Biology subjects

Hung, W.-C.

Publications and source records attributed to Hung, W.-C..

6 recordsLinked to original sources

bioRxiv2025

Pharmacological and Physiological Characteristics of Synaptic Transmissions from the Medial Prefrontal Cortex onto Noradrenergic Neurons and Their Presynaptic Neurons in the Mouse Locus Coeruleus

The locus coeruleus (LC) is the primary source of norepinephrine in the brain and is known to modulate brain-wide arousal state. Recent evidence suggests that it also regulates immediate attentional responses by resetting related cortical networks to optimize behavioral outcomes. Cortical regions of high cognitive function, such as the medial prefrontal cortex (mPFC), are theorized to directly influence LC output for the purpose of behavioral regulation. However, the available evidence is insufficient to provide a comprehensive understanding of the underlying mechanisms and properties. To provide further comprehensive data on this issue, we combined ex vivo whole-cell recording with an optogenetic approach to study the synaptic transmission of mPFC inputs to LC neurons, including noradrenergic (NA) neurons and GABAergic neurons presynaptic to them (preLC neurons). Our findings indicate that the mPFC exhibits monosynaptic connections with both NA and GABAergic preLC neurons. These synaptic connections demonstrate cell-type-specific disparities in glutamate release properties. In comparison to those on GABAergic preLC neurons, the mPFC fibers synapsing on LC-NA exhibit a lower release probability (higher paired-pulse ratio) and demonstrate a presynaptic enhancement of glutamate release efficacy during behavior. The features of simultaneous connections onto LC-NA and GABAergic preLC neurons, which exhibit cell-type-specific differences in plastic function of the transmitter release, enable the mPFC to effectively multiplex information to the LC for the adaptive regulation of behavior.

neuroscience↗

bioRxiv2025

Interplay between Skin Sympathetic Nerve Activity and Gut Microbiota, the Neurocardiac Axis in Acute Coronary Syndrome

BACKGROUNDPrevious studies have linked gut dysbiosis to the acute coronary syndrome (ACS) and sympathetic nervous system disturbances. However, the relationship between skin sympathetic nerve activity (SKNA) and gut microbiota in ACS patients remains largely unexplored. We hypothesize that elevated SKNA may interact with specific microbial profiles in ACS. METHODS AND RESULTSFifteen ACS patients with age- and sex-matched controls were enrolled in the cross-sectional study. Subjects with type 2 diabetes or on antibiotics, proton pump inhibitors, or metformin were excluded. Demographic and clinical data were recorded, and SKNA was measured by neuECG. Gut microbial profiles were analyzed by sequencing the V3-V4 region of the 16S rRNA gene. Significant differences in alpha diversity, including Chao 1 index and Faiths phylogenetic diversity, were observed between the ACS and control groups (P<0.001). Distinct beta diversity between the two groups was also identified using unweighted normalized UniFrac analysis (P=0.001). Redundancy analysis and Mantel test revealed a significant relationship between SKNA and microbial profiles. Several butyrate-producing bacteria were decreased in the ACS group, while the genus Hungatella, a trimethylamine producer, showed a significant increase and was positively correlated with SKNA. Additionally, predicted microbial functional analysis indicated an elevation in branched-chain amino acid biosynthesis in the ACS group. CONCLUSIONSThis study is the first to establish an association between SKNA and gut microbial profiles in ACS patients. SKNA can serve as a biomarker for ACS, offering a simple and non-invasive tool to explore the interaction between the nervous system and gut microbiota in cardiovascular diseases. Clinical PerspectiveO_ST_ABSWHAT IS NEW?C_ST_ABSThe Skin sympathetic nerve activity (SKNA) is a novel and non-invasive recording of the sympathetic nervous system from the skin of patients. The NEW findings in our study from acute coronary syndrome (ACS) patients are (1) to establish the correlation between SKNA, heart rate variability and microbiota, (2) the Hungatella is correlated with SKNA and standard deviation of NN intervals (SDNN). WHAT ARE THE CLINICAL IMPLICATIONS?Since microbiota and sympathetic nervous system (SNS) might be essential factors of ACS, it is important to assess the abundance of microbiota and SNS activity for accurate management of ACS. The Hungatella, one of the microbiota involved in atherosclerotic cardiovascular disease, heart failure, inflammatory process, and anxiety disorder, might be the link between SNS and ACS. In our study, we prove the positive association between Hungatella and SKNA. Therefore, by checking the SKNA of patients with ACS, we might discover the SNS activity and also the underlying microbiota etiology of ACS. Then, it is critical and accurate to target Hungatella in ACS patients with high SKNA to reduce the risk of ACS.

microbiology↗

bioRxiv2025

The activation of fibