nils-herrmann/clean_scirepeval huggingface dataset:
Gaze stabilization in mantis shrimp in response to angled stimuli
Venue: Journal of Comparative Physiology A

Gaze stabilization is a fundamental aspect of vision and almost all animals shift their eyes to compensate for any self-movement relative to the external environment. When it comes to mantis shrimp, however, the situation becomes complicated due to the complexity of their visual system and their range of eye movements. The stalked eyes of mantis shrimp can independently move left and right, and up and down, whilst simultaneously rotating about the axis of the eye stalks. Despite the large range of rotational freedom, mantis shrimp nevertheless show a stereotypical gaze stabilization response to horizontal motion of a wide-field, high-contrast stimulus. This response is often accompanied by pitch (up-down) and torsion (about the eye stalk) rotations which, surprisingly, have no effect on the performance of yaw (side-to-side) gaze stabilization. This unusual feature of mantis shrimp vision suggests that their neural circuitry for detecting motion is radially symmetric and immune to the confounding effects of torsional self-motion. In this work, we reinforce this finding, demonstrating that the yaw gaze stabilization response of the mantis shrimp is robust to the ambiguous motion cues arising from the motion of striped visual gratings in which the angle of a grating is offset from its direction of travel.
Effects of intracerebroventricular arginine vasotocin on a female amphibian proceptive behavior
Venue: Journal of Comparative Physiology A

Mate choice decisions of animals show significant variability—both among and within individuals. Clearly, such variability can profoundly impact individual fitness, as well as subtly alter sexual selection processes, but we know little about the neural mechanisms underlying such variability. We examined the influence of the neuropeptide arginine vasotocin (AVT) on the strength of attraction of female gray treefrogs (Hyla versicolor) showing positive phonotaxis to the call of a conspecific male. Female treefrogs received intracerebroventricular injections with either saline, AVT (five doses), or the AVT receptor antagonist Manning compound (two doses). By 30 min after injection, AVT significantly increased the speed with which females approached the speaker, at doses of 1, 10 and 50 ng per frog. At the highest dose, the average speed was doubled. The AVT antagonist significantly inhibited phonotaxis at both doses (50 and 100 ng). The effects of AVT on treefrog phonotaxis were shorter lived (disappearing within 60–90 min), compared to Manning compound (effects persisted at least 90 min). These findings support the hypothesis that endogenous AVT is critical to the display of female phonotaxis behavior. AVT may thus contribute to variability in female mate choices by modulating proceptive behaviors.
Within-winter flexibility in muscle and heart lipid transport and catabolism in passerine birds
Venue: Journal of Comparative Physiology B

Small birds in cold climates may show within-winter metabolic flexibility to match metabolic capacities to prevailing weather conditions. This flexibility may occur over periods of days to weeks, but the underlying mechanisms for such flexibility are not well understood. Because lipids are the primary fuel for sustained thermogenesis, we examined whether lipid transport and catabolism can mediate within-winter metabolic flexibility in two small temperate-zone wintering passerine birds, dark-eyed juncos (Junco hyemalis) and house sparrows (Passer domesticus). We used simple and multiple regression analyses to test for correlations of several lipid transporters in pectoralis muscle (plasma membrane-bound and cytosolic fatty acid-binding proteins, FABP; fatty acyl translocase, FAT/CD36) and regulatory enzymes (carnitine acyl transferase, CPT; β-hydroxyacyl CoA dehydrogenase, HOAD) in pectoralis and heart with short-term (ST, 0–7 days), medium-term (MT, 14–30 days) and long-term (LT, 30-year mean daily and extreme minimum temperatures, day of winter season) temperature variables. We hypothesized negative correlations between these regulators and temperature variables. Juncos showed negative correlations for FABPs with ST or MT temperature variables, but other lipid transporters and regulatory enzymes showed positive correlations with ST or MT temperatures for juncos, suggesting no consistent pathway-wide response to within-winter temperatures. LT temperature variables showed several significant associations with lipid transporters and enzymes for juncos, but also not in consistent directions. House sparrows showed the expected negative correlations with LT temperatures for FABPpm, but positive correlations with temperature variables for FABPc, CPT and HOAD. Different species-specific patterns of variation and the absence of consistent pathway-wide responses to temperature suggest that the lipid transport and catabolism pathway is not a uniform mediator of within-winter metabolic flexibility among small birds.
Effects of short- and long-term cold acclimation on morphology, physiology, and exercise performance of California mice (Peromyscus californicus): potential modulation by fatherhood
Venue: Journal of Comparative Physiology B

