Attenuated stress responsiveness in an animal model for neurodevelopmental psychopathological disorders

Day 7 amygdala-lesioned (D7 AMX) rats have been proposed as a model for neurodevelopmental psychopathological disorders such as schizophrenia. Patients with schizophrenia are sensitive to stress and show an impaired hypothalamic-pituitary-adrenal response to certain stressful stimuli. Therefore, we investigated neuroendocrine and behavioral stress responses in the D7 AMX lesion model. Plasma concentrations of ACTH, corticosterone, and catecholamines were measured in response to foot shock and novelty in D7 and D21 lesioned (AMX) and non-lesioned (SHAM) animals. Behavior was recorded and analyzed afterwards. D7 AMX rats, unlike other rats, had a reduced ACTH response to foot shock and showed less active behavior in response to novelty. Neurodevelopmental dysfunction of target structures of the amygdala is associated with disturbed endocrine and behavioral responses to stress. These data accord with the notion that the D7 amygdala-lesioned rat can function as a neurodevelopmental model with relevance to schizophrenia.