Brown and white egg-layer strain differences in fearfulness and stress measures

Photo-incubation can influence the fear and stress responses of poultry. However, it is unclear how photo-stimulation initiated at different phases of development influences the welfare status of slow-growing broiler birds. 500 Sasso eggs were assigned to 4 treatments; some were incubated in the dark throughout incubation (TA), while TB, TC and TD were photo-stimulated (12L:12D) from days 1, 7, and 14 of incubation, respectively, until hatch using a 6,500k LED at 788 clux intensity. Birds were raised in 5 replicates per treatment with 16 birds per replicate using a 6,500k LED (at 28 clux) and a photoperiod of 16L:8D. Fear (emergence, tonic immobility, isolation and inversion tests) and stress response (physical asymmetry) of 10 birds per treatment were examined. At the end of the three-week brooding, all parameters measured were not significantly influenced (P > 0.05) by the onset of photo-incubation. At slaughter age (12 weeks), physical asymmetry was significantly higher (P < 0.05) in TA compared to the other treatments. The frequency of isolation vocalisation was significantly lower (P < 0.05) in TB compared to TA, and latency to rightness during tonic immobility was significantly higher (P < 0.05) in TA compared to the other treatments. Latency to emerge was significantly longer (P < 0.05) in TA compared to TC and TD. The frequency of wing flaps during inversion was significantly higher (P < 0.05) in TA and TD. Conclusively, photo-incubating eggs reduce stress and fear, and initiating photo-incubation during the first phase of incubation is more beneficial.

Temperamental turkeys: Reliability of behavioural responses to four tests of fear

Effects of tonic immobility (TI) and corticosterone (CORT) on energy status and protein metabolism in pectoralis major muscle of broiler chickens

Corticosterone microinjected into nucleus pontis oralis increases tonic immobility in rats

Neonatal exposure to low dose corticosterone persistently modulates hippocampal mineralocorticoid receptor expression and improves locomotor/exploratory behaviour in a mouse model of Rett syndrome

9.P5. Effect of the odor of predator and the role of olfactory system in the modulation of tonic immobility in the toad Bufo paracnemis

Tonic immobility (TI) is considered to be an innate fear response characterized by a temporary state of profound and reversible motor inhibition. TI occurs in a wide range of species in a predator-prey confrontation and is hypothesized to be a terminal defence response occurring when there is physical contact between prey and predator. The objective of the present study was to investigate the validity of the TI model in guinea pigs for detection of anxiolytic and/or antidepressant drug activity. Compounds that reduced TI include the serotonin (5-HT) releaser fenfluramine, the 5-HT(1A) receptor agonists 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) and buspirone, the 5-HT(2C/2B) receptor antagonist SB206553, the 5-HT(2A) receptor antagonist MDL 100.151 -- but only at doses thought also to inhibit 5-HT(2C) receptors--the noradrenaline (NA) reuptake inhibitor desipramine, the benzodiazepine inverse agonist FG-7142, the alpha(2)-adrenergic receptor antagonist yohimbine, the neurokinin (NK)(1) receptor antagonist L-733.060, and the NK(2) receptor antagonist SR-48968. Compounds that increased TI include the benzodiazepine agonists diazepam and alprazolam, and the alpha(2)-adrenergic receptor agonist clonidine. The selective 5-HT reuptake inhibitors citalopram, paroxetine and fluoxetine, the 5-HT(1A) receptor antagonist WAY100.635, the 5-HT(2C) receptor agonist MK-212, the 5-HT/NA reuptake inhibitor imipramine, the NA reuptake inhibitor talopram, the benzodiazepine antagonist flumazenil, the alpha(2)-adrenergic receptor antagonist idazoxan and the psychostimulant amphetamine did not have any effect. These findings indicate that the serotonergic, noradrenergic and neurokinin systems are involved in mediating or modulating TI behaviour in guinea pigs. The potential of TI as a behaviour for detecting anxiolytic-like effect may be questioned due to the contradictory effect of the benzodiazepine ligands, which may be attributed to the sedative and/or ataxic effects of the compounds. Nevertheless, there is preclinical evidence suggesting that 5-HT(1A) receptor agonists, 5-HT(2C) receptor antagonists and NK(1) and NK(2) receptor antagonists possess anxiolytic potential. Only when results of clinical investigations of the anxiolytic potential of non-benzodiazepine ligands (for example the NK receptor antagonists) are available, will it be possible to determine fully the predictive validity of the TI model.

