Maternal deprivation disrupts mitochondrial energy homeostasis in the brain of rats subjected to ketamine-induced schizophrenia

Abstract

Maternal deprivation (MD) appears to be one of the environmental factors involved in the pathophysiology of schizophrenia. A widely used animal model of the schizophrenia involves the administration of ketamine, a dissociative anesthetic, NMDA receptors noncompetitive antagonist, that induce symptoms such as schizophrenia. To clarify the molecular mechanism of schizophrenia induced by MD, we investigated alterations in energetic metabolism, oxidative stress and neurotrophic factor levels in the brain of rats following MD and/or a single administration of ketamine during adulthood. Male Wistar rats were subjected to MD for 10 days. Additionally, these animals received acute ketamine (5, 15 or 25 mg/kg by intraperitoneal route, i.p.) during adulthood, and 30 min later, they were killed and the prefrontal cortex (PFC), the hippocampus and the striatum were removed for molecular analyses. Ketamine 25 mg/kg and/or MD and Ketamine 15 and 5 mg/kg with MD decreased the creatine kinase (CK) activity in the hippocampus. The enzyme activity of succinate dehydrogenase (SDH) in the Krebs cycle had increased in the striatum following the administration of ketamine 25 mg/kg, MD per se or MD plus ketamine 5 and 15 mg/kg. MD per se or MD combined with ketamine in different doses increased the activity of mitochondrial complexes. The PFC of animals subjected to MD and administered with ketamine 5 mg/kg exhibited increased protein carbonyl content. In the hippocampus, ketamine 15 mg/kg, ketamine 25 mg/kg and MD each increased the carbonyl content. In the striatum, the TBARS levels were increased by the administration of ketamine 25 mg/kg. Finally, in the hippocampus, MD alone or in combination with ketamine reduced the Nerve Growth Factor (NGF) levels; however, the Brain-derived Neurotrophic Factor (BDNF) levels were unaltered. In the present study, we suggest that MD increased the risk of psychotic symptoms in adulthood, altering different parameters of energy and oxidative stress. Our results suggest that adverse experiences occurring early in life may sensitize specific neurocircuits to subsequent stressors, inducing vulnerability, and may help us understand the pathophysiological mechanisms involved in this disorder.

Long‐Term Effects of Maternal Deprivation on Redox Regulation in Rat Brain: Involvement of NADPH Oxidase

“…Findings of structure specific changes in the brain of MD rats in our investigations are in congruence with the findings of Zugno et al [57]. These authors have investigated the effects of MD conducted for 3 h per day during the first 10 days of life on the oxidative stress parameters in the cortex, hippocampus, and striatum of 60-day-old rats.…”

Oxidative stress, prefrontal cortex hypomyelination and cognitive symptoms in schizophrenia

“… 13 In addition, obstetric events, such as hypoxia, and environmental insults later in life, such as social stress, are associated with oxidative stress and represent risk factors for SZ. 14 , 15 , 16 , 17 , 18 , 19 , 20 …”

A Molecular Framework for Autistic Experiences: Mitochondrial Allostatic Load as A Mediator between Autism and Psychopathology

“…Importantly, many pre-clinical models for MDD are induced by ELS, and consistently implicate mitochondrial mechanisms in the subsequent development of depressive behaviors (110). For example, in vivo models for MDD have shown that mitochondrial ETC complex activity is disrupted in brain tissue following maternal deprivation, social isolation, restraint stress, mild stress, and unpredictable stress (117)(118)(119)(120)(121)(122). Moreover, several transcriptomic studies have reported significant dysregulation of mitochondrial genes involved in lipid metabolism, oxidative phosphorylation (OXPHOS) and glucose homeostasis in preclinical models for chronic and acute stress (108,(123)(124)(125).…”