Project description:Purpose: Identification the biological response to fear and stress in both brain and blood is vital for investigators performing peripheral studies of psychiatric traits. The goal of this study was to determine genes responsive to fear conditioning (FC), a well-characterized rodent model of threat-exposure, in the presence or absence of prior stress history, providing insight into the physiological processes underlying traumatic memory formation and trauma-related disorders such as PTSD. Methods: RNA sequencing was performed in blood and amygdala from mice that underwent fear conditioning (FC) with and without prior immobilization stress history (Immo+FC), or untreated animals (home cage HC). Libraries were prepared using the Illumina TruSeq™ RNA kit as per manufacturer’s instructions. Libraries were normalized and 8 samples were multiplexed in each lane of the flowcell. PhiX was used as an internal control on each lane to monitor the error statistics. Cluster generation was performed on the V3 flowcell on the Illumina cBot. The clustered flowcell was then sequenced on the Illumina HiSeq1000 system employing a single-end 101 cycles run. Alignment to the mm10 UCSC Mouse Assembly was performed using STAR version 2.3 (Dobin et al, 2013); parameters were set using the annotation as a splice junction reference. Sample reads were assembled into transcript models using cufflinks (v2.1.1) which were then merged and processed with cuffdiff v2.1.1, (Trapnell et al, 2012) to produce per sample FPKM expression levels and estimate differential expression between the sample groups. Results: In the amygdala, 607 genes associated with FC vs. HC (FDR<.05). In the same tissue, 516 genes showed different expression in response of immobilization (Immo+FC) compared to the FC group (FDR<.05). In the blood of the same animals, 468 genes had distinct changes in expression (Immo+FC vs FC; FDR<.05) and were enriched for biological processes such as inflammation and cytokine signaling. Conclusions: This study identified genes and pathways that respond to threat in the amygdala and blood of animals with and without a prior stress history. Future studies will be needed to examine the necessity, function and relevance of these regulated genes in human clinical stress and trauma-related disorders including.
Project description:Explore DNA methylation in focal amygdala stimulation model of epilepsy and its relationship to gene expression. Examination of expression changes in stimulated rats compared to sham operated animals in focal amygdala stimulation model of epilpesy.
Project description:Explore DNA methylation in focal amygdala stimulation model of epilepsy and its relationship to gene expression. Examination of methylation changes in stimulated rats compared to sham operated animals in focal amygdala stimulation model of epilepsy.
Project description:Delineating the molecular basis of individual differences in the stress response is critical to understanding the pathophysiology and treatment of posttraumatic stress disorder (PTSD). In this study, 7 d after predator-scent-stress (PSS) exposure, male and female rats were classified into vulnerable (i.e., M-bM-^@M-^\PTSD-likeM-bM-^@M-^]) and resilient (i.e.,minimally affected) phenotypes on the basis of their performance on a variety of behavioral measures. Genome-wide expression profiling in blood and two limbic brain regions (amygdala and hippocampus), followed by quantitative PCR validation, was performed in these two groups of animals, as well as in an unexposed control group. Differentially expressed genes were identified in blood and brain associated with PSS-exposure and with distinct behavioral profiles postexposure. There was a small but significant between-tissue overlap (4M-bM-^@M-^S21%) for the genes associated with exposure-related individual differences, indicating convergent gene expression in both sexes. To uncover convergent signaling pathways across tissue and sex, upstream activated/deactivated transcription factorswere first predicted for each tissue and then the respective pathways were identified. Glucocorticoid receptor (GR) signaling was the only convergent pathway associatedwith individual differences when using the most stringent statistical threshold. Total RNA obtained from amygdala of female rats exposed to predator-scent-stress and showing extreme (n=5 males and n=5 females) or minimal (n=5 males and n=5 females) behavioral response compared to unexposed to stress and behaviorally tested controls (n=5 males and n=5 females).
Project description:Genes that establish the circadian clock have differential expression with respect to solar time in central and peripheral tissues. Here, we find circadian-time-induced differential expression in a large number of genes not associated with circadian rhythms in two brain regions lacking overt circadian function: the dorsal vagal complex (DVC) and the central nucleus of the amygdala (CeA). These regions primarily engage in autonomic, homeostatic, and emotional regulation. However, we find striking diurnal shifts in gene expression in these regions of male Sprague Dawley rats with no obvious patterns that could be attributed to function or region. These findings have implications for the design of gene expression studies as well as for the potential effects of xenobiotics on these regions that regulate autonomic and emotional states. Micropunches of dorsal vagal complex (DVC) and central nucleus of the amygdala (CeA) were collected from male, Sprague Dawley rats at three different times of the day. Animals were not experimentally different in any way except for the time of sacrifice and collction. Gene expression of 145 genes were measured with Fluidigm's Biomark 96.96 platform.
Project description:The amygdala or amygdala-like structure in the brain are found in all vertebrates, and plays a critical role for emotional processing. But the cellular architecture of amygdala and how they evolved are still elusive. Here, we generated single-nucleus RNA-sequencing data for more than 200,000 cells in human, macaque, mouse and chicken amygdala. Abundant neuronal cell types derived from different subnuclei of amygdala were identified in all datasets. Cross-species analyses revealed GABAergic neurons and GABAergic neuron-enriched subnuclei of amygdala were well-conserved in cellular composition and marker gene expression, whereas glutamatergic neuron-enriched subnuclei were relatively divergent. Furthermore, we discovered that LAMP5+ interneurons were much more numerous in primates, while DRD2+ GABAergic neurons, LAMP5+ and SATB2+ glutamatergic neurons were predominant in the human central amygdalar nucleus (CEA) and basolateral amygdala complex (BLA), respectively. In addition, we also identified GABAergic neuron-enriched subnuclei of amygdala in the chicken. Altogether, our study highlight extremely cell-type diversity in the amygdala across species and their species-specifc adaptations.