The physiological implications of stress and its prevention through improved use of anaesthetics, sedatives, muscle relaxants and analgesics

Stress signals are mediated through different neural pathways. Ocular (sight), vibration (side line, ear) and nociception (touch and pain). Also confinement to sub optimal environments as crowding, low oxygen, wrong salinity, high CO2 (blood pH) will acti vate neural pathways. Naturally will the physiological response intensity and duration depend on which neural pathway or combination of pathways that are stimulated as well as the duration and repetition of the stimuli. For example transport with crowding may not have an immediate effect as a sudden movement, but the longevity of the signal can be detrimental. Tissue trauma, besides a primary intense response, can cause distress for a long period. Also the phylogenetic perspective has to be included when targeting reduction of physiological stress effects as the neuroanatomically differ markedly between species as salmon, cod and halibut. Therefore to develop effective measures to prevent negative stress, both from an ethical and prod uction point of view, one need to realise that each neural pathway demands its own measure and therefore will the live situation demand combination treatments, built on: 1. expected stimuli, 2. species, 3. life stage 4. targeting correct physiological mec hanisms 5. correct handling procedures. The concept of this project is therefore to combine excellence in accepted veterinarian pharmacology procedures with excellence in fish biology/physiology at a Nordic and EU level.