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At least 1,639 records · Page 91Linked to original sources

PubMed2005

Behavioral effects of d-cycloserine in rats: the role of anxiety level.

It has been reported that the glutamatergic N-methyl-D-aspartate (NMDA) receptor is involved in stress responses and that anxiety is the primary response to stress. Although individual differences in anxiety levels of rats have been demonstrated by using the elevated plus-maze (PM) test, the role of NMDA receptor activity in such individuality of anxiety is not clear. Here, we examined whether low (LA) and high (HA) anxiety rats might respond differently to treatment with d-cycloserine (DCS), a partial agonist of the glycine binding site located on NMDA receptors. Male Wistar rats were screened by using the PM and divided into LA and HA subgroups. On the next day, these rats were again tested in the PM, 30 min after the treatment with DCS (5, 10, or 30 mg/kg ip). Five days later, the rats were subjected to a 2-day forced swim (FS) test, receiving the DCS treatment again 30 min before the second day session. The PM data showed that DCS had anxiogenic effects in LA but not HA rats. The immobility of LA or HA rats in the FS test was not affected by DCS. The results indicate that the behavioral effects of DCS depend on the anxiety level of rats and have task-dependent behavioral consequences, suggesting that glycine binding sites on NMDA receptors are involved in individual differences of anxiety level.

Animals↗

PubMed2006

Age-dependent measures of anxiety and cognition in male histidine decarboxylase knockout (Hdc-/-) mice.

Histidine decarboxylase deficient (Hdc(-/-)) and wild-type male mice on the C57Bl6/J background were used to determine the role of histamine in brain function. 3-5 (Y) and 12-14 (MA) month-old Hdc(-/-) mice showed hypoactivity and increased measures of anxiety in the open field, light-dark, elevated plus-maze, and elevated zero maze tests. Y Hdc(-/-) mice showed superior performance in the hidden sessions of the water maze and passive avoidance memory retention. In contrast, Y Hdc(-/-) mice were impaired in novel location recognition, spent less time searching in the target quadrant and more time searching in the outer zone of the water maze during the probe trials. These behaviors are likely due to increased measures of anxiety and are not found in MA Hdc(-/-) mice. These data support a role for histamine in anxiety and cognition and underline the importance of considering age and potential effects on measures of anxiety in the interpretation of the role of histaminergic neurotransmission in cognitive function.

Age Factors↗

PubMed2006

Relative expression of D3 dopamine receptor and alternative splice variant D3nf mRNA in high and low responders to novelty.

Studies in rodents suggest an important role for the D3 dopamine receptor in regulating locomotor responses to spatial novelty and psychostimulants. The D3 receptor alternatively spliced variant D3nf produces a non-dopamine binding protein that may alter D3 receptor localization by dimerizing with the full-length receptor. In the high responder/low responder (HR/LR) model, the locomotor response to an inescapable, novel spatial environment predicts individual differences in the locomotor and rewarding effects of psychostimulants. We hypothesized that individual differences in D3 receptor expression could contribute to individual differences in the locomotor response to novelty in the HR/LR model. To test this hypothesis, we screened rats for response to a novel spatial environment and analyzed brain tissue for mRNA levels of the D3 receptor and D3nf by real-time RT-PCR. The ratios of D3/D3nf mRNA in prefrontal cortex and substantia nigra/ventral tegmentum were significantly lower in HRs than in LRs. There were no differences in relative expression of D3/D3nf between HRs and LRs in nucleus accumbens. These data further support a role for the D3 dopamine receptor in behavioral responses to novelty and, given the established relationship between novelty and psychostimulant responses, suggest that the D3 receptor may be an important target for assessment of drug abuse vulnerability. Additionally, these findings are consistent with the hypothesis that alternative splicing may contribute to regulation of D3 dopamine receptor function.

Alternative Splicing↗

PubMed2006

Can personality traits and gender predict the response to morphine? An experimental cold pain study.

The aim of the present study was to examine the possible role of personality traits, in accordance with Cloninger's theory, and gender, in the variability of responsiveness to opioids. Specifically, it was intended to test whether or not the three personality dimensions - harm avoidance (HA), reward dependence (RD) and novelty seeking (NS) - as suggested by Cloninger, can predict inter-personal differences in responsiveness to morphine after exposure to experimental cold pain. Thirty-four healthy volunteers (15 females, 19 males) were given the cold pressor test (CPT). Pain threshold, tolerance, and magnitude (VAS) were measured before and after (six measures, 30 min apart) the administration of either 0.5 mg/kg oral morphine sulphate (n=21) or 0.33 mg/kg oral active placebo (diphenhydramine) (n=13) in a randomized, double blind design. Assessment of the three personality traits, according to Cloninger's Tridimensional Personality Questionnaire, was performed before the CPT. A high HA score (but not RD, NS, or baseline values of the three pain parameters) predicted a significantly larger pain relief following the administration of morphine sulphate (but not of the placebo). Women exhibited a larger response in response to both treatments, as indicated by a significantly increased threshold and tolerance following morphine sulphate as well as significantly increased tolerance and decreased magnitude following placebo administration. The present study confirms the existence of individual differences in response to analgesic treatment. It suggests that high HA personality trait is associated with better responsiveness to morphine treatment, and that females respond better than men to both morphine and placebo.

Adolescent↗

PubMed2005

Effect of the postsynaptic 5-HT1A receptor antagonist MM-77 on stressed mice treated with 5-HT1A receptor agents.

The pharmacological effect of the 5-HT1A receptor ligands, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), indorenate, and buspirone, alone or in combination with the antagonist MM-77, was studied in mice subjected to forced swimming. It was confirmed that this stressful factor produces an anxiolytic-like effect, which is reversed by the mentioned 5-HT1A receptor agonists. Only the 8-OH-DPAT-induced decrease of such an effect could be blocked by the postsynaptic antagonist of the 5-HT1A receptor 1-(2-methoxyphenyl)-4-[(4-succinimido)butyl]-piperazine (MM-77). Stressing by forced swimming seems to induce plastic changes in 5-HT1A receptors, which in turn modify the behavioural actions of 5-HT1A receptor agents.

5-Methoxytryptamine↗

PubMed2005

The effect of neonatal handling on adult feeding behavior is not an anxiety-like behavior.

Brief periods of handling during the neonatal period have been shown to have profound and long-lasting physiological consequences. Previous studies performed in our laboratory have demonstrated that handling the pups during the neonatal period leads to increased sweet food ingestion in adult life. The objective of this study is to verify if this effect could be explained by the enhanced anxiety levels in these animals. Litters were divided in: (1) intact; (2) handled (10 min in an incubator/day) and (3) handled + tactile stimulation (10 min/day). Procedures were performed on days 1-10 after birth. When adults, rats were tested in the elevated plus maze apparatus, light dark exploration test and open field test. They were also tested for sweet food ingestion, being injected with 2 mg/kg diazepam or vehicle 60 min before the test. Handling and handling + tactile stimulation do not alter performance in the plus maze test, but handled rats presented more crossings in the light/dark exploration test and open field (two-way ANOVA). Females also spent more % time in the open arms in the plus maze and more time in the lit compartment in the light/dark test, presenting more crossings in both tests. Both treated rats (handled and handled + tactile stimulation groups) consumed more sweet food than intact ones (two-way ANOVA). When diazepam was injected prior to the measurement of sweet food ingestion, there was no effect of the drug. We suggest that handling during the neonatal period leads to plastic alterations in the central nervous system of these animals, causing an increased ingestion of palatable food in adult life, and this alteration does not express an anxiety-like behavior.

Analysis of Variance↗

PubMed2004

A single exposure to novelty differentially affects the accumbal dopaminergic system of apomorphine-susceptible and apomorphine-unsusceptible rats.

Individual differences in responses to mild, acute stressors in laboratory animals have commonly been observed in behavioural tests and at the level of hypothalamic-pituitary-adrenal axis responses. These differences are associated with dopamine transmission in the nucleus accumbens. Although the effect of mild stressors on dopamine transmission has been studied with microdialysis, it has not been studied at the level of the catecholaminergic network in the nucleus accumbens. In this study we have used microdialysis to measure extracellular concentrations of dopamine in vivo and immunocytochemistry for the enzyme tyrosine hydroxylase to assess the effect of a single exposure to novelty on the neurochemistry of the nucleus acc umbens in apomorphine-susceptible and apomorphine-unsusceptible rats. These rats are a valid animal model for studying individual differences in responses to environmental stressors and drugs of abuse. We demonstrated that a mild stressor like novelty increased the extracellular concentration of dopamine in the nucleus accumbens in apomorphine-susceptible rats to a larger and longer-lasting degree than in apomorphine-unsusceptible rats. Furthermore we demonstrated that novelty increased the tyrosine hydroxylase-immunoreactive fibre network in the nucleus accumbens shell of apomorphine-susceptible rats, which are rats that are particularly reactive to stressors, but not in the shell of apomorphine-unsusceptible rats, which are rats that are relatively stress-resistant. In conclusion, we have shown that the accumbal dopaminergic system of apomorphine-susceptible rats is more sensitive to an environmental stressor than that of apomorphine-unsusceptible rats. Combined with the fact that these animals also differ in their sensitivity to drugs of abuse, which are known to affect the dopaminergic system, these data provide a solid basis for further studying the differences in the dopaminergic responsiveness to drugs of abuse between apomorphine-susceptible and apomorphine-unsusceptible rats.

Animals↗

PubMed2004

Behavioural, neural and cardiovascular adaptations in mice lacking the NPY Y1 receptor.

Neuropeptide Y (NPY) is primarily synthesised and released by neurones, it is co-localised with noradrenaline and is involved in the regulation of cardiovascular function. In a mouse model lacking NPY Y1 receptor (KO), the ability of NPY to potentiate noradrenaline-induced vasoconstriction is abolished during stress but normal in baseline conditions, locomotor activity and metabolic rate are lowered, blood insulin levels and glucose storage activity are increased. The present study was aimed at further characterising NPY Y1 mutants, with special emphasis on: behavioural responses to novelty seeking and open-field with objects tests, heart rate responsiveness during acute social defeat, alpha2-adrenoceptor (alpha2-ARs) function in brain areas involved in cardiovascular regulation, and cardiac structure. As compared to wild-type controls (n=9), NPY Y1 KOs (n=9) showed: reduced somatomotor activation during non-social challenges, lower heart rate in baseline conditions, larger heart rate responsiveness during social defeat, increased number of alpha2-ARs in the dorsal motor nucleus of the vagus (nX) and the locus coeruleus (LC), moderately larger volume fraction of myocardial fibrosis. The remarkable increment of alpha2-adrenoceptor density in the nX and LC allows to view KO mice behavioural and anatomo-physiological peripheral characteristics as 'adaptations' to central adrenergic rearrangement due to NPY Y1 receptor deletion.

Adaptation, Physiological↗

PubMed2004

Impaired passive avoidance learning in mice lacking central neuronal nicotinic acetylcholine receptors.

The nicotinic cholinergic system influences cognition, anxiety, locomotion, and addiction by acting upon nicotinic acetylcholine receptors (nAChRs). To date, there are 12 known neuronal mammalian nAChR subunits leading to a rich pharmacological diversity that is difficult to attribute to specific subunits. We generated alpha7-beta2 nAChR double mutant mice by breeding to investigate the effect of a minimal number of nAChRs in the CNS. These mice have been used to determine the role these receptor subunits play in a variety of behaviors. A battery of behavioral tests was used to determine the effect of the mutation in anxiety, locomotor activity, startle response, pre-pulse inhibition, motor coordination and learning and memory. Mice lacking both the alpha7 and the beta2 nAChR subunits displayed impaired learning and memory performance in a passive avoidance test and showed enhanced motor performance on the rotarod.

Analysis of Variance↗

PubMed2006

Wistar rats with high versus low rearing activity differ in radial maze performance.

Substantial work has shown that rats although identical in stock, sex, age, and housing conditions can differ considerably in terms of behavior and physiology. Such individual differences, which can be detected by specific behavioral screening tests, are rather stable, that is, they probably reflect a behavioral disposition or trait. Here, we asked whether and how such differences might affect performance in a task of spatial learning and memory, the radial maze. As in our previous work, we used the degree of rearing activity in a novel open field to assign male adult outbred Wistar rats into those with high versus low rearing activity (HRA/LRA rats). They were then tested in a plus-maze for possible differences in anxiety-related behavior. Finally, and most importantly, they were food deprived and underwent maze training using an 8-arm radial maze with four non-baited and four baited arms. One of these arms consistently contained a larger bait size than the other three. In the open field, HRA rats not only showed more rearing behavior, but also more locomotor activity than LRA rats. In the plus-maze, HRA rats again showed more locomotion, but did not differ in open arm time or percentage of open arm entries, that is, conventional measures of anxiety-related behavior. In the radial maze, HRA rats consistently needed less time to consume all pellets than LRA rats, which was due to faster locomotion on the arms and less time spent at the food pits (especially in baited arms) of HRA rats. During the initial days of training, they were also more efficient in obtaining all food pellets available. Furthermore, HRA rats visited more arms and made relatively less reference memory errors than LRA rats. This allowed them to forage food quickly, but was paralleled by more working memory errors than in LRA rats. In general, working memory errors were more frequent in the arm with the large bait size, but there were no indications that HRA and LRA rats responded differently dependent on reward size. Finally, LRA rats lost slightly more weight than HRA rats during the period of food deprivation. These results are discussed with respect to the role of cognitive and motivational mechanisms, which as subject-inherent factors can contribute substantially to inter-individual variability in the radial maze.

