Characterization of a mammalian prosencephalic functional plan

• Main Authors: Sophie eCroizier, Sandrine eChometton, Dominique eFellmann, Pierre-Yves eRisold
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2015-01-01
• Series: Frontiers in Neuroanatomy
• Subjects: Medial Forebrain Bundle; melanin concentrating hormone; lateral hypothalamic area; cell cord; pioneer tracts
• Online Access: http://journal.frontiersin.org/Journal/10.3389/fnana.2014.00161/full

Hypothalamic organizational concepts have greatly evolved as the primary hypothalamic pathways have been systematically investigated. In the present review, we describe how the hypothalamus arises from a molecularly heterogeneous region of the embryonic neural tube but is first differentiated as a primary neuronal cell cord (earliest mantle layer). This structure defines two axes that align onto two fundamental components: a longitudinal tractus postopticus/retinian component and a transverse supraoptic tract/olfactory component. We then discuss how these two axonal tracts guide the formation of all major tracts that connect the telencephalon with the hypothalamus/ventral midbrain, highlighting the existence of an early basic plan in the functional organization of the prosencephalic connectome.