Phylogenetic context of some “reference species” that can be used in behavioral neurosciences. The figure underlines the position and phylogenetic distances of a few species in relation to each other, and suggest how this information can be used to inform the selection of organisms for research. For example, while most research in the behavioral neurosciences is performed using rodents, selecting a species from an outgroup—for example, chicks or lizards—could inform researchers on evolutionary conservation of biobehavioral traits in mammals. These informations complement the usual criteria for species choice (ease of reproduction, rapid generation time, etc.) and the availability of behavioral and physiological assays.

Neuropeptides involved in anxiety disorder in clinical samples (Steckler, 2008). Peptides marked with asteriks (^*) have been investigated in goldfish (Carassius auratus) psychomotor activity, anxiety, or feeding assays. AVP, vasopressin; ANP, atrial natriuretic peptide; CCK, cholecystokinin; CRF, corticotropin-releasing factor; DYN, dynorphin; END, β-endorphin; GAD, generalized anxiety disorder; NPY, neuropeptide Y; PD, panic disorder; PTSD, post-traumatic stress disorder; SST, somatostatin.

Apparent paradox in the divergence and conservation of monaminergic systems in mammals, fish, and insects. Receptor and enzyme sequences are not conserved (including gene duplication in the case of teleost fish), and the brain nuclei containing monoaminergic neurons are differently distributed throughout the brain in mammals, fish, and insects, but functions appear to be relatively well-conserved.