Analysis of Variance↗

PubMedDate not supplied

Prenatal exposure to dichlorvos: physical and behavioral effects on rat offspring.

The effects of prenatal exposure to dichlorvos (DDVP), an organophosphate (OP) pesticide, on pups' physical and neurobehavioral developments were investigated. Forty pregnant rats were treated by gavage with 8.0 mg/kg DDVP or its vehicle (1 ml/kg) from the 6th to the 15th day of pregnancy. At birth, pups were weighed, the litters culled to eight animals (four male and four female), and then observed for physical (pinna detachment, incisor eruption, eye opening, testes descent, and vaginal opening) and neurobehavioral developments (palmar grasp, surface righting, negative geotaxis, and open-field behaviors). As adults, open-field, apomorphine-induced stereotypy, and passive avoidance behaviors were also assessed. Results showed no differences between the body weight of DDVP and control-treated groups. No differences were observed on the measures of physical and neurobehavioral development. Locomotor activity of male pups at 21 days of age was decreased by DDVP exposure. Adult experimental offspring showed a decreased locomotor frequency and an increased immobility duration on open-field behavior in relation to control animals; the apomorphine-induced stereotyped behavior was decreased by the pesticide exposure as well as performance on the passive avoidance task. These data suggest that prenatal DDVP exposure was able to decrease offspring motor function (adolescence and adults) and conditioned response learning, probably by interference with the cholinergic-dopaminergic balance of activity involved with the control of motor function as well as the cholinergic system that modulates learning process.

Analysis of Variance↗

PubMed2006

Effects of prenatal chlordecone on sexually differentiated behavior in adult rats.

In rodents, exposure to estrogens during early development masculinizes the structure and function of the brain. The effects of early exposure to estrogens or estrogenic compounds can be evaluated by neurobehavioral testing after puberty. In this study, the effect of developmental exposure to the chlorinated pesticide, chlordecone (CD) on sexually differentiated behaviors in adults was investigated because CD binds to estrogen receptors and causes estrogenic effects in the reproductive tract of humans and rodents at relatively high doses. Pregnant Sprague-Dawley rats were exposed to 5 mg/kg CD by intraperitoneal injection on gestation day 16 (GD 16). Offspring were gonadectomized on postnatal day 50 (PN 50) to remove the effects of circulating hormones and were sequentially tested for sex-typic spontaneous behaviors in an open field and elevated plus maze, and for male and female mating behavior following the appropriate steroid regimen. Female rats exposed in utero to CD showed an increased ratio of inner to total crossings in the open field and significantly increased lordosis and male mounting as compared to female control rats. Male rats exposed in utero to CD showed significantly increased lordosis as compared to male control rats and no change in male mating behaviors. Permanent changes in adult behavior were consistent with both estrogenic and anti-estrogenic actions following developmental exposure to CD at the dose tested.

Analysis of Variance↗

PubMed2004

Long-lasting, selective, anxiogenic effects of feline predator stress in mice.

Lasting increases in anxiety-like behavior (ALB) are produced by brief exposure of rats to a cat [Adamec RE, Shallow T, Lasting effects on rodent anxiety of a single exposure to a cat, Physiol. Behav., 54 (1993) 101-109.]. Mice also respond defensively to natural predator stimuli. Moreover, chronic exposure of mice to rat odor has immediate anxiogenic effects in plus maze and lasting (7 days) and effects on acoustic startle. The present study examined the lasting (7 days) after effects on ALB of a brief unprotected exposure of male CFW mice to a cat. Lasting effects on ALB of exposure to the cat exposure room were also assessed. Effects on behavior were studied in the hole board and elevated plus-maze (EPM). An ethological analysis of behavior revealed that risk assessment in the EPM was increased the most in predator-stressed mice. Mice exposed to the cat exposure room showed increased risk assessment falling between controls and cat exposed mice. Behavior in the hole board was unaffected, as were most other behaviors in the plus maze. Factor analysis revealed independence of risk assessment from other measures of ALB, activity and exploration, consistent with findings in rats. Aspects of the stress experience were highly predictive of later response to the cat. Cat biting and pawing, mouse fleeing and mouse weight measured at the time of cat exposure together accounted for 71% of the variance of risk assessment in cat exposed mice. The significance of these findings for vulnerability to cat predator stress of mice and for the use of predator stress in mice as a model of aspects of posttraumatic stress disorder (PTSD) are discussed.

