Flueck, M. | bioRxiv Science

bioRxiv2023

An adaptable, user-friendly score sheet to monitor welfare in experimental fish

Fish are increasingly used as experimental animals across research fields. Currently, a quarter of all experimental animals used in Europe are fish. Less than 20% of these are standard model species. Welfare assessments for experimental fish are in their infancy compared to rodents. This can be attributed to the diversity of species used, the relative recency of fish as go-to model for research, and challenges to assess welfare and pain in non-vocal underwater species. The lack of guidelines and tools presents a challenge for researchers (particularly, for newcomers), for ethics committees, and for implementing refinement measures. Here, we present an adaptable, user-friendly score sheet for fish. The parameters contained in the excel tool are based on a literature review, have been validated by expert interviews, and evaluated by a fish pathologist. The tool allows to score individuals as well as groups, calculates summary scores and visualizes trends. We provide the underlying literature, give use examples and provide instructions on the adaptation and use of the score sheet. We hope that this tool will empower researchers to include welfare assessment in their routines, foster discussions on fish welfare parameters among scientists, facilitate interactions with ethics committees, and most importantly, enable the refinement of fish experiments.

animal behavior and cognition↗

bioRxiv2021

JNK activation in TA and EDL muscle is load-dependent in rats receiving identical excitation patterns

ABSTACTO_ST_ABSAimC_ST_ABSAs the excitation-contraction coupling is inseparable during voluntary exercise, the relative contribution of the mechanical and neural input is poorly understood. Herein, we use a rat in-vivo strength training setup with an electrically induced standardized excitation pattern previously shown to lead to a load-dependent increase in myonuclear number and hypertrophy, to study acute effects of load per se on molecular signalling. MethodsAnaesthetized rats were subjected to unliteral identical electrically-paced contractions of the TA and EDL muscles under a high or low load for a duration of 2, 10 or 28-minutes. Muscle soluble proteins were extracted, and abundance and specific phosphorylations of FAK, mTOR, p70S6K and JNK were measured. Effects of exercise, load, muscle and exercise duration were assessed. ResultsSpecific phosphorylation of S2448-mTOR, T421/S424-p70S6K and T183/Y185-JNK was increased after 28-minutes of exercise under the high- and low-load protocol. Elevated phosphorylation of mTOR and JNK was detectable already after 2 and 10 minutes of exercise, respectively, but greatest after 28-minutes of exercise. T183/Y185-JNK and S2448-mTOR demonstrated a load-dependent increase in phosphorylation in the exercised muscles that for mTOR depended on muscle type. The abundance of all four kinases was higher in TA compared to EDL muscle. FAK and JNK abundance was reduced after 28 minutes of exercise in both the exercised and control muscle. ConclusionThe current study shows that JNK and mTOR activation is load-driven, and together with muscle-type specific mTOR and p70S6K effects it may drive muscle-type specific exercise and load-responses.

physiology↗