Project description:Moderate caloric restriction (CR) and weight loss are beneficial for the promotion of health; however, there is controversy regarding the effects of dieting regimens on behavior. In this study, we investigated two different dieting regimens: repeated fasting and refeeding (RFR) and daily feeding of half the amount of food consumed by RFR mice (CR). Mice in both regimens were subjected to 20% reduction in food intake and transiently reduced their body weights during the first 12 days of the study. Open field, light-dark transition, elevated plus maze, and forced swimming tests indicated that CR, but not RFR, reduced anxiety- and depressive-like behaviors, with a peak on day 8. Using a mouse whole genome microarray, we analyzed gene expression in the prefrontal cortex, amygdala, and hypothalamus. In addition to the caloric restriction-responsive genes commonly modified by RFR and CR, each regimen differentially changed the expression of distinct genes in each region. The most profound change was observed in the amygdala of CR mice: 884 genes were specifically up-regulated. Ingenuity pathway analysis showed that these 884 genes significantly modified 9 canonical pathways in the amygdala. alpha-adrenergic and dopamine receptor signaling were the two top-scoring pathways. Quantitative real-time RT-PCR confirmed the up-regulation of 6 genes in these pathways. Ppp1r1b encoded Darpp-32 including dopamine receptor signaling, and the increased protein was specific for CR mice. Our results suggest that moderate CR may modify anxiety- and depressive-like behaviors and alter gene expression especially in the mouse amygdala.
Project description:Moderate caloric restriction (CR) and weight loss are beneficial for the promotion of health; however, there is controversy regarding the effects of dieting regimens on behavior. In this study, we investigated two different dieting regimens: repeated fasting and refeeding (RFR) and daily feeding of half the amount of food consumed by RFR mice (CR). Mice in both regimens were subjected to 20% reduction in food intake and transiently reduced their body weights during the first 12 days of the study. Open field, light-dark transition, elevated plus maze, and forced swimming tests indicated that CR, but not RFR, reduced anxiety- and depressive-like behaviors, with a peak on day 8. Using a mouse whole genome microarray, we analyzed gene expression in the prefrontal cortex, amygdala, and hypothalamus. In addition to the caloric restriction-responsive genes commonly modified by RFR and CR, each regimen differentially changed the expression of distinct genes in each region. The most profound change was observed in the amygdala of CR mice: 884 genes were specifically up-regulated. Ingenuity pathway analysis showed that these 884 genes significantly modified 9 canonical pathways in the amygdala. alpha-adrenergic and dopamine receptor signaling were the two top-scoring pathways. Quantitative real-time RT-PCR confirmed the up-regulation of 6 genes in these pathways. Ppp1r1b encoded Darpp-32 including dopamine receptor signaling, and the increased protein was specific for CR mice. Our results suggest that moderate CR may modify anxiety- and depressive-like behaviors and alter gene expression especially in the mouse amygdala. Experiment Overall Design: We tested three feeding regimens. One group of mice had ad libitum (AD) access to food, and was used as a control group. The repeated fasting and refeeding (RFR) group of mice were fasted on day 0 and allowed to feed ad libitum on day 1. Amounts of food consumed by the three mice on day 1 were measured. The half amount of food consumed by the RFR mice was given to three mice in another cage for two days (days 0 and 1) (CR group). The fasting followed by refeeding (RFR) and the restriction of food (CR) were repeated up to day 16. Body weights and consumed chow were measured at 20:00 every day, and then the fasting or feeding period was started. In RFR mice, fasting was started on day 0.Total RNA was prepared from the prefrontal cortex, hypothalamus, and amygdala in the mice of each group on day 8. An equal amount of RNA from 4 mice in each group was pooled and used for microarray analysis.
