The effect of oral corticosterone, prolactin and prolactin deprivation on weight gain and locomotor function in neonatal rats

In order to simulate the elevated corticosteroid and prolactin levels that offspring of stressed mothers may be subjected during breast feeding, rat pups were treated daily with oral corticosterone (200ng/ml milk intake) or prolactin (140ng/ml milk intake) from the 2nd to the 151h postnatal day. To investigate the potential influence of reduced prolactin intake, the mothers were either treated with bromocriptine (2ug—12ug/rat/day) or 1% ethanol (vehicle). The rat pups were subjectedto swim tests from their 8th postnatal day to examine their neuromuscular development. Results from swim tests showed latency in development in the prolactin, corticosterone and prolactin deprived/cortieosterone administered groups, compared with the controls. There was decreased daily weight gains in the treatment groups compared to the control. This study demonstrates that increased prolactin and corticosterone and decreased prolactin combined with elevated enrticoisterone levels to which suckling neonates were exposed to, had a significant negative effect on their neuromuscular adaptive mechanism involved in the normal development of the locomotor system

Ar mfinniskor och djurjfimlika? — En idéhistorisk essä

This paper deals wilh the human altitudes lo animals and the relalions between humans and animals in a Weslem hislorical perspective. Initially, we analyse some significant quotations from the Old Tesament, in particular from lhe book ofGenesis. There are two possible inlerprelalions in the Biblical tradition in which man is a metaphysical being at a higher level than all animals: the “hard" interprelalion and the “soft" one. The hard interpretation regards man as a despot or as anabsolule monarch, who can treat animals more or less arbitrarily wilhoul any respect and compassion towards them. The soft interpretation looks at the individual as a constitulional monarch, with obligations both towards the nature and olhcrspecies. He has the power over the animals, but this power demands responsibility and man acts as custodian or steward in relation to animals. These two interpretations are still valid in the current debale, even though the latter is nearly complelely dominant among most debaters today. Thereafter we describe Aristotle’s views on these issues from the Greek lradilion, early Christian notions. for example those of St Augustin, and Medieval Christian thoughts. especially Francis of Assisi and Thomas Aquinas, Thomas Aquinas wrote about lhe three teachings that have anchored Christian reflection ever since: teachings on the instrumental value of animals. the indirect obligations of humans toward animals and the nature of animal souls.Thereafler the thoughts of the Renaissance are briefly described. This part of the text also deals wilh Descartes‘ and Hobbes” views on animals in relation to humans. The thoughts of Bentham, Kant, Schopenhauer, Wagner and Hume are alsomentioned. Finally, we discuss Singers‘ controversial and well-known book Animal Liberation, published in 1975. We disagree with his arguments and conclusions. since we find them both manipulative and unrealistic.As a conclusion we quote the Medieval mystician Sl Bernhard of Clairvaux’ thoughts: that humans combine a highly developed ralionalily with an awareness of the unavoidable death. This rationality helps us lo govern the nature, but our awareness about death forces us to create a symbolical infra slruclure we call culture, civilisation, religion, science, art and philosophy that makes it possible to survive ourselves. Thanks to this symbolic infra structure we humans change fromhighly developed animals to culture individuals. Individuals that treat other creatures with care and responsibility

Medical students’ view on the use of animals in biomedical research

The purpose of this survey was to describe medical students’ views of animals and the use of animals in biomedical research. The three explanation variables used were gender, age and year of study. A vast majority (95%) of the respondents considered that animals have rights. Possible explanations to this result could be that the term has been used by the media during a relatively long period. which has made the expression common. and the students do not consider what itphilosophically and logically infers to have rights. Younger students and female students seemed to value animals higher and had a more restricted view on animals and animal research compared to other groups. More than 95% of the respondents were positive toward the possibility to use animals for scientific purposes. There was a relationship between commitment to environmental issues and caring about animal rights. A conclusion of the present study. is that more information about laboratory animals and biomedical research should be made available to the students. as well as to the general public

Effects of dopamine D4 receptor antagonist on spontaneous alternation in rats

<p>Abstract</p> <p>Background</p> <p>The present study was a component of a series of studies scrutinising the neuroreceptor substrate of behavioural flexibility in a rat model. Spontaneous alternation paradigms model the natural tendency of rodents to spontaneously and flexibly shift between alternative spatial responses. In the study it was tested for the first time if the neurochemical substrate mediating spontaneous alternation behaviour includes the dopamine D₄receptor.</p> <p>Methods</p> <p>The acute effects of the highly selective dopamine D₄receptor antagonist L-745,870 on rats' performance in a spontaneous alternation paradigm in a T-maze were examined. The paradigm was a food-rewarded continuous trial procedure performed for 20 trials.</p> <p>Results</p> <p>The spontaneous alternation rate was not affected by the doses of the drug administered (0.02 mg/kg; 0.2 mg/kg; 2 mg/kg), but the position bias of the group receiving the highest L-745,870 dose (2 mg/kg) was significantly increased compared to the group that received the lowest dose (0.02 mg/kg). No significant effects on position bias were found compared to saline. The drug did not increase response perseveration.</p> <p>Conclusion</p> <p>The results show that the neural substrate mediating the spatial distribution of responses in the spontaneous alternation paradigm includes the D₄receptor. However, the statistically significant effect of L-745,870 on position bias was found comparing a high drug dose with a low drug dose, and not comparing the drug doses with saline. For the tested doses of L-745,870 the effect on position bias was not large enough to affect the alternation rate.</p