How does ultraviolet light affect layer production, fear, and stress

Two receptor systems for corticosterone (CORT) can be distinguished in rat brain: mineralocorticoid-like or CORT receptors (CR) and glucocorticoid receptors (GR). The microdistribution and extent of occupation of each receptor population by CORT were studied. The CR system is restricted predominantly to the lateral septum and hippocampus. Within the hippocampus, the highest density occurs in the subiculum +/- CA1 cell field (144 fmol/mg protein) and the dentate gyrus (104 fmol/mg protein). Affinity of CR for CORT was very high (Kd, approximately 0.5 nM). The GR system has a more widespread distribution in the brain. The highest density for GR is in the lateral septum (195 fmol/mg protein), the dentate gyrus (133 fmol/mg protein), the nucleus tractus solitarii and central amygdala. Substantial amounts of GR are present in the paraventricular nucleus and locus coeruleus and low amounts in the raphe area and the subiculum + CA1 cell field. The affinity of GR for CORT (Kd, approximately 2.5-5 nM) was 6- to 10-fold lower than that of CR. Occupation of CR by endogenous ligand was 89.5% during morning trough levels of pituitary-adrenal activity (plasma CORT, 1.4 micrograms/100 ml). Similar levels of occupation (88.7% and 97.6%) were observed at the diurnal peak (plasma CORT, 27 micrograms/100 ml) and after 1 h of restraint stress (plasma CORT, 25 micrograms/100 ml), respectively. Furthermore, a dose of 1 microgram CORT/100 g BW, sc, resulted in 80% CORT receptor occupation, whereas GR were not occupied. For 50% occupation of GR, doses needed to be increased to 50-100 micrograms/100 g BW, and for 95% occupation, a dose of 1 mg CORT was required. The plasma CORT level at the time of half-maximal GR occupation was about 25 micrograms/100 ml, which is in the range of levels attained after stress or during the diurnal peak of pituitary-adrenal activity. Thus, CR are extensively filled (greater than 90%) with endogenous CORT under most circumstances, while GR become occupied concurrent with increasing plasma CORT concentrations due to stress or diurnal rhythm. We conclude that CORT action via CR may be involved in a tonic (permissive) influence on brain function with the septohippocampal complex as a primary target. In view of the almost complete occupation of CR by endogenous hormones, the regulation of the CORT signal via CR will, most likely, be by alterations in the number of such receptors. In contrast, CORT action via GR is involved in its feedback action on stress-activated brain mechanisms, and GR occur widely in the brain.(ABSTRACT TRUNCATED AT 400 WORDS)

This article reviews research concerning the possible relationship between tonic immobility (TI) and human reactions to sexual assault. This review includes a description of the characteristic features of TI and a discussion of the most widely accepted theoretical explanation for TI. The possibility that humans may exhibit TI is explored and conditions that might elicit TI in humans are identified. In particular, we focus on TI in the context of sexual assault, because this form of trauma often involves elements that are necessary for the induction of TI in nonhuman animals, namely, fear and perceived physical restraint. The important similarities and differences in how TI manifests in humans and nonhuman animals are highlighted, future research directions are offered, and clinical implications are suggested.

The stress physiology of extended duration tonic immobility in the juvenile lemon shark, Negaprion brevirostris (Poey 1868)

Environmental conditions during incubation and rearing can influence stress responsivity of laying hen pullets throughout their lifespan, and therefore have important implications for their welfare. In this study, a 12:12h green LED light-dark cycle during incubation and larvae provisioning as enrichment during rearing were tested as strategies to optimize early-life conditions and thereby decrease stress responsivity in ISA Brown laying hens. A combination of parameters was measured to indicate neuronal, physiological, and behavioral changes that may affect fear and stress. The proteins calbindin D28k (calbindin1), doublecortin (DCX), and neuronal nuclein protein (NeuN) were quantified after hatch as a proxy for brain plasticity. Plasma and feather corticosterone levels were measured after hatch and at the end of the rearing phase, and fearfulness was investigated through a series of behavioral tests (i.e., voluntary approach, open field, tonic immobility, and manual restraint tests). No effects of light during incubation were found on calbindin1, DCX, or NeuN. Neither of the treatments affected corticosterone levels in blood plasma and feathers. Light-incubated pullets showed less fearfulness towards humans in the voluntary approach test, but not in the other behavioral tests reported in this study. Larvae provisioning had no effect on behavior. Our study showed minor effects of light during incubation and no effects of enrichment during rearing on stress responsivity of laying hen pullets. The small effects may be explained by the enriched rearing conditions for all birds in this experiment (low stocking density, natural daylight, and 24/7 classical music). Given the promising results of lighted incubation in other studies, which were mostly performed in broiler chickens, and evidence regarding the positive effects of enrichment during rearing, the potential of these strategies to improve laying hen welfare needs to be explored further.

The seasonal glucocorticoid response of male Rufous-winged Sparrows to acute stress correlates with changes in plasma uric acid, but neither glucose nor testosterone

The genetic relationships between behavior and digestive efficiency were studied in 860 chickens from a cross between two lines divergently selected on digestive efficiency. At 2weeks of age each chick was video-recorded in the home pen to characterize general activity and feeding behavior. Tonic immobility and open-field tests were also carried out individually to evaluate emotional reactivity (i.e. the propensity to express fear responses). Digestive efficiency was measured at 3weeks. Genetic parameters of behavior traits were estimated. Birds were genotyped on 3379 SNP markers to detect QTLs. Heritabilities of behavioral traits were low, apart from tonic immobility (0.17-0.18) and maximum meal length (0.14). The genetic correlations indicated that the most efficient birds fed more frequently and were less fearful. We detected 14 QTL (9 for feeding behavior, 3 for tonic immobility, 2 for frequency of lying). Nine of them co-localized with QTL for efficiency, anatomy of the digestive tract, feed intake or microbiota composition. Four genes involved in fear reactions were identified in the QTL for tonic immobility on GGA1.

The relationship between adjunctive drinking, blood ethanol concentration and plasma corticosterone across fixed-time intervals of food delivery in two inbred mouse strains