Neuroendocrinology of agonostic interaction and social signalling in Artic charr (Salvelinus alpinus) : Studies on the neuroendocrine regulation of aggressive behaviour, stress responses and skin colour

Abstract

This thesis shows that socially subordinate Arctic charr (Salvelinus alpinus) display elevated brain serotonergic (5-HT) and norepinephric activity along with a chronic activation of the hypothalamic-pituitary-interrenal (HPI) axis, including elevated plasma concentrations of á-MSH. Furthermore, subordinate fish showed an inhibition of aggressive behaviour and darker body coloration, skin darkness being positively correlated with plasma á-MSH. Fish kept on dark background, and thus being darker in body colour, were less aggressive than conspecifics interacting on white background, supporting the hypothesis that skin darkening could signal social submission. The 5-HT1A -receptor agonist 8-OH-DPAT stimulated HPI axis activity in non-stressed fish, but if administrated to stressed fish it inhibited HPI axis activity, suggesting that 5-HT1A receptors may act as both post- and pre-synaptic receptors. 8-OH-DPAT also induced skin darkening in both non-stressed and stressed fish. Stimulation of brain dopaminergic activity by L-dopa treatment counteracted the stress-induced inhibition of aggressive behaviour, and stress related effects on brain 5-HT activity and plasma levels of cortisol. In conclusion, social subordination in Arctic charr results in skin darkening and an inhibition of aggressive behaviour. Stress-induced effects, that could be mediated by elevated brain 5-HT activity, and serve as a way of signalling social position and coping with stress

Similar works

Full text

thumbnail-image

Digitala Vetenskapliga Arkivet - Academic Archive On-line

redirect
Last time updated on 25/05/2016

Having an issue?

Is data on this page outdated, violates copyrights or anything else? Report the problem now and we will take corresponding actions after reviewing your request.