Project description:A group of postnatal neurodevelopmental disorders collectively referred to as MeCP2 disorders are caused by aberrations in the gene encoding methyl-CpG-binding protein 2 (MECP2). Loss of MeCP2 function causes Rett syndrome (RTT), whereas increased MeCP2 dosage causes MECP2 duplication or triplication syndromes. MeCP2 acts as a transcriptional repressor, however, the gene expression changes observed in the hypothalamus and cerebellum of MeCP2 disorder mouse models suggest that MeCP2 can also upregulate gene expression. In this study, we compared gene expression changes in the amygdalae of mice lacking MeCP2 (Mecp2-null) and mice overexpressing MeCP2 (MECP2-TG). We chose the amygdala because it is a neuroanatomical region implicated in the control of anxiety and social behavior, two prominent phenotypes in MECP2-TG mice, and hypothesized that transcriptional profiling of this particular brain region may reveal expression changes relevant to heightened anxiety-like behavior and abnormal social behavior. A total of 1,060 genes were altered in opposite directions in both MeCP2 mouse models compared with wild-type littermates, with ~60% up-regulated and ~40% down-regulated. Interestingly, we found a significant enrichment of anxiety- and/or social behavior-related genes among the differentially expressed genes. To determine whether these genes contribute to the anxiety and social behavior phenotypes in MECP2-TG mice, we performed genetic and pharmacologic studies and found that a reduction in Crh suppresses anxiety-like behavior, and a reduction in Oprm1 improves social approach behavior. These studies suggest that MeCP2 impacts molecular pathways involved in anxiety and social behavior, and provide insight into potential therapies for MeCP2 disorders. This study is published in Nature Genetics http://dx.doi.org/10.1038/ng.1066. Total amygdala RNA samples were collected from Mecp2-null male mice (n=4), MECP2-transgenic male mice (n=5), and their wild type male littermates at 6 weeks of age (n=4, n=5 for each group respectively).
Project description:Investigating the molecular basis and correlates of anxiety-related and depression-like behaviors, we generated a mouse model consisting of high (HAB), normal (NAB) and low (LAB) anxiety-related behavior mice. We utilized the elevated plus-maze for testing the genetic predisposition to anxiety-related behavior and, consequently, used this as selection criterion for the inbreeding of our animals. In depression-related tests, HAB mice display a more passive, depression-like coping strategy than LAB mice, resembling clinical comorbidity of anxiety and depression as observed in psychiatric patients. Using a microarray approach, the hypothalamic paraventricular nucleus (PVN), the basolateral (BLA) and central amygdala (CeA), the cingulate cortex (Cg) and the dentate gyrus (DG) – centers of the central nervous anxiety and fear circuitries – were investigated and screened for differences between HAB, NAB and LAB mice. Analysis was performed from four to six animals per line (HAB, NAB and LAB from generation 25, respectively) per brain region, giving a total of 78 individual arrays analyzed. The LAB mouse line is referred to as reference.
Project description:Investigating the molecular basis and correlates of anxiety-related and depression-like behaviors, we generated a mouse model consisting of high (HAB) and low (LAB) anxiety-related behavior mice. We utilized the elevated plus-maze for testing the genetic predisposition to anxiety-related behavior and, consequently, used this as selection criterion for the inbreeding of our animals. In depression-related tests, HAB mice display a more passive, depression-like coping strategy than LAB mice, resembling clinical comorbidity of anxiety and depression as observed in psychiatric patients. Using a microarray approach, the hypothalamic paraventricular nucleus (PVN), the basolateral/lateral (BLA), the medial (MeA) and central amygdala (CeA), the nucleus accumbens (NAc), the cingulate cortex (Cg) and the supraoptic nucleus (SON) – centers of the central nervous anxiety and fear circuitries – were investigated and screened for differences between HAB and LAB mice. Analysis was performed from six animals per line (HAB and LAB, respectively) pooled per brain region in ten technical replicates, thereof five with a dye-swapped design giving a total of 70 array slides analyzed. The LAB mouse line is referred to as reference.
Project description:Investigating the molecular basis and correlates of anxiety-related and depression-like behaviors, we generated a mouse model consisting of high (HAB), normal (NAB) and low (LAB) anxiety-related behavior mice. We utilized the elevated plus-maze for testing the genetic predisposition to anxiety-related behavior and, consequently, used this as selection criterion for the inbreeding of our animals. In depression-related tests, HAB mice display a more passive, depression-like coping strategy than LAB mice, resembling clinical comorbidity of anxiety and depression as observed in psychiatric patients. Using a microarray approach, the hypothalamic paraventricular nucleus (PVN), the basolateral (BLA) and central amygdala (CeA), the cingulate cortex (Cg) and the dentate gyrus (DG) – centers of the central nervous anxiety and fear circuitries – were investigated and screened for differences between HAB, NAB and LAB mice.
