Phosphoprotein Associated with Glycosphingolipid-Enriched Microdomains Differentially Modulates Src Kinase Activity in Brain Maturation

Src family kinases (SFK) control multiple processes during brain development and function. We show here that the phosphoprotein associated with glycosphigolipid-enriched microdomains (PAG)/Csk binding protein (Cbp) modulates SFK activity in the brain. The timing and localization of PAG expression overlap with Fyn and Src, both of which we find associated to PAG. We demonstrate in newborn (P1) mice that PAG negatively regulates Src family kinases (SFK). P1 Pag1-/- mouse brains show decreased recruitment of Csk into lipid rafts, reduced phosphorylation of the inhibitory tyrosines within SFKs, and an increase in SFK activity of >/ = 50%. While in brain of P1 mice, PAG and Csk are highly and ubiquitously expressed, little Csk is found in adult brain suggesting altered modes of SFK regulation. In adult brain Pag1-deficiency has no effect upon Csk-distribution or inhibitory tyrosine phosphorylation, but kinase activity is now reduced (−20–30%), pointing to the development of a compensatory mechanism that may involve PSD93. The distribution of the Csk-homologous kinase CHK is not altered. Importantly, since the activities of Fyn and Src are decreased in adult Pag1-/- mice, thus presenting the reversed phenotype of P1, this provides the first in vivo evidence for a Csk-independent positive regulatory function for PAG in the brain

A comparative meta-analysis on the relationship of faecal calcium and phosphorus excretion in mammals

To investigate the relationship between faecal calcium (Ca) and phosphorus (P) excretion in different mammalian species, a meta-analysis on digestibility data derived from the literature was conducted. Seventy-three studies on carnivores, omnivores, large and small hindgut fermenters, ruminants and hippos (a total of 21 mammalian species, precondition for inclusion dietary Ca/P ratio 1.5/1 – 3.0/1) were analysed for Ca and P digestibility. Dietary Ca/P ratios were lower than faecal Ca/P ratios in carnivores, omnivores, ruminants and hippos. In hindgut fermenters, dietary Ca/P ratios were higher than faecal Ca/P ratios, indicating higher intestinal Ca absorption in these species. In all species investigated, there was a significant positive relationship between Ca intake and faecal Ca excretion and between P intake and faecal P excretion. In the biologically relevant range, these equations predicted lower faecal Ca losses in hindgut fermenters than ruminants, for faecal P vice versa. In all species, faecal Ca and P excretion correlated significantly. In carnivores, this highly linear correlation was exceptionally strong (R² = .92). Yet, the linearity of the correlation was questionable in omnivores and ruminants. Possibly, the strong linear correlation of faecal Ca and P excretion in carnivores is due to the formation of insoluble Ca/P complexes in their relatively short and simple gastrointestinal tract. Another hypothesis is that in carnivores, Ca homeostasis relies on modifying bone turnover to a higher degree than on changes in intestinal Ca absorption. For the formation of bone matrix, a constant ratio of Ca and P absorption is of advantage

Ernährungsberatung in der Kleintierpraxis – ein Arbeitsfeld für spezialisierte Tierärzte

ZusammenfassungGegenstand und Ziel: Es wurde geprüft, wodurch die Etablierung der Ernährungsberatung in der Kleintierpraxis erschwert wird. Ferner werden Unterschiede im Problemlöseverhalten von Tierärzten bei der Ernährungsberatung dargestellt. Material und Methoden: Repräsentative Online-Befragung von 214 Tierärzten (weiblich/männlich) mittels eines standardisierten Fragebogens, Faktorenanalyse zur Typisierung der Tierärzte anhand einer Clusteranalyse. Ergebnisse: Mehr als 90% der Tierärzte waren der Ansicht, dass Fragen der Tierbesitzer zur Fütterung von Haustieren zugenommen haben, 41% der Tierärzte schätzten den Anteil ernährungsbedingter Krankheiten auf 20–30%. Gleichzeitig stimmten 70% der Aussage zu, dass die Ernährungsberatung im Praxisalltag vernachlässigt wird. Nach Angabe der Tierärzte setzen nur knapp 30% der Besitzer Ernährungsempfehlungen um. Mehr als 80% der Tierärzte nahmen an, dass Tierbesitzer falsche Angaben zur Fütterung der Tiere machen. In anderen sensiblen Punkten wie z. B. der häuslichen Situation wurden unrichtige Angaben dagegen auf unter 60% eingeschätzt. Etwa die Hälfte der Tierärzte fühlte sich bei der Ernährungsberatung nicht kompetent. Weniger als 50% liquidierten für diese Leistung. Eine Fortbildung zur Tierernährung besuchten nur 18% der Tierärzte. Die Clusteranalyse identifizierte fünf typische Verhaltensstrategien im Umgang mit der Ernährung, wobei vier davon auf einem eher geringen Stellenwert der Ernährung basierten. Einige der an Ernährungsfragen wenig interessierten Tierärzte überweisen an spezialisierte Kollegen (7,2%), andere wenden sich ratsuchend an die Futtermittelindustrie (28,2%), wieder andere behelfen sich mit kurzen kostenlosen Fütterungstipps (23,4%) und ein kleiner Teil verdrängt die Tierernährung weitgehend (13,4%). Es gibt aber auch eine Gruppe an der Tierernährung besonders interessierter Tierärzte (27,8%). Diese Gruppe war sich der Defizite bei den fachlichen und kommunikativen Kompetenzen am stärksten bewusst. Schlussfolgerung und praktische Relevanz: Für eine fundierte Ernährungsberatung in der Kleintierpraxis sind ein hoher Spezialisierungsgrad sowie praktikable Lösungen für die Anamneseerhebung und die Liquidierung notwendig.</jats:p

Guinea pig (Cavia porcellus) drinking preferences: do nipple drinkers compensate for behaviourally deficient diets?