California mice (Peromyscus californicus) differ from most other mammals in that they are biparental, genetically monogamous, and (compared with other Peromyscus) relatively large. We evaluated effects of cold acclimation on metabolic rate, exercise performance, and morphology of pair-housed male California mice, as well as modulation of these effects by fatherhood. In Experiment 1, virgin males housed at 5° or 10 °C for approximately 25 days were compared with virgins housed at standard vivarium temperature of 22 °C. Measures included resting metabolic rate (RMR), maximal oxygen consumption ($$\dot{V}{\text{O}}_{2}$$V˙O2max), grip strength, and sprint speed. In Experiment 2, virgin males housed at 22 °C were compared with three groups of males housed at 10 °C: virgins, breeding males (housed with a female and their pups), and non-breeding males (housed with an ovariectomized, estrogen- and progesterone-treated female) after long-term acclimation (mean 243 days). Measures in this experiment included basal metabolic rate (BMR), $$\dot{V}{\text{O}}_{2}$$V˙O2max, maximal thermogenic capacity ($$\dot{V}{\text{O}}_{2}$$V˙O2sum), and morphological traits. In Experiment 1, virgin males housed at 5° and 10 °C had higher RMR and $$\dot{V}{\text{O}}_{2}$$V˙O2max than those at 22 °C. In Experiment 2, 10 °C-acclimated groups had shorter bodies; increased body, fat, and lean masses; higher BMR and $$\dot{V}{\text{O}}_{2}$$V˙O2sum, and generally greater morphometric measures and organ masses than virgin males at 22 °C. Among the groups housed at 10 °C, breeding males had higher BMR and lower $$\dot{V}{\text{O}}_{2}$$V˙O2max than non-breeding and/or virgin males. Overall, we found that effects of fatherhood during cold acclimation were inconsistent, and that several aspects of cold acclimation differ substantially between California mice and other small mammals.
The art of a hydraulic joint in a spider’s leg: modelling, computational fluid dynamics (CFD) simulation, and bio-inspired design
Venue: Journal of Comparative Physiology A

Important aspects of spider locomotion rely on a hydraulic mechanism. So far, this has not been theoretically analysed. In this work, the flow mechanism of a main hydraulic joint in a spider leg was studied. The purpose is to gain insight into a biohydraulic mechanism using an engineering approach to improve our understanding of the hemolymph flow path in the spider’s legs and to contribute to the theoretical analysis of the spider’s hydraulic transmission mechanism, thereby providing an inspiration for advanced biomimetic hydraulic systems. During the study, Micro-CT results were used to reconstruct the detailed flow channel. The high-pressure areas (inlet, joint, and closed leg end) and low pressures in between are also identified. Then, the internal flow field was investigated using computational fluid dynamics. At the same time, the method of dynamic mesh regeneration, elastic smoothing, is used to simulate muscle contraction and joint extension. The different functions of the channels are substantiated by the velocity profiles. Finally, a bionic hydraulic system was designed according to the trajectory of haemolymph in the flow channel.
A broad filter between call frequency and peripheral auditory sensitivity in northern grasshopper mice (Onychomys leucogaster)
Venue: Journal of Comparative Physiology A