Induction of Strategies and Habits in Rats Through two Behavioural T-maze Paradigms

Two different behavioural paradigms in T-maze were developed with the aim to induce patterns of behavioural  persistence in rats. These new procedures were based not on traditional asymmetric reinforcement  methodology, but on a modified Krechevsky paradigm using olfactory stimuli, where we found rats  spontaneously developed patterns of behavioural persistence – or behavioural “strategies” - with less than  1% probability of these occurring by chance. Rats predominantly developed spatial position (win-stay)  strategies, but also spatial alternation (win-shift) strategies, olfactory strategies, and, to a minor degree,  olfactory alternation strategies. Spatial alternation behaviour was significantly more frequent during early  (first 40 trials) than during late testing. Position bias (spatial win-stay behaviour) increased gradually with  the number of trials and was significantly increased in late (over 120 trials) compared to early testing. In  the second paradigm, habits were induced in rats using a forced-choice procedure. After 100 forced-choice  trials of running to the same side in a T- or Y-maze, the rats showed a significant propensity for this side  when allowed to choose freely, compared to the situation in which only one forced-choice trial had been  performed. Ten forced trials were not sufficient to induce this habit. Both paradigms may be useful for modelling  aspects of human habit formation and for behavioural neuroscience experiments.

Cell mediated immune response dominates in experimental mammary gland Candida krusei infection in immunocompetent and immuno - compromised (nu/nu) mice

Experimental local mammary gland Candida krusei infection in immuno-competent and in congenic athymie nude BALB/c mice over a period of 21 days demonstrated that the immunocompetent mice readily cleared the infection whereas the infection persisted in the athymic mice. The fungal burden, however, was similar in the nude mice and in the immuno-compctcnt mice until day 18 after infection. The ratio Ofinterferony/interleukin-4 (1FN-y/IL-4) concentrations in supernatants from (ZonA stimulated splenocytcs of the infected mice indicated a predominant Th1 response to the C. krusei infection. Stimulated splenocytes of the infected immuno-competent mice synthesised significantly higher concentrations of the two eytokines than did the&nbsp; splenocytes from the infected nude mice. The present study indicates that local C. krusei infection is associated with a predominant IFN-y-Th1 response although a gradual activation of the Th2 -arm (IL-4) of the immune system may beindicated late in the course of infection

Efficacy of amphotericin B and fluconazole in the murine mycotie (Candida albicans) mastitis model

The majority of animal models in antifungal tests use systemic infection and mortality and survival of infected animals as the experimental end—point. We developed a murine model of localised eandidiasis (murine myeotic mastitis) and assessedits effectiveness through infection with Candida albicans followed by intraperitoneal administration of the antifungal drugs flunazole (FLU) and amphotericin B (AmB). Lactating BALB/cJ mice at day 5 post partum were inoculated (two glands) with a high dose of a human pathogenic C. albicans wild-type strain SC5314. Animals were treated immediately after infection with either FLU or AmB intraperitoneally for 4 days and euthanized by intracardiae exsanguination and cervical dislocation following anaesthesia with a mixture of Ketamine arid Xylazine. One infected gland was fixed in formalin and examined histopathologically and the other was homogenised for quantitative fungal cultures. There were severe changes in the untreated control animals (some animals had systemic candidiasis) compared to the treatment groups which had milder lesions. Fungal burden, determined as log [colony forming units (CFU)/g of mammary gland tissue], was similar in the untreated control group (n = 10) and FLU treated group (n = 6). However, there was significantly lower CFU/g in the mammary glands in AmB treated animals (n : 6) compared to both control and FLU treated animals (p &lt; 0.05). The results indicate that AmB is more effective in prevention of murine mycotic mastitis than FLU and that the murine mycotic mastitis model may be an attractive animal model for antifungal chemotherapy studies

Refinement and Reduction Value of Aspen Furniture and Restricted Feeding of Rats in Conventional Cages

This study evaluated the impact of aspen furniture on cardiovascular parameters, locomotor activity (LA) and faecal welfare indicators in rats. A total of 12 BN and 12 F344 male rats were group housed (n=3) in conventional cages. In this crossover study, responses of all rats to the following cage furniture items were investigated: two types of simple maze, a rectangular tube and a control with no cage furniture. In one of the two maze groups, the rats had to gnaw through wood in order to obtain food. The mean values of the LA in all groups and differences in mean arterial pressure (MAP) and heart rate of the rats housed in the various furniture item groups were compared to the values of the rats housed in control cages with no furniture, on days two, six, ten and 14 in each period (both light and dark phases). The F344 rats were generally more active than the BN rats during the dark phase, but not during the light phase. Based on the MAP results, the tube appeared to be a poor choice for F344 rats, while for BN rats all furniture items seemed beneficial, with both board types apparently superior to the tube. In general, F344 rats had higher faecal corticosterone levels than BN rats with the reverse being true for secretory IgA values. In conclusion, LA and cardiovascular parameters seemed appropriate ways to evaluate the impact of cage furniture on physiological parameters, and covered structures such as tubes do not seem to provide any enrichment value in these two rat strains