Exploring the Dendritic Spine Pathology in a Schizophrenia-related Neurodevelopmental Animal Model

Abstract

Schizophrenia is a neurodevelopmental disorder identified by psychotic episodes, as well as cognitive deficits. There are reports of multiple alterations in the brain in schizophrenia, such as fewer dendritic spines with shape abnormalities in cortical and subcortical areas. A correlation has been established between shape and function in dendritic spines; and as the main site of excitatory synapses, the dendritic spine pathology represents a potential target for novel therapeutic tools in schizophrenia. Neonatal ventral hippocampus lesion (nVHL) in the rat has been extensively used to examine some of the pathophysiological mechanisms of schizophrenia since it mimics several behaviors, as well as abnormalities in morphological corticolimbic neurons. Thus, in this report, we determined the effects of the nVHL on locomotor behavior and memory in postpubertal rats. Also, we explored the density and the dynamics of the dendritic spines in the pyramidal neurons of layers 3 and 5 of the prefrontal cortex (PFC) and basolateral amygdala (BLA), and also in the nucleus accumbens (NAcc) medium spiny neurons (MSN). We found that nVHL rats have exhibited both hyperlocomotion and memory deficits. nVHL also reduced the number of dendritic spines and decreased the proportion of mature spines in these neurons. In conclusion, nVHL triggers behavioral abnormalities in postpubertal rats that can be associated not only with the lack of dendritic spines but also with distortion of these structures in corticolimbic neurons. Hence, the nVHL can be useful to explore the mechanisms of the dendritic spine pathology and its implications for schizophrenia.

Keywords: basolateral amygdala; dendritic spines; learning and memory; neonatal ventral hippocampus lesion; nucleus accumbens; prefrontal cortex.