title: Radial glia in the proliferative ventricular zone of the embryonic and adult turtle, Trachemys scripta elegans.
abstract: To better understand the role of radial glial (RG) cells in the evolution of the mammalian cerebral cortex, we investigated the role of RG cells in the dorsal cortex and dorsal ventricular ridge of the turtle, Trachemys scripta elegans. Unlike mammals, the glial architecture of adult reptile consists mainly of ependymoradial glia, which share features with mammalian RG cells, and which may contribute to neurogenesis that continues throughout the lifespan of the turtle. To evaluate the morphology and proliferative capacity of ependymoradial glia (here referred to as RG cells) in the dorsal cortex of embryonic and adult turtle, we adapted the cortical electroporation technique, commonly used in rodents, to the turtle telencephalon. Here, we demonstrate the morphological and functional characteristics of RG cells in the developing turtle dorsal cortex. We show that cell division occurs both at the ventricle and away from the ventricle, that RG cells undergo division at the ventricle during neurogenic stages of development, and that mitotic Tbr2+ precursor cells, a hallmark of the mammalian SVZ, are present in the turtle cortex. In the adult turtle, we show that RG cells encompass a morphologically heterogeneous population, particularly in the subpallium where proliferation is most prevalent. One RG subtype is similar to RG cells in the developing mammalian cortex, while 2 other RG subtypes appear to be distinct from those seen in mammal. We propose that the different subtypes of RG cells in the adult turtle perform distinct functions.
authors: Department of Psychiatry; Columbia University Medical Center ; New York, NY USA.
authors: Brian K
authors: BK
authors: Clinton
authors: Neuroscience Graduate Program; University of California at Davis ; Sacramento, CA USA.
authors: Christopher L
authors: CL
authors: Cunningham
authors: Department of Neurology; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research; and Neuroscience Graduate Program; University of California at San Francisco ; San Francisco, CA USA.
authors: Arnold R
authors: AR
authors: Kriegstein
authors: Department of Psychiatry and Behavioral Sciences; University of California at Davis; Sacramento, CA USA; MIND Institute; University of California at Davis; Sacramento, CA USA.
authors: Stephen C
authors: SC
authors: Noctor
authors: MIND Institute; University of California at Davis; Sacramento, CA USA; Institute for Pediatric Regenerative Medicine; University of California at Davis / Shriners Hospitals; Sacramento, CA USA; and Medical Pathology and Laboratory Medicine; University of California at Davis; Sacramento, CA USA.
authors: Verónica
authors: V
authors: Martínez-Cerdeño
keywords: adult; development; neurogenesis; radial glia; telencephalon; turtle; ventricular zone