The long-term effects of maternal deprivation depend on the genetic background

The neurodevelopmental hypothesis of schizophrenia has led to a series of n ew animal models in which the long term consequences of early manipulations are investigated. We have recently shown that a single 24-hr period of mat ernal deprivation (at postnatal day (pnd) 9) increases apomorphine suscepti bility and decreases prepulse inhibition in Wistar rats, viz. phenomena als o seen in schizophrenic patients. In the present paper, we investigated whe ther the effects of maternal deprivation were dependent on a specific genet ic background, by using different rat strains (Fischer 344 and Lewis) that differ in the Hypothalamus-Pituitary-Adrenal axis and in dopaminergic sensi tivity. The data show that in Wistar rats, basal startle amplitude was not affected by maternal deprivation, but prepulse inhibition was reduced, and apomorphine susceptibility enhanced. In Fischer 344 rats on the other hand, neither basal startle amplitude, nor prepulse inhibition were affected, bu t apomorphine susceptibility was reduced. In Lewis rats, maternal deprivati on significantly reduced basal startle amplitude, but did not affect prepul se inhibition or apomorphine susceptibility. The differential response to m aternal deprivation can best be explained by differences in baseline dopami ne sensitivity between the rat strains. Since a reduced prepulse inhibition and an enhanced susceptibility to apomorphine is also seen in schizophreni c patients, the data indicate that maternally deprived Wistar rats may repr esent an interesting developmental model for (aspects of) schizophrenia. [N europsychopharmacology 23:99-106, 2000] (C) 2000 American College of Neurop sychopharmacology. Published by Elsevier Science Inc. All rights reserved.