Acoustic communication is a fundamental component of mate and competitor recognition in a variety of taxa and requires animals to detect and differentiate among acoustic stimuli (Bradbury and Vehrencamp in Principles of animal communication, 2nd edn., Sinauer Associates, Sunderland, 2011). The matched filter hypothesis predicts a correspondence between peripheral auditory tuning of receivers and properties of species-specific acoustic signals, but few studies have assessed this relationship in rodents. We recorded vocalizations and measured auditory brainstem responses (ABRs) in northern grasshopper mice (Onychomys leucogaster), a species that produces long-distance calls to advertise their presence to rivals and potential mates. ABR data indicate the highest sensitivity (28.33 ± 9.07 dB SPL re: 20 μPa) at 10 kHz, roughly corresponding to the fundamental frequency (11.6 ± 0.63 kHz) of long-distance calls produced by conspecifics. However, the frequency range of peripheral auditory sensitivity was broad (8–24 kHz), indicating the potential to detect both the harmonics of conspecific calls and vocalizations of sympatric heterospecifics. Our findings provide support for the matched filter hypothesis extended to include other ecologically relevant stimuli. Our study contributes important baseline information about the sensory ecology of a unique rodent to the study of sound perception.
Neurotoxicity of sodium salicylate to the spiral ganglion neurons: GABAA receptor regulates NMDA receptor by Fyn-dependent phosphorylation
Venue: Journal of Comparative Physiology A

The purpose of this study was to observe the regulatory effects of GABAA (γ-aminobutyric acid A) receptor on the N-methyl-d-aspartate (NMDA) receptor during excitotoxicity in spiral ganglion neurons in the rat cochlea induced by sodium salicylate (SS). Western blot illustrated SS decreased the expression of NMDA receptor 2B subunit (NR2B) surface protein through affecting GABAA receptor, but the total protein content did not significantly change. Y1472 and S1480 are important phosphorylation sites in NR2B, SS downregulated the Fyn-dependent phosphorylation of Y1472 in a manner not related to the CK2 (Casein Kinase 2) dependent phosphorylation of S1480, thus regulating the surface distribution and internalization of NMDA receptor through GABAA receptor. These results suggest that the modified pattern of dynamic balance between excitation and inhibition by coactivation of the GABAA receptor can attenuate the excitatory NMDA receptor under the action of SS, via inhibiting the Fyn-dependent phosphorylation of Y1472.
Adaptations in the call emission pattern of frugivorous bats when orienting under challenging conditions
Venue: Journal of Comparative Physiology A

Echolocating bats emit biosonar calls and use echoes arising from call reflections, for orientation. They often pattern their calls into groups which increases the rate of sensory feedback. Insectivorous bats emit call groups at a higher rate when orienting in cluttered compared to uncluttered environments. Frugivorous bats increase the rate of call group emission when they echolocate in noisy environments. In frugivorous bats, it remains unclear if call group emission represents an exclusive adaptation to avoid acoustic interference by signals of conspecifics or if it represents an adaptation that allows to orient under demanding environmental conditions. Here, we compared the emission pattern of the frugivorous bat Carolliaperspicillata when the bats were flying in narrow versus wide or cluttered versus non-cluttered corridors. The bats emitted larger call groups and they increased the call rate within call groups when navigating in narrow or cluttered environments. These adaptations resemble the ones shown when the bats navigate in noisy environments. Thus, call group emission represents an adaptive behavior when the bats orient in complex environments.
Coexisting lacertid lizard species Podarcis siculus and Podarcis melisellensis differ in dopamine brain concentrations
Venue: Journal of Comparative Physiology A

In the eastern Adriatic, Podarcis siculus, an invasive species, competitively excludes the native Podarcis melisellensis. Monoamine neurotransmitters—serotonin (5HT), dopamine (DA), and noradrenaline (NA)—are implicated in social behavior, and could lie at the basis of the direct behavioral interference of P. siculus with P. melisellensis. To understand the relationship between social behavior and monoamines, as well as the differences in behavior between P. siculus and P. melisellensis, we developed a high-performance liquid chromatography (UV/VIS detection) method with which we were able to reliably measure concentrations of 5HT, DA, and NA in 32 brains of the two lizard species. We observed no statistically significant influence of species, sex, or their interaction on brain NA and 5HT concentrations. Statistically significant influence of species on dopamine levels were recorded, with P. siculus having twice as much dopamine in their brains. Taking into account that a significant aggressive relationship, with P. siculus dominating over P. melisellensis, has been previously observed, and that dopamine directly influences this behavior, the observed differences in dopamine levels could represent a trait in these species and may contribute to the competitive exclusion of P. melisellensis by P. siculus in the eastern Adriatic.
Identification of the origin of force-feedback signals influencing motor neurons of the thoraco-coxal joint in an insect
Venue: Journal of Comparative Physiology A

