title: Forebrain neuroanatomy of the neonatal and juvenile dolphin (T. truncatus and S. coeruloalba).
abstract: Knowledge of dolphin functional neuroanatomy mostly derives from post-mortem studies and non-invasive approaches (i.e., magnetic resonance imaging), due to limitations in experimentation on cetaceans. As a consequence the availability of well-preserved tissues for histology is scarce, and detailed histological analyses are referred mainly to adults. Here we studied the neonatal/juvenile brain in two species of dolphins, the bottlenose dolphin (Tursiops truncatus) and the striped dolphin (Stenella coeruleoalba), with special reference to forebrain regions. We analyzed cell density in subcortical nuclei, white/gray matter ratio, and myelination in selected regions at different anterior-posterior levels of the whole dolphin brain at different ages, to better define forebrain neuroanatomy and the developmental stage of the dolphin brain around birth. The analyses were extended to the periventricular germinal layer and the cerebellum, whose delayed genesis of the granule cell layer is a hallmark of postnatal development in the mammalian nervous system. Our results establish an atlas of the young dolphin forebrain and, on the basis of occurrence/absence of delayed neurogenic layers, confirm the stage of advanced brain maturation in these animals with respect to most terrestrial mammals.
authors.affiliation: Neuroscience Institute Cavalieri Ottolenghi, University of Turin Orbassano, Italy ; Department of Veterinary Sciences, University of Turin Torino, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Parolisi
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova Legnaro, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Peruffo
authors.affiliation: Neuroscience Institute Cavalieri Ottolenghi, University of Turin Orbassano, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Messina
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova Legnaro, Italy.
authors.forename: Mattia
authors.initials: M
authors.lastname: Panin
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova Legnaro, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Montelli
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova Legnaro, Italy.
authors.forename: Maristella
authors.initials: M
authors.lastname: Giurisato
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova Legnaro, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Cozzi
authors.affiliation: Neuroscience Institute Cavalieri Ottolenghi, University of Turin Orbassano, Italy ; Department of Veterinary Sciences, University of Turin Torino, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Bonfanti
keywords: bottlenose dolphin; cerebellum; germinative layers; lateral ventricle; postnatal brain development; striatum; striped dolphin; thalamus