ABSTRACT
BACKGROUND@#Prenatal stress can cause neurobiological and behavioral defects in offspring; environmental factors play a crucial role in regulating the development of brain and behavioral; this study was designed to test and verify whether an enriched environment can repair learning and memory impairment in offspring rats induced by prenatal stress and to explore its mechanism involving the expression of insulin-like growth factor-2 (IGF-2) and activity-regulated cytoskeletal-associated protein (Arc) in the hippocampus of the offspring.@*METHODS@#Rats were selected to establish a chronic unpredictable mild stress (CUMS) model during pregnancy. Offspring were weaned on 21st day and housed under either standard or an enriched environment. The learning and memory ability were tested using Morris water maze and Y-maze. The expression of IGF-2 and Arc mRNA and protein were respectively measured by using RT-PCR and Western blotting.@*RESULTS@#There was an elevation in the plasma corticosterone level of rat model of maternal chronic stress during pregnancy. Maternal stress's offspring exposed to an enriched environment could decrease their plasma corticosterone level and improve their weight. The offspring of maternal stress during pregnancy exhibited abnormalities in Morris water maze and Y-maze, which were improved in an enriched environment. The expression of IGF-2, Arc mRNA, and protein in offspring of maternal stress during pregnancy was boosted and some relationships existed between these parameters after being exposed enriched environment.@*CONCLUSIONS@#The learning and memory impairment in offspring of prenatal stress can be rectified by the enriched environment, the mechanism of which is related to the decreasing plasma corticosterone and increasing hippocampal IGF-2 and Arc of offspring rats following maternal chronic stress during pregnancy.
Subject(s)
Animals , Female , Male , Pregnancy , Rats , Cytoskeletal Proteins/metabolism , Gene Expression Regulation , Hippocampus/metabolism , Insulin-Like Growth Factor II/metabolism , Learning , Learning Disabilities/psychology , Memory Disorders/psychology , Nerve Tissue Proteins/metabolism , Prenatal Exposure Delayed Effects/psychology , Random Allocation , Rats, Wistar , Social Environment , Stress, Psychological/geneticsABSTRACT
Objective To investigate the neuroprotective mechanisms of Cerebroprotein Hydrolysate for Injection (Ⅰ) on vascular dementia in rats.Method The rat vascular dementia model was prepared using an improved two-vessel occlusion method,and the common carotid artery was only isolated but not blocked in sham group.Rats were randomly divided into sham group,model group,Cerebroprotein Hydrolysate for Injection (Ⅰ) groups with low,medium and high dose (5,10,20 mg/kg) and Cerebroprotein Hydrolysate Injection group (Cerebrolysin,Positive drug,10 mg/kg).The drug was administered by iv injection of rat tail vein once a day for two weeks,while the same volume of saline was administered in sham and model group.At the end of administration,the plasma was collected through abdominal aorta to separate serum,and rat cortex was isolated to prepare homogenate.The levels of nerve growth factor (NGF) and insulin-like growth factor 2 (IGF-2) in serum and level of gamma-aminobutyric acid (GABA) in cortex were detected by ELISA.Level of glutamate (Glu) in cortex of VaD rats was detected by colorimetry.Results Compared with model group,levels of NGF and IGF-2 in the serum of VaD rats and level of GABA in cortex were significantly increased,while level of Glu in cortex was significantly decreased after administration of Cerebroprotein Hydrolysate for Injection (Ⅰ).The increased IGF-2 and GABA levels by Cerebroprotein Hydrolysate for Injection (Ⅰ) were significantly higher than that of Cerebrolysin at same dose.Conclusion The mechanisms underlying the increased leaming and memory ability of VaD rats by Cerebroprotein Hydrolysate for Injection (Ⅰ),are possibly related to the increased levels of NGF and IGF-2 in body and a regulation of the balance between excitatory and inhibitory amino acid neurotransmitters.
ABSTRACT
Objective To investigate the neuroprotective mechanisms of Cerebroprotein Hydrolysate for Injection (Ⅰ) on vascular dementia in rats.Method The rat vascular dementia model was prepared using an improved two-vessel occlusion method,and the common carotid artery was only isolated but not blocked in sham group.Rats were randomly divided into sham group,model group,Cerebroprotein Hydrolysate for Injection (Ⅰ) groups with low,medium and high dose (5,10,20 mg/kg) and Cerebroprotein Hydrolysate Injection group (Cerebrolysin,Positive drug,10 mg/kg).The drug was administered by iv injection of rat tail vein once a day for two weeks,while the same volume of saline was administered in sham and model group.At the end of administration,the plasma was collected through abdominal aorta to separate serum,and rat cortex was isolated to prepare homogenate.The levels of nerve growth factor (NGF) and insulin-like growth factor 2 (IGF-2) in serum and level of gamma-aminobutyric acid (GABA) in cortex were detected by ELISA.Level of glutamate (Glu) in cortex of VaD rats was detected by colorimetry.Results Compared with model group,levels of NGF and IGF-2 in the serum of VaD rats and level of GABA in cortex were significantly increased,while level of Glu in cortex was significantly decreased after administration of Cerebroprotein Hydrolysate for Injection (Ⅰ).The increased IGF-2 and GABA levels by Cerebroprotein Hydrolysate for Injection (Ⅰ) were significantly higher than that of Cerebrolysin at same dose.Conclusion The mechanisms underlying the increased leaming and memory ability of VaD rats by Cerebroprotein Hydrolysate for Injection (Ⅰ),are possibly related to the increased levels of NGF and IGF-2 in body and a regulation of the balance between excitatory and inhibitory amino acid neurotransmitters.
ABSTRACT
Objective To explore the change of serum insulin-like growth factor-2 (IGF-2) and its relationship with clinical characteristics in patients with schizophrenia. Methods Fifty-one schizophrenic patients were recruited in the present study and 50 healthy volunteers served as controls. The serum IGF-2 level was measured using enzyme linked immunosorbent assay (ELISA). Positive and Negative Syndrome Scale (PANSS) was used to evaluate the psychotic symp?toms of patients. Trail Making Test-A (TMTA), Digit-Symbol Coding Test (DSCT), Continuous Performance Test (CPT) and Stroop Color-Word Test (SCWT) were used to evaluate the cognitive function of both groups. Results There were sig?nificant differences in the results of TMTA, DSCT, CPT and SCWT between patient and control groups. The serum levels of IGF-2 were significantly lower in patients than that in controls [(202.7±40.7) ng/mL vs. (365.9±65.5) ng/mL, P0.05). Furthermore, significant correlations were found between the serum IGF-2 level and the negative symptom sub?scale of PANSS (r=-0.397, P=0.004), CPT score (r=0.378, P=0.006), SCWT-word number (r=0.289, P=0.040), SC? WT-color number (r=0.327, P=0.019) and SCWT-word/color number (r=0.386, P=0.005) in schizophrenic patients. Con?clusion The serum IGF-2 levels of patients with schizophrenia are significantly lower than that of healthy controls, and the IGF-2 level is associated with the severity of negative symptoms and cognitive impairments in patients, indicating that serum IGF-2 might be an indicator of the severity of schizophrenia.