Force feedback from Campaniform sensilla (CS) on insect limbs helps to adapt motor outputs to environmental conditions, but we are only beginning to reveal the neural control mechanisms that mediate these influences. We studied CS groups that affect control of the thoraco-coxal joint in the stick insect Carausius morosus by applying horizontal and vertical forces to the leg stump. Motor effects of ablation of CS groups were evaluated by recording extracellularly from protractor (ProCx) and retractor (RetCx) nerves. Extracellular recordings showed that the effects of stimulating the sensilla were consistent with their broad ranges of directional sensitivity: for example, RetCx firing in response to posterior bending could be reduced by ablating several groups of trochanteral CS, whereas ablation of tibial and femoral sensilla had little effect. In contrast, ProCx motor neuron activity upon anteriorly directed stimuli was affected mainly by ablating a single CS group (G2). Dye fills of trochanteral, femoral and tibial CS groups with fluorescent dyes revealed a common projection pattern with little group specificity. These findings support the idea that the influences of CS feedback are determined by the activities of pre-motor interneurons, facilitating fast and task-dependent adaptation to changing environmental conditions.
Straight-line orientation in the woodland-living beetle Sisyphus fasciculatus
Venue: Journal of Comparative Physiology A

To transport their balls of dung along a constant bearing, diurnal savannah-living dung beetles rely primarily on the sun for compass information. However, in more cluttered environments, such as woodlands, this solitary compass cue is frequently hidden from view by surrounding vegetation. In these types of habitats, insects can, instead, rely on surrounding landmarks, the canopy pattern, or wide-field celestial cues, such as polarised skylight, for directional information. Here, we investigate the compass orientation strategy behind straight-line orientation in the diurnal woodland-living beetle Sisyphus fasciculatus. We found that, when manipulating the direction of polarised skylight, Si. fasciculatus responded to this change with a similar change in bearing. However, when the apparent position of the sun was moved, the woodland-living beetle did not change its direction of travel. In contrast, the savannah-living beetle Scarabaeus lamarcki responded to the manipulation of the solar position with a corresponding change in bearing. These results suggest that the dominant compass cue used for straight-line orientation in dung beetles may be determined by the celestial cue that is most prominent in their preferred habitat.
Vitellogenesis in spiders: first analysis of protein changes in different reproductive stages of Polybetes pythagoricus
Venue: Journal of Comparative Physiology B

Vitellogenesis represents one of the most vital processes of oviparous species during which various proteins, carbohydrates, and lipids are synthesized and stored inside the developing oocytes. Through analyzing protein changes in the midgut diverticula, hemolymph, and ovaries of females throughout the different vitellogenic stages of the spider Polybetes pythagoricus, we determined the origin of the different proteins involved in the formation of lipovitellins (LVs) along with the existence of a linkage between the hemocyanin and this vital process. An increase in the total protein content of the midgut diverticula, hemolymph, and ovary occurred throughout vitellogenesis followed by a decrease in those levels after laying. The presence of hemocyanin in egg and in LV2, as well as its accumulation in the ovary throughout the vitellogenesis process, was determined. Considering that all biologic processes depend on the correct structure and function of proteins, this study establishes, for the first time for the Order Araneae, the coexistence of three different origins of vitellogenesis-related proteins: one predominantly ovarian involving peptides of 120, 75, 46, and 30 kDa; another extraovarian one originated from the midgut diverticula and represented by a 170 kDa peptide, and a third hemolymphatic one, represented by the 67 kDa peptide.
Molecular basis of the digestive functionality in developing Persian sturgeon (Acipenser persicus) larvae: additional clues for its phylogenetic status
Venue: Journal of Comparative Physiology B

