The Journal of Neuroscience, October 15, 2002, 22(20):9070-9077
Delayed Mesolimbic System Alteration in a Developmental Animal
Model of Schizophrenia
Yukiori
Goto and
Patricio
O'Donnell
Center for Neuropharmacology and Neuroscience, Albany Medical
College, Albany, New York 12208
Pharmacological and imaging studies indicate that the prefrontal
cortex and nucleus accumbens and their dopamine innervation are central
elements of the pathophysiology of schizophrenia. Although symptoms
typically appear in young adults, a developmental component has been
suggested, primarily in the hippocampus. A neonatal hippocampal lesion
in rats and monkeys produces changes resembling schizophrenia symptoms
only after the animals reach adulthood, indicating that this procedure
could be used as a developmental animal model of this disorder. Here,
we explored whether the dopamine projection to the nucleus accumbens
becomes functionally altered in these animals. In vivo
intracellular recordings revealed abnormal responses in accumbens
neurons to activation of their dopamine afferents in adult but not
prepubertal animals with a neonatal lesion. This alteration was absent
after antipsychotic drug treatment. These results indicate that
neonatal hippocampal damage can result in delayed functional deficits
in the mesolimbic system, providing a link between the developmental
hippocampal deficit and altered dopamine systems postulated to occur in schizophrenia.
Key words:
nucleus accumbens; schizophrenia; animal model; hippocampus; dopamine; electrophysiology; antipsychotic
Copyright © 2002 Society for Neuroscience 0270-6474/02/22209070-08$05.00/0