Dendritic and spine alterations in areas 9 and 17 in schizophrenia and Huntington chorea and the role of neuroleptic exposure

Abstract

Recent morphological studies in schizophrenia suggest atrophic changes in the neuropil of the prefrontal cortex. Most recently, we showed a schizophrenia-associated decrease in MAP2 in schizophrenia, which we believed is not due to neuroleptic exposure. MAP2 is a very important protein in the assembly of micro-tubule in neurons; therefore, it plays a major role in neuronal processes like dendrites, spines and synapses. Additionally, recent studies from our lab showed decreases in dendrites in area 32 and area 9. In this study we examined the dendrites and spines in area 9 and 17 to determine if neuroleptic drugs play a role. Huntington’s patients take neuroleptics similar to schizophrenics; therefore, by comparing the two groups to controls we can determine if neuroleptics play a role in the deficits reported in schizophrenia. Our results showed a significant decrease in both basal dendrites and spines for both layers III and V in area 9 in schizophrenia compared to controls. The Huntington’s brains, on the other hand, showed no significant difference compared to controls. In area 17, there was also no significant difference when comparing the three groups. The data suggest that neuroleptic drugs may not be responsible for the changes observed in schizophrenia.