[MARMAM] MRI atlas of the California sea lion brain

emontie at marine.usf.edu emontie at marine.usf.edu
Tue Oct 13 23:35:17 PDT 2009

Dear Colleagues,

We would like to draw your attention to the following paper featured on
the front cover of this month's issue of The Anatomical Record. This paper
will serve as a foundation for a series of MRI studies investigating the
effects of pollutants and domoic acid on central nervous system damage in
wild California sea lions. Please contact me if you would like a pdf copy
of this manuscript.

Montie, E.W., Pussini, N., Schneider, G.E., Battey, T.W.K., Dennison, S.,
Barakos, J., Gulland, F., 2009. Neuroanatomy and volumes of brain
structures of a live California sea lion (Zalophus californianus) from
magnetic resonance images. The Anatomical Record 292, 1523-1547.

The California sea lion (Zalophus californianus) has been a focal point
for sensory, communication, cognition, and neurological disease studies in
marine mammals. However, as a scientific community, we lack a noninvasive
approach to investigate the anatomy and size of brain structures in this
species and other free-ranging, live marine mammals. In this article, we
provide the first anatomically labeled, magnetic resonance imaging based
atlas derived from a live marine mammal, the California sea lion. The
brain of the California seal lion contained more secondary gyri and sulci
than the brains of terrestrial carnivores. The olfactory bulb was present
but small. The hippocampus of the California sea lion was found mostly in
the ventral position with very little extension dorsally, quite unlike the
canids and the mustelids, in which the hippocampus is present in the
ventral position but extends dorsally above the thalamus. In contrast to
the canids and the mustelids, the pineal gland of the California sea lion
was strikingly large. In addition, we report three-dimensional
reconstructions and volumes of cerebrospinal fluid, cerebral ventricles,
total white matter (WM), total gray matter (GM), cerebral hemispheres (WM
and GM), cerebellum and brainstem combined (WM and GM), and hippocampal
structures all derived from magnetic resonance images. These measurements
are the first to be determined for any pinniped species. In California sea
lions, this approach can be used not only to relate cognitive and sensory
capabilities to brain size but also to investigate the neurological
effects of exposure to neurotoxins such as domoic acid.

Best Regards,
Eric Montie

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