Low temperature-acclimation impairs cellular migration in the adult cerebral cortex of the tropical lizard, Tropidurus hispidus (Spix, 1825) (Squamata: Tropiduridae).
The effects of different temperature-acclimations on cellular proliferation and migration were studied in the cerebral cortex of the tropical lizard, Tropidurus hispidus. Lizards were divided in two groups: warm-acclimated lizards (WALs), maintained at the temperature and photoperiod conditions of their natural habitat (mean temperature 26°C; 12:12 light:dark) and the cold-acclimated lizards (CALs), maintained at the same cycle of illumination and a mean temperature of 16°C. Animals were injected with the proliferative marker 5-bromodeoxyuridine (BrdU) and euthanized fifteen or thirty days later for the immunostaining. There was no difference in the number of BrdU-positive nuclei between the experimental groups in any of the cortical layers. In CALs, the positive nuclei were found mostly close to the ependyma, whereas in WALs many positive nuclei were also found in the plexiform and cellular layers of the cortex. In CALs, BrdU-positive nuclei appeared grouped (of 2-3 nuclei), a characteristic not seen in the other group. These data suggest that temperature affects the migrating capability of the newly generated neurons in the lizard cortex, but appears not to interfere with its generation.
Departamento de Fisiologia, Universidade Federal de Sergipe, São Cristóvão-SE, Brasil. murilomarchioro@yahoo.com.br
Murilo
M
Marchioro
Hugo De Carvalho
Hde C
Pimentel
Marcia Leite
ML
Santos
Matheus Macêdo
MM
Lima
José Ronaldo
JR
Dos Santos
Xavier Ponsoda
XP
Martí
Assuncion
A
Molowny
Carlos Lopez
CL
Garcia
D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology*; D049109:Cell Proliferation; D002540:Cerebral Cortex / Q000166:cytology* / Q000378:metabolism; D003080:Cold Temperature / Q000009:adverse effects*; D000089622:Doublecortin Domain Proteins; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D008116:Lizards / Q000033:anatomy & histology / Q000502:physiology; D008297:Male; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism; D017440:Photoperiod
D000089622:Doublecortin Domain Proteins; D005904:Glial Fibrillary Acidic Protein; D008869:Microtubule-Associated Proteins; D009479:Neuropeptides; D001973:Bromodeoxyuridine