Large farm animal models of human neurobehavioral and psychiatric disorders: Methodological and practical considerations

Rodents, and in particular murine models, are used in the majority of preclinical animal studies to gain insight into human behavioral dysfunctions, neurological and psychiatric disorders, and to develop therapeutics for the treatment of these disorders. However, many putative new therapeutics turn out to be insufficiently effective in clinical trials, despite their good efficacy and safety in animal models. It is of utmost importance to use appropriate animal models. The brains of gyrencephalic large animal model species, such as (mini)pigs and sheep, for example, show a greater resemblance with the human brain, and might therefore be of larger translational value than rodent models. We review practical and methodological aspects of performing research with large animal models, and discuss their advantages and disadvantages. We advocate to use the animal model that best suits the aim of a study and that best informs the researcher and to consider large animal models as an option

Pigs as model species to investigate effects of early life events on later behavioral and neurological functions

Pigs are increasingly used as animal models of early life events, both as models for humans and as models for pigs in farming. The relative similarities of young pigs to young humans in terms of brain development, physiology, diet, and gastrointestinal function make pigs a potentially powerful animal model for human neonates. In farm-kept animals, effects of management practices in early life that may affect the welfare state of the animal throughout its life are underinvestigated. Tools for testing young pigs for cognitive development include operant tests, such as the holeboard, judgement bias, discrimination, and gambling tasks. Neurological testing may prove to be extremely valuable for evaluating development in pigs. All of these tests are in varying stages of validation; concerted efforts by those involved in pig research should be undertaken to validate and use validated tests in pigs. The specific welfare issues surrounding the use of pigs as model animals are discussed

In situ spectroscopic measurements of erosion behavior of TFTR-redeposited carbon materials under high-flux plasma bombardment in PISCES-A

The chemical erosion behavior of graphite materials pre-exposed in Tokamak Fusion Test Reactor (TFTR) as the bumper limiter has been investigated spectroscopically under deuterium plasma bombardment in the PISCES-A facility. The deuterium plasma bombardment conditions are: ion bombarding energy of 300 eV; ion flux of 1.7 /times/ 10/sup 18/ ions s/sup /minus/1/ cm/sup /minus/2/; plasma density of 1.4 /times/ 10/sup 12/ cm/sup /minus/3/; electron temperature of 11 eV; and neutral pressure of 3 /times/ 10/sup /minus/4/ torr. The chemical erosion yield is measured with CD-band spectroscopy during the temperature ramp from 100 to 900/degree/C at an average rate of about 5 degrees/s. The materials used include virgin POCO AFX-5Q graphite, graphite tile pieces from the redeposition-dominated and erosion-dominated areas of the bumper limiter in TFTR. It has been found in common for these graphite materials that the chemical erosion yield maximizes at a temperature around 550/degree/C. However, graphite from the redeposited area has shown a somewhat higher maximum erosion yield and significantly steeper temperature dependence. In addition, the removability of the redeposited materials by helium plasma bombardment has been studied. The removal rate is found to be similar to the physical sputtering yield of carbon by helium. The surface morphology and surface composition has been analyzed with SEM and EMPA in parallel with these erosion behavior measurements. 38 refs., 5 figs., 1 tab

Net plasma facing materials behaviour under erosion and redeposition regimes in PISCES

Submitted to Nuclear FusionSIGLEITItal