Animals↗

PubMed2005

Differential effects of two types of environmental novelty on activity and sleep in BALB/cJ and C57BL/6J mice.

Change in the sleeping environment can produce significant alterations in sleep. To determine how these alterations may vary with the amount of change and the relative reactivity of the sleeper, we examined the influences of environmental novelty on sleep in two mouse strains that differ in behavioral anxiety. Mice [BALB/cJ (n=7) and C57BL/6J (n=8)] were implanted for recording EEG and activity via telemetry. Following baseline data collection, activity and sleep were examined over 46 h after routine cage change, after placing a simple novel object (PVC Tee) in the home cage, and after handling controls. Mice of both strains showed immediate increases in activity and decreases in rapid eye movement sleep (REM) and non-REM (NREM) after cage change and novel object. Within strain, changes in activity and sleep were greater after cage change than after novel object. Changes in activity and sleep time were significantly correlated in each strain. Compared to C57BL/6J mice, BALB/cJ mice exhibited greater and longer duration initial reductions in sleep time, and greater increases in EEG slow wave activity power after cage change and novel object, but these changes were not followed with subsequent increases in sleep time. In contrast, C57BL/6J mice showed significantly greater subsequent increases in sleep time following the initial reductions induced by both manipulations. The results suggest that initial decreases and subsequent increases in sleep time are related to putative differences in the intensity of environmental novelty (cage change>novel object) and to previously described strain differences in anxiety (BALB/cJ>C57BL/6J).

Animals↗

PubMed2006

Behavioral phenotyping of mice lacking the K ATP channel subunit Kir6.2.

ATP-sensitive potassium (K(ATP)) channels are expressed in various tissues and cell-types where they act as so-called metabolic sensors that couple metabolic state to cellular excitability. The pore of most K(ATP) channel types is built by Kir6.2 subunits. Analysis of a general Kir6.2 knockout (KO) mouse has identified a variety of different functional roles for central and peripheral K(ATP) channels in situations of metabolic demand. However, the widespread distribution of these channels suggests that they might influence cellular physiology and animal behavior under metabolic control conditions. As a comprehensive behavioral description of Kir6.2 KO mice under physiological control conditions has not yet been carried out, we subjected Kir6.2 KO and corresponding wild-type (WT) mice to a test battery to assess emotional behavior, motor activity and coordination, species-typical behaviors and cognition. The results indicated that in these test situations Kir6.2 KO mice were less active, had impaired motor coordination, and appeared to differ from controls in their emotional reactivity. Differences between KO and WT mice were generally attenuated in test situations that resembled the home cage environment. Moreover, in their home cages KO mice were more active than WT mice. Thus, our results suggest that loss of Kir6.2-containing K(ATP) channels does affect animal behavior under metabolic control conditions, especially in novel situations. These findings assign novel functional roles to K(ATP) channels beyond those previously described. However, according to the widespread expression of K(ATP) channels, these effects are complex, being dependent on details of test apparatus, procedure and prior experience.

Analysis of Variance↗

PubMed2006

Variations in behavior, innate immunity and host resistance to B16F10 melanoma growth in mice that present social stable hierarchical ranks.

The present study analyzed the effect of social stable hierarchical dominance/submissive relationships in C57BL/6 mice on behavior, innate immunity, serum corticosterone levels and host resistance to B16F10 melanoma growth. Adult mice (90 days old) kept in pairs since weaning, were analyzed for dominant/submissive ranking in three consecutive days according to the presence or absence of fighting and/or anticipatory submissive responses. Only the pairs of mice where dominant/submissive relationships were clearly stated were employed. Results showed that submissive mice presented in relation to dominants: (1) decreased time spent in the central open-field area; (2) decreased number of entries into the open arms and decreased time spent in the exploration of the open arms of the plus maze; (3) increased time spent in exploration of the plus-maze closed arms; (4) decreased number of entries and in the time spent in the exploration of the third part of the plus-maze open arms; (5) increased number of B16F10 metastasis in the lungs; (6) decreased NK cell cytotoxicity measured in vitro in the peripheral blood and spleen; (7) decreased basal but not in S. aureus induced oxidative burst in both neutrophils and monocytes and (8) similar basal serum levels of corticosterone. The present behavioral findings show that submissive mice, within a stable social hierarchy, present anxiety like-responses a fact that would make than more prone to stressful stimuli. This condition would be responsible for the decreases presently observed on basal neutrophil oxidative burst, NK cell activity and resistance to B16F10 tumor growth. Together the obtained data show that mice that present stable hierarchical relationships display neuro-immune alterations comparable to those reported in mice under a situation of chronic social stress.