Project description:We show that infant trauma, as modeled by infant paired odor-shock conditioning, results in later life depressive-like behavior that can be modulated by learned infant cues (i.e., odor previously paired with shock). We have previously shown that this infant attachment odor learning paradigm results in the creation of a new artificial maternal odor that is able to control pup behavior and retain its value throughout development. Here, we assess the mechanism by which this artificial maternal odor is able to rescue depressive-like behavior and show that this anti-depressant like effect results in glucocorticoid and serotonin (5-HT) related changes in amygdala gene expression and is dependent on amygdala 5-HT. Furthermore, increasing amygdala 5-HT and blocking corticosterone (CORT) in the absence of odor mimics the adult rescue effects elicited by the artificial maternal odor, suggesting a mechanism by which odor presentation exerts its repair effects.
Project description:Investigating the molecular basis and correlates of anxiety-related and depression-like behaviors, we generated a mouse model consisting of high (HAB) and low (LAB) anxiety-related behavior mice. We utilized the elevated plus-maze for testing the genetic predisposition to anxiety-related behavior and, consequently, used this as selection criterion for the inbreeding of our animals. In depression-related tests, HAB mice display a more passive, depression-like coping strategy than LAB mice, resembling clinical comorbidity of anxiety and depression as observed in psychiatric patients. Using a microarray approach, the hypothalamic paraventricular nucleus (PVN), the basolateral/lateral (BLA), the medial (MeA) and central amygdala (CeA), the nucleus accumbens (NAc), the cingulate cortex (Cg) and the supraoptic nucleus (SON) – centers of the central nervous anxiety and fear circuitries – were investigated and screened for differences between HAB and LAB mice.
Project description:We show that infant trauma, as modeled by infant paired odor-shock conditioning, results in later life depressive-like behavior that can be modulated by learned infant cues (i.e., odor previously paired with shock). We have previously shown that this infant attachment odor learning paradigm results in the creation of a new artificial maternal odor that is able to control pup behavior and retain its value throughout development. Here, we assess the mechanism by which this artificial maternal odor is able to rescue depressive-like behavior and show that this anti-depressant like effect results in glucocorticoid and serotonin (5-HT) related changes in amygdala gene expression and is dependent on amygdala 5-HT. Furthermore, increasing amygdala 5-HT and blocking corticosterone (CORT) in the absence of odor mimics the adult rescue effects elicited by the artificial maternal odor, suggesting a mechanism by which odor presentation exerts its repair effects. There are three experimental groups: 1: pups with no infant shock and the adult forced swim test (FST)with no odor; 2. pups with infant odor-shock pairing and the adult forced swim test (FST) with no odor; 3. pups with infant odor-shock pairing and adult forced swim test with infant odor.
Project description:A group of postnatal neurodevelopmental disorders collectively referred to as MeCP2 disorders are caused by aberrations in the gene encoding methyl-CpG-binding protein 2 (MECP2). Loss of MeCP2 function causes Rett syndrome (RTT), whereas increased MeCP2 dosage causes MECP2 duplication or triplication syndromes. MeCP2 acts as a transcriptional repressor, however, the gene expression changes observed in the hypothalamus and cerebellum of MeCP2 disorder mouse models suggest that MeCP2 can also upregulate gene expression. In this study, we compared gene expression changes in the amygdalae of mice lacking MeCP2 (Mecp2-null) and mice overexpressing MeCP2 (MECP2-TG). We chose the amygdala because it is a neuroanatomical region implicated in the control of anxiety and social behavior, two prominent phenotypes in MECP2-TG mice, and hypothesized that transcriptional profiling of this particular brain region may reveal expression changes relevant to heightened anxiety-like behavior and abnormal social behavior. A total of 1,060 genes were altered in opposite directions in both MeCP2 mouse models compared with wild-type littermates, with ~60% up-regulated and ~40% down-regulated. Interestingly, we found a significant enrichment of anxiety- and/or social behavior-related genes among the differentially expressed genes. To determine whether these genes contribute to the anxiety and social behavior phenotypes in MECP2-TG mice, we performed genetic and pharmacologic studies and found that a reduction in Crh suppresses anxiety-like behavior, and a reduction in Oprm1 improves social approach behavior. These studies suggest that MeCP2 impacts molecular pathways involved in anxiety and social behavior, and provide insight into potential therapies for MeCP2 disorders. This study is published in Nature Genetics http://dx.doi.org/10.1038/ng.1066.