These hormones are very imp in fish (catecholamines) Play a much more imp role in fish, especially during hypoxia. Dopamine is missing in people with parkinsons disease. Dopa is converted to dopamine, dopamine is the first catecholamine we see functioning as a nt. Ne can function as a hormone or neurotransmitter. Epinephrine is only a hormone, not a nt. These hormones are part of the stress response. The adrenal medulla is the core of the adrenal gland. As you get to other organisms, the adrenal gland is less discrete. Outer core consists of cells that synthesise and release steroid hormones. Reptiles and amphibians have adrenal glands, but no delineation bw medulla and cortex bc the cells in them can be in both places, mixed. In fish theres no difference in the adrenal gland locations. Adrenal gland secretes stress hormones like cortisol, under command of acth and that is undercontrol by crh which comes from hypothalamus.