflammatory effects of lacquer oil were examined by establishing a lipopolysaccharide (LPS)-induced RAW264.7 cell inflammation model and detecting the level of pro-inflammatory factors such as NO, IL-6 and TNF-α. The antidepressant effects of lacquer oil were studied by building a mouse model of postpartum depression (PPD), and the animal behavior changes of PPD model mice were assessed by open field test (OFT), forced swimming test (FST) and tail suspension test (TST). The chemical profiles of BLO and WLO were detected by lipidomic and the untargeted metabolomic research methods based on UPLC-MS/MS. Results: The results showed that BLO and WLO exerted anti-inflammatory effects by reducing the release of pro-inflammatory factors and BLO had better anti-inflammatory effects than WLO. While only BLO had anti-postpartum depressant activities, as evidenced by the significantly reduced the immobility time of the BLO-treated PPD mice in TST and FST compared to the PPD model mice. The comparative lipidomic analysis revealed that BLO contained high levels of Diacylglycerols (DAG) and Diacylglyceryl trimethylhomoserines (DGTS) but low level of ceramides (Cer), sphingomyelines (SM), phosphatidylcholines (PC) and phosphatidylethanolamines (PE) compared with WLO. Metabolomics analysis showed that there were 57 chemical markers between BLO and WLO, of which 17 potential biomarkers have been declared to possess anti-inflammatory and/or antidepressant activities. Conclusion: The findings of this study furnish a scientific support for the traditional uses of lacquer oil for the treatment of “Yuezi” disease from anti-inflammation and anti-postpartum depression perspective.

An extended amygdala-midbrain circuit controlling cocaine withdrawal-induced anxiety and reinstatement.

SUMMARYAlthough midbrain dopamine (DA) circuits are central to motivated behaviors, our knowledge of how experience modifies these circuits to facilitate subsequent behavioral adaptations is limited. Here we demonstrate the selective role of a ventral tegmental area DA projection to the amygdala (VTADA→amygdala) for cocaine-induced anxiety but not cocaine reward or sensitization. Our rabies virus-mediated circuit mapping approach reveals a persistent elevation in spontaneous and task-related activity of inhibitory GABAergic cells from the bed nucleus of the stria terminalis (BNST) and downstream VTADA→amygdala cells that can be detected even after a single cocaine exposure. Activity in BNSTGABA→midbrain cells is related to cocaine-induced anxiety but not reward or sensitization, and silencing this projection prevents development of anxiety during protracted withdrawal after cocaine administration. Finally, we observe that VTADA→amygdala cells are strongly activated after a challenge exposure to cocaine and that activity in these cells is necessary and sufficient for reinstatement of cocaine place preference.

Blood and Bone, Tears and Oil

Abstract In the seventeenth century, the climate of the Arctic cooled, warmed briefly, and cooled again, just as European merchants established new industries to extract the region’s resources. Few were larger or more violent than the whaling industry that exploited bowhead whales between Jan Mayen and Svalbard. This article argues that linked changes in climate and animal behavior influenced violence among whalers in different ways during three stages of the seventeenth-century industry. In the first, cooling discouraged violence by increasing the regional extent of sea ice, which led both whales and whalers to congregate in tight quarters, raising the cost of hostilities among whalers. In the second, violence provoked attempts to colonize fortified whaling stations year-round, leading to a shift in polar bear behavior and exposing overwintering whalers to some of the coldest weather of the Little Ice Age in the Arctic. In the third, sweeping changes in climate and whale culture helped doom whaling companies and their fortified whaling stations, while encouraging open-sea whaling that transformed where and how whalers could fight one another. This article reveals, above all, the potential of combining climate history with animal-human history to provide fresh perspectives on the past, present, and future.