Hello MarMam community, We are pleased to announce our new publication on killer whale neuroanatomy in *Brain Structure and Function*:
*Wright A, Scadeng M, Stec D, Dubowitz R, Ridgway S, St. Leger J. 2016. Neuroanatomy of the killer whale (Orcinus orca): a magnetic resonance imaging investigation of structure with insights on function and evolution. Brain Struct Funct. 1–20.* *Abstract:* The evolutionary process of adaptation to an obligatory aquatic existence dramatically modified cetacean brain structure and function. The brain of the killer whale (*Orcinus orca*) may be the largest of all taxa supporting a panoply of cognitive, sensory, and sensorimotor abilities. Despite this, examination of the *O. orca* brain has been limited in scope resulting in significant deficits in knowledge concerning its structure and function. The present study aims to describe the neural organization and potential function of the *O. orca* brain while linking these traits to potential evolutionary drivers. Magnetic resonance imaging was used for volumetric analysis and three-dimensional reconstruction of an in situ postmortem *O. orca* brain. Measurements were determined for cortical gray and cerebral white matter, subcortical nuclei, cerebellar gray and white matter, corpus callosum, hippocampi, superior and inferior colliculi, and neuroendocrine structures. With cerebral volume comprising 81.51 % of the total brain volume, this *O. orca* brain is one of the most corticalized mammalian brains studied to date. *O. orca* and other delphinoid cetaceans exhibit isometric scaling of cerebral white matter with increasing brain size, a trait that violates an otherwise evolutionarily conserved cerebral scaling law. Using comparative neurobiology, it is argued that the divergent cerebral morphology of delphinoid cetaceans compared to other mammalian taxa may have evolved in response to the sensorimotor demands of the aquatic environment. Furthermore, selective pressures associated with the evolution of echolocation and unihemispheric sleep are implicated in substructure morphology and function. This neuroanatomical dataset, heretofore absent from the literature, provides important quantitative data to test hypotheses regarding brain structure, function, and evolution within Cetacea and across Mammalia. The publication is available online ( http://link.springer.com/article/10.1007/s00429-016-1225-x) or by request ( [email protected] *or* [email protected]) Kind regards, Alexandra Wright ------------------------------------------------ *Alexandra Wright*, PhD candidate Center for Marine Biotechnology & Biomedicine Scripps Institution of Oceanography, UCSD [email protected] or [email protected]
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