Trout Brain

See here for brain labelling: http://academic.emporia.edu/sievertl/verstruc/Tbrain.htm
An excerpt taken from “Environmental effects on fish neural plasticity and cognition” by Ebbesson, L. and Braithwaite, V.
Most fishes experiencing challenging environments are able to adjust and adapt their physiology and behaviour to help them cope more effectively. Much of this flexibility is supported and influenced by cognition and neural plasticity.
The brains of teleosts, such as trout, share many of the same subdivisions seen in most vertebrates: a brainstem, the cerebellum, the mesencephalon, a pair of optic lobes, the paired cerebral hemispheres of the telencephalon (forebrain) and the associated olfactory bulbs (Northcutt, 2002).
The mismatch between the structural position of the fish amygdala and hippocampus homologues appears to be a result of different developmental processes that produce fish and mammalian brains (Salas et al., 2006). During early embryonic development, the fish brain arises through a process of eversion, where the developing brain turns outwards on itself. In mammals, however, an opposite process occurs and the brain inverts effectively pulling the two halves of the developing brain in towards each other (Salas et al., 2006; Broglio et al., 2010). In the brain of adult mammals and fishes, this results in key neural regions ending up in very different positions.
Northcutt, R. G. (2002). Understanding vertebrate brain evolution. Integrated and Comparative Biology 42, 743–756.
Salas, C., Broglio, C., Duran, E., G ´ omez, A., Oca ´ na, F. M., Jim ˜ enez-Moya, F. & Rodríguez, ´ F. (2006). Neuropsychology of learning and memory in teleost fish. Zebrafish 3, 157–171.
Broglio, C., Rodríguez, F., Gomez, A., Arias, J. L. & Salas, C. (2010). Selective involvement ´ of the goldfish lateral pallium in spatial memory. Behavioural Brain Research 210, 191–201.