Persian sturgeon (Acipenser persicus) is a critically endangered species, mainly due to overexploitation for its caviar. The permanence of populations of this species in the Caspian Sea is fully dependent on restocking programs. Accordingly, it is considered as an interesting target for aquaculture for both restocking and commercial purposes. In addition, as a Chondrostei, it exhibits one of the slowest rates of molecular evolution among vertebrates and is propounded as an excellent candidate for phylogenetic analysis and evolutionary biology. In this study, the early ontogeny of some key digestive enzymes precursors was determined at molecular level, aiming to obtain basic knowledge on the acquisition of digestive capacity of this species, and at the same time, to advance in its phylogenetic status from the point of view of digestion. For this purpose, A. persicus cDNAs for β-actin (actb; used as an internal reference gene), bile-salt activated lipase (cel), trypsinogen 1 (try1), pepsinogen (pga), and gastric proton pump (atp4a) were amplified and cloned, and their subsequent expressions were measured by quantitative real-time PCR during the first 34 days post hatch (dph). Two isoforms for pga and at least six for try1 were obtained in this study, probably due to the additional genome duplication which sturgeons suffered along evolution. Phylogenetic analysis of the deduced amino acids sequences from the studied genes demonstrated that this species has a close evolutionary distance to Holostei, coelacanths, and tetrapods, including amphibians, reptiles, birds and mammals. According to our results, expression of all the genes increased gradually over time and reached maximum levels around 18 dph. This pattern, which was comparable to length and weight data, could indicate that around 3 weeks after hatching, the digestive capacity of the Persian sturgeon changes from larval to juvenile mode.
Intertidal triplefin fishes have a lower critical oxygen tension (Pcrit), higher maximal aerobic capacity, and higher tissue glycogen stores than their subtidal counterparts
Venue: Journal of Comparative Physiology B

Decreased oxygen (O2) availability (hypoxia) is common in rock pools and challenges the aerobic metabolism of fishes living in these habitats. In this study, the critical O2 tension (Pcrit), a whole animal measure of the aerobic contribution to hypoxia tolerance, was compared between four New Zealand triplefin fishes including an intertidal specialist (Bellapiscis medius), an occasional intertidal inhabitant (Forsterygion lapillum) and two exclusively subtidal species (F. varium and F. malcolmi). The intertidal species had lower Pcrit values than the subtidal species indicating traits to meet resting O2 demands at lower O2 tensions. While resting O2 demand (standard metabolic rate; SMR) did not show a major difference between species, the intertidal species had higher maximal rates of O2 consumption ($$ \dot{M}{\text{O}}_{{2,}} $$M˙O2,max) and higher aerobic metabolic scope (MS). The high O2 extractive capacity of the intertidal species was associated with increased blood O2 carrying capacity (i.e., higher Hb concentration), in addition to higher mass-specific gill surface area and thinner gill secondary lamellae that collectively conveyed a higher capacity for O2 flux across the gills. The specialist intertidal species B. medius also had higher glycogen stores in both white muscle and brain tissues, suggesting a greater potential to generate ATP anaerobically and survive in rock pools with O2 tensions less than Pcrit. Overall, this study shows that the superior Pcrit of intertidal triplefin species is not linked to a minimisation of SMR, but is instead associated with an increased O2 extractive capacity of the cardiorespiratory system (i.e., $$ \dot{M}{\text{O}}_{{2,}} $$M˙O2,max, MS, Hb and gill O2 flux).
Image statistics of the environment surrounding freely behaving hoverflies
Venue: Journal of Comparative Physiology A

Natural scenes are not as random as they might appear, but are constrained in both space and time. The 2-dimensional spatial constraints can be described by quantifying the image statistics of photographs. Human observers perceive images with naturalistic image statistics as more pleasant to view, and both fly and vertebrate peripheral and higher order visual neurons are tuned to naturalistic image statistics. However, for a given animal, what is natural differs depending on the behavior, and even if we have a broad understanding of image statistics, we know less about the scenes relevant for particular behaviors. To mitigate this, we here investigate the image statistics surrounding Episyrphus balteatus hoverflies, where the males hover in sun shafts created by surrounding trees, producing a rich and dense background texture and also intricate shadow patterns on the ground. We quantified the image statistics of photographs of the ground and the surrounding panorama, as the ventral and lateral visual field is particularly important for visual flight control, and found differences in spatial statistics in photos where the hoverflies were hovering compared to where they were flying. Our results can, in the future, be used to create more naturalistic stimuli for experimenter-controlled experiments in the laboratory.