Environmental control of smolt brain development

High quality salmon smolts are essential for aquaculture, enhancement programmes and wild populations. Intensification of aquaculture smolt production and changes in natural habitats can cause sub-optimal environmental conditins, which may result in poor smolt quality. The salmon brain as the integrator of environmental information, plays a focal role in the adaptation to environmental stress and is also especially vulnerable to such conditions, redying this informaiton to the rest of the body mainly thor ugh the endocrine system. out research has recently shown that smoltification includes major structural and chemical reoganisations of neural systems controlling smoltification-related endocrine, physiological and behavioural changes. Brain development ca n, potentially, be disrupted if 1) stimulation is never received (eg. photoperiod dependent) 2) improper or inadequate connections are formed (eg. thyroid hormone dependent), 3) altered cell function or untimely neural degeneration oc curs (eg. chemical disruptor dependent, such as aluminium) or 4) inadequate environmental stimuli are received (eg. lack of salinity exposure). The proposed project seeks to determine to what extent environmental conditions alter smolt brain development c ould ultimately lead to improved smolt production, and add to our understanding of development in general.