Clinical neuroscienceAlterations in dendritic morphology of prefrontal cortical and nucleus accumbens neurons in post-pubertal rats after neonatal excitotoxic lesions of the ventral hippocampus
Section snippets
Neonatal lesions
Pregnant Sprague-Dawley rats were obtained at gestational days 14–17 from our animal facility (University of Puebla, Puebla, Mexico). Animals were individually housed in a temperature- and humidity-controlled environment on a 12-h light/dark cycle with free access to food and water. All animal procedures were in strict accordance with the guidelines of the Mexican Council for Animal Care and the Canadian Council for Animal Care and were approved by the Universidad Autónoma de Puebla Animal Care
Verification of the lesion
Animals with neonatal ibotenic acid injections showed bilateral neural loss and atrophy of the ventral hippocampal formation, as reported previously (Flores et al 1996, Brake et al 1999). A schematic representation of the extent of the lesion is shown in Fig. 1. Cavities resulting from the lesion were also frequently seen. In all lesioned animals used in the study, the dorsal-anterior portion of the hippocampal formation was spared.
Locomotor activity
The effect of nVH lesion on spontaneous locomotor activity of
Discussion
The major finding of this study is that the basilar dendrites of the prefrontal cortical pyramidal neurons from post-pubertal nVH-lesioned animals show morphological changes in the form of reduced length and arborization as well as decreased density of the dendritic spines. In addition, medium spiny neurons of the NAcc in the same animals show reductions in dendritic spine density but without significant alterations in dendritic length and branching. These changes are associated with increased
Acknowledgments
This work was supported by CONACYT No. 60446-M and VIEP-BUAP No. i.v. 34–04/SAL/G, Mexico and CIHR, Canada. We are grateful to Dr. Carlos Escamilla for his help in animal care. A.B.S. and G.A. are recipients of studentships from Puebla University. G.F. is a member of the Researcher National System of Mexico. L.K.S. is Chercheur National of the FRSQ.
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