Project description:A parafacial region of the medulla called the retrotrapezoid nucleus (RTN) is an important respiratory control center. A group of glutamatergic neurons in this region function as respiratory chemoreceptors by regulating breathing in response to changes in tissue CO2/H+. Cellular mechanisms underlying this function involve H+-inhibition of TASK2 channels and -activation of GPR4 receptors. Evidence also suggests the RTN and greater parafacial region functions as a CO2/H+ sensing network where CO2/H+-activated and -inhibited neurons talk to each other through excitatory and inhibitory interactions. However, contributions of parafacial inhibitory neurons to control of breathing are unknown, and synaptic properties of RTN chemorecpetors have not been characterized. Here, we show the ventral parafacial region contains parvalbumin (Pvalb), cholecystokinin (CCK), neuron-derived neurotrophic factor (Ndnf) and somatostatin (SST) subtypes of interneurons including a subset strongly inhibited by CO2/H+. We also show that chemosensitive RTN neurons receive tonic inhibitory input under control conditions that is withdrawn in a CO2/H+-dependent manner, and chemogenetic inhibition of ventral parafacial inhibitory neurons increases baseline respiratory activity. These results suggest ventral parafacial inhibitory neurons are important determinants of respiratory activity under baseline conditions when the respiratory system is most prone to failure.
Project description:Sex differences in behaviors relevant to nicotine addiction have been observed in rodent models and human subjects. Behavioral, imaging and epidemiological studies also suggest underlying sex differences in mesolimbic dopamine signaling pathways. In this study we evaluated the proteome in the ventral tegmental area (VTA) and nucleus accumbens (NAc) shell in male and female mice. Experimental groups included two mouse strains (C3H/HeJ and C57BL/6J) at baseline, a sub-chronic, rewarding regimen of nicotine in C3H/HeJ mice, and chronic nicotine administration and withdrawal in C57BL/6J mice. Isobaric labeling with a TMT 10-plex system, sample fractionation, and tandem mass spectrometry were used to quantify changes in protein abundance. Similar or greater numbers of differentially regulated proteins were found between sexes at baseline in C3H/HeJ or C57BL/6J mice than within sexes following their respective regimen of nicotine administration. Despite differences by sex, strain, and nicotine exposure parameters, glial fibrillary acidic protein (GFAP) and dopamine and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32, Ppp1r1b) were repeatedly identified as significantly altered proteins, especially in the VTA. Further, network analyses showed sex- and nicotine-dependent regulation of a number of signaling pathways, including dopaminergic signaling. Sub-chronic nicotine exposure in female mice increased proteins related to dopaminergic signaling in the NAc shell but decreased them in the VTA, whereas the opposite pattern was observed in male mice. In contrast, dopaminergic signaling pathways were similarly upregulated in both male and female VTA after chronic nicotine and withdrawal. Overall, this study identifies significant sex differences in the proteome of the mesolimbic system, at baseline and after nicotine reward or withdrawal, which may help explain differential trajectories and susceptibility to nicotine addiction in males and females.
Project description:Salivary proteins of mouth breathing children were compared with paired nose breathing children using label-free quantification (LFQ). The differentially expressed proteins were screened (fold-change 1.5, p value<0.05).
Project description:Pitt-Hopkins syndrome (PTHS) is a rare autism spectrum-like disorder characterized by intellectual disability, developmental delays and breathing problems involving episodes of hyperventilation followed by apnea. PTHS is caused by functional haploinsufficiency of the gene encoding transcription factor 4 (Tcf4). Despite the severity of this disease, virtually nothing is known regarding mechanisms contributing to PTHS behavioral abnormalities, and candidate therapeutic targets are lacking. Here, we show that a Tcf4 truncation (Tcf4tr/+) mouse model of PTHS recapitulates respiratory phenotypes observed in PTHS patients. The basis of this behavior deficit involves selective loss of putative expiratory parafacial neurons and compromised function of neurons in the retrotrapezoid nucleus that regulate breathing in response to tissue CO2/H+. We also show that central Nav1.8 channels can be targeted pharmacologically to improve respiratory function at the cellular and behavioral levels in Tcf4tr/+ mice, thus establishing Nav1.8 as a high priority target with therapeutic potential in PTHS.
