Evidence for a decrease in basilar dendrites of pyramidal cells in schizophrenic medial prefrontal cortex

A variety of lines of converging evidence implicates the prefrontal cortex (PFC) in schizophrenia. Previous neuroanatomical studies have shown schizophrenia-associated changes in neuron density, soma size and spine number. We recently demonstrated a schizophrenia-associated decrease in microtubule-associated protein 2 (MAP2) immunostaining in laminae III and V of medial prefrontal area 32 and interpreted that finding as suggestive of a loss of dendritic material. We now present data from medial prefrontal area 32 of 11 schizophrenics and 11 comparison subjects. In Golgi-stained material, we describe a significant decrease in the number of both primary (29%) and secondary (46%) basilar dendrites on pyramidal neurons in layer V. Similarly, in layer III there was also a decrease in both primary (17%) and secondary (15%) basilar dendrites. These findings suggest a decrease in synaptic surface area which could lead to aberrant information processing.