Alterations in dendritic morphology of prefrontal cortical and nucleus accumbens neurons in post-pubertal rats after neonatal excitotoxic lesions of the ventral hippocampus.
Neonatal ventral hippocampal (nVH) lesions in rats result in adult onset of a number of behavioral and cognitive abnormalities analogous to those seen in schizophrenia, including hyperresponsiveness to stress and psychostimulants and deficits in working memory, sensorimotor gating and social interaction. Molecular and neurochemical alterations in the prefrontal cortex (PFC) and nucleus accumbens (NAcc) of nVH-lesioned animals suggest developmental reorganization of these structures following neonatal lesions. To determine whether nVH lesions lead to neuronal morphological changes, we investigated the effect of nVH lesion on dendritic structure and spine density of pyramidal neurons of the PFC and medium spiny neurons of the NAcc. Bilateral ibotenic acid-induced lesion of the VH was made in Sprague-Dawley pups at postnatal day 7 (P7); and at P70, neuronal morphology was quantified by modified Golgi-Cox staining. The results show that length of basilar dendrites and branching and the density of dendritic spines on layer 3 pyramidal neurons were significantly decreased in rats with nVH lesions. Medium spiny neurons from the NAcc showed a decrease in the density of dendritic spines without significant changes in dendritic length or arborization. The data, comparable to those observed in the PFC of schizophrenic patients, suggest that developmental loss of excitatory projections from the VH may lead to altered neuronal plasticity in the PFC and the NAcc that may contribute to the behavioral changes in these animals.
Flores
G
G
Laboratorio de Neuropsiquiatría, Instituto de Fisiología, Universidad Autónoma de Puebla, 14 Sur 6301, San Manuel, Puebla, Mexico CP. 72570. gflores@siu.buap.mx
Alquicer
G
G
Silva-Gómez
A B
AB
Zaldivar
G
G
Stewart
J
J
Quirion
R
R
Srivastava
L K
LK
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal; D003712:Dendrites / Q000187:drug effects*; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity*; D005260:Female; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D007051:Ibotenic Acid / Q000633:toxicity*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009474:Neurons / Q000166:cytology / Q000187:drug effects; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000473:pathology / Q000502:physiology; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000473:pathology / Q000502:physiology; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D016622:Silver Staining / Q000379:methods; D013997:Time Factors
D018690:Excitatory Amino Acid Agonists; D007051:Ibotenic Acid