Project description:Muscle biopsy samples were obtained from two groups of male subjects prior to endurance training. The samples were used to predict training responses. Baseline gene expression involving 30 probe sets was able to classify subjects into high and low responders.
Project description:Muscle biopsy samples were obtained from two groups of male subjects prior to endurance training. The samples were used to predict training responses. Baseline gene expression involving 30 probe sets was able to classify subjects into high and low responders. Resting skeletal muscle sample after an overnight fast.
Project description:Walking catfish (Clarias macrocephalus) and channel catfish (Ictalurus punctatus) are freshwater fish species of the Siluriformes order. C. macrocephalus has both gills and modified gill structures serving as an air breathing organ (ABO) which allows them aerial breathing (AB), while I. punctatus does not possess an air-breathing organ (ABO), and thus cannot breathe in air. These two species provide an excellent model for studying the molecular basis of accessory air-breathing organ development in teleost fish. In this study, seven development stages in C. macrocephalus were selected for RNA-seq analysis to compare with channel catfish as the time when air breathing organ developed and became functional. Through comparative genetic contents analysis, 1,458 genes were identified to be present in C. macrocephalus, but absent from I. punctatus. Gene expression analysis and protein-protein intersection (PPI) analysis were performed, 26 genes were selected in C. macrocephalus, including mb, ngb, hbae genes, which are mainly associated with oxygen carrier activity, oxygen binding and heme binding activities. Our work provides a large data resource for exploring the genomic basis of air breathing function in C. macrocephalus and offers an insight into the adaption of aquatic organisms to hypoxia and high ammonia environment.
Project description:Purpose: The goal of this study was to characterize molecular stress responses on transcriptional level in dorsal and ventral hippocampus separately. Methods: mRNA profiles of whole, dorsal and ventral hippocampus of mice 45min after first exposure to different acute stressors. The stressors were novelty (6min novel environment), restraint (30min immobilization), or cold swim (6min in 18 degree Celcius water). 5 mice were used per condition, using Illumina HiSeq4000. The sequence reads that passed quality filters were mapped with STAR, counted with RSEM and differential gene expression was calculated using the bioconducter package edgeR. Results: With our workflow, we identified 13902 genes per sample. Approximately 20% of the genes were differentially expressed between dorsal and ventral hippocampus at baseline, with a log2 fold change >±0.3 and p value <0.005. Approximately 100 genes are differentially expressed upon stress treatment in the whole hippocampus. If ventral and dorsal hippocampus were analyzed separately, numbers increased to 150 and 250 respectively. Stress-responsive genes vary between dorsal and ventral hippocampus, and also vary between different stressors. Further analysis identified a functional epigenetic gene cluster specific for the stress response in the ventral hippocampus. Conclusions: Our study represents the first RNA-seq analysis of dorsal and ventral hippocampus after different acute stress exposures.
Project description:The hippocampus - one of the most studied brain regions – is a key target of the stress response and vulnerable to the detrimental effects of stress. Although its intrinsic organization is highly conserved throughout its long dorsal-ventral axis, the dorsal hippocampus is linked to spatial navigation and memory formation, whereas the ventral hippocampus is linked to emotional regulation. Here, we provide the first combined transcriptomic and proteomic profiling that reveals striking differences between dorsal and ventral hippocampus. Using various acute stress challenges we demonstrate that both regions display very distinct molecular responses, and that the ventral hippocampus is particularly responsive to the effects of stress. We demonstrate that separately analyzing dorsal and ventral hippocampus greatly increases the ability to detect region-specific stress effects, and we identify an epigenetic network, which is specifically sensitive to acute stress in the ventral hippocampus.
Project description:Characterization of gene expression in blood after single and repetitive SCUBA diving to 18 meters while breathing compressed air or a mixture of 36 percent oxygen and 64 percent nitrogen.