Animals↗

PubMed2005

Effects of psycho-social stress during pregnancy on neuroendocrine and behavioural parameters in lactation depend on the genetically determined stress vulnerability.

The neuroendocrine consequences of repeated exposure of the pregnant mother to relevant stressors have been studied in the offspring, but not in the mothers. As these stress effects might depend on the genetically determined stress susceptibility of the dams, here, we investigated the effects of daily exposure to psycho-social stressors (maternal defeat by an aggressive lactating resident and restraint) between pregnancy days 4 and 18 in female rats selectively and bidirectionally bred for high (HAB) or low (LAB) anxiety-related behaviour. ACTH and corticosterone secretory responses to a mild stressor were found to be low in unstressed lactating HAB and LAB dams (day 8 of lactation) indicating an intact physiological attenuation of the HPA axis at this time. Pregnancy stress significantly increased the reactivity of the hypothalamo-pituitary-adrenal (HPA) axis in lactating HAB, but not LAB rats, reflecting impaired attenuation of the HPA axis selectively in pregnancy-stressed HAB dams. The high and low anxiety phenotypes were consistent in lactation and not significantly altered by pregnancy stress, despite an elevated level of arousal in pregnancy-stressed HAB dams. In general, HAB dams showed signs of a more protective maternal behaviour compared to LAB dams: (i) in the home cage, HAB dams spent more time in direct pup contact (day 1 of lactation), (ii) during two forms of the pup retrieval test, differing in the level of challenging the dam, HAB dams retrieved the pups faster, and (iii) during the maternal defence test, they were more aggressive towards a virgin intruder compared to LAB and NAB dams. Pregnancy stress did not alter any of these behavioural measures, except an increase in the speed of pup collection in a novel environment in HAB dams and increased maternal aggression in LAB dams. The results indicate a robust behavioural phenotype of HAB and LAB dams with respect to anxiety and maternal behaviour which was found to be almost unchanged by exposure to pregnancy stress. However, the finding of differential effects of pregnancy stress on the attenuation of the reactivity of the HPA axis in lactation makes HAB and LAB rats a potential animal model for studying genetically determined differences in stress vulnerability and stress-induced maladaptation of the HPA axis post-partum.

Adaptation, Physiological↗

PubMed2005

Gender-specific effects of prenatal stress on emotional reactivity and stress physiology of goat kids.

The aims of this study were to investigate the effects of maternal stress during pregnancy on the emotional reactivity, the hypothalamo-pituitary-adrenocortical (HPA) axis, and the sympatho-adrenomedullary (SAM) system of goat offspring according to their gender, and to investigate the role of maternal cortisol in prenatal stress effects. Goats were exposed to ten transports in isolation or ten ACTH injections (0.125 IU/kg body weight) during the last third of pregnancy. Control goats remained undisturbed. No effect of repeated transport during the last third of pregnancy was found on basal cortisol concentrations of the offspring. However, an increase in phenylethanolamine N-methyl transferase activity in the adrenals was observed in prenatally stressed kids compared to control kids (P = 0.031). In the presence of novelty, prenatally stressed female kids were more active (P = 0.049) than control females; they also showed more signs of arousal (P = 0.039) and tended to explore more of their environment (P = 0.053) in reaction to a startling stimulus. On the contrary, prenatally stressed male kids tended to be less active (P = 0.051) than control male kids but showed more signs of distress (P = 0.047) in the presence of novelty. Intermediate effects were found on the emotional reactivity to novelty of kids born from dams given injections of ACTH. In conclusion, transport stress in pregnant goats affects the sympatho-adrenomedullary system and the emotional reactivity of their offspring in a gender-specific manner. Moreover, the effects of prenatal transport and ACTH injections showed some similarities but differed in some critical details.

Adrenocorticotropic Hormone↗