When offered diets with hay ad libitum, rabbits (Oryctolagus cuniculus) clearly prefer open dishes over nipple drinkers, but whether this preference also applies in guinea pigs (Cavia porcellus) is unsure. We tested the drinker preference of 10 guinea pigs when offered open dishes (OD) and nipple drinkers (ND) simultaneously and measured the amount of water consumed by each animal on four different diets (grass hay 100%, or as 10% of intake on diets of fresh parsley, seed mix or pelleted complete feed, respectively) on either of the drinking systems. All animals ingested the hay portion of the combined diets first. The amount of water consumed differed significantly between individual animals. Animals drank less water on parsley than on the other diets. Nine of 10 animals clearly preferred ND when having a choice, and eight of these drank more when on ND only. The difference between the drinking systems was not consistent across all diets: on hay, similar amounts of water were drunk when on OD or ND only. Differences in water intake were reflected in urine production. Because drinking from ND in guinea pigs involves jaw movements similar to those in chewing, the results could suggest that when motivation for oral processing behaviour is not satisfied by a diet, animals may respond in using ND beyond physiological water necessity. Whereas physiological water requirements are probably better investigated with other drinking systems due to a possible overestimation when using ND, offering ND to pet guinea pigs most likely offers a form of behavioural enrichment that at the same time may increase water intake and hence act as prophylaxis against urolithiasis

Consistency in behavior: Evaluation of behavior tests in laboratory beagles.

In the present report, we analyzed the consistency in the behavior of laboratory dogs in 4 standardized tests (an encounter test with a familiar caretaker, an encounter test with an unfamiliar test person, a simulation of experimental manipulation, and a complex behavior test) that were conducted on 2 consecutive days. We further analyzed whether the dogs&rsquo; behavior in the subsequent tests could be predicted by the preceding tests. Data of 90 laboratory beagles kept in 4 research facilities were reevaluated for this purpose by using Kruskal&#39;s gamma, Spearman rank correlation, and simple linear regression. Correlations of behavior scores based on the behavior reactions of the dogs were low to moderate between the investigations. Only the test part isolation, where the dogs were left alone in an unfamiliar room, was highly correlated to the test part entering (of another unfamiliar room) in the experimental manipulation. Regarding the body language scores, there were considerably more moderate to high correlations between the respective investigations and test parts. The encounter test with the familiar caretaker had predictive power (P &lt; 0.001) regarding the encounter test with an unfamiliar test person on the next day but not with respect to the behavior in the behavior test. However, the experimental manipulation predicted the behavior in the behavior test (P &lt; 0.001). We conclude that body language is more consistent for individual dogs than are their reactions in different situations. Thus, a detailed behavior test that includes different situations and stimuli cannot be replaced by a simple encounter test in the familiar housing surroundings. In contrast, the simulation of experimental manipulation can be a better predictive tool

Behavior of laboratory beagles towards humans: Assessment in an encounter test and a simulation of experimental situations.

Because of the close emotional bonds between the man and the domesticated dog, husbandry of laboratory dogs is regarded with particular interest by the public. The relationship between laboratory dogs and the man is particularly important for animal welfare, and daily contact with caregivers and handlers should not elicit fear in dogs. The aim of this study was to investigate the behaviors of laboratory dogs toward humans. In 4 research facilities, 90 male and female 1- to 10-year-old laboratory beagles of different origins (facility bred or from other origins) were tested in an &quot;encounter test&quot; and a setting that simulated realistically general research situations. No significant differences were observed in the encounter test when the dogs were approached by a familiar caretaker or by an unfamiliar person. Nearly all of the dogs could be caught easily, and they exhibited pronounced interest in and established contacts with both persons. We simulated an experimental manipulation by placing the dogs on a treatment table in an examination room and having them restrained by a familiar caretaker; this resulted in submissive behavior and/or signs of distress in many dogs (e.g., 12% urinated when being lifted onto the examination table and most dogs showed muzzle licking on the table). Multifactorial analysis of variance revealed that, based on most of the calculated scores, the facility-bred dogs were significantly less fearful than those obtained from commercial breeders or from other research facilities. Sex differences were not observed, and younger dogs were significantly more difficult to catch. The data revealed that good relationships were established between the caretakers and the dogs in all 4 research facilities. The facility-bred dogs in particular were friendly and exhibited little fear toward both the familiar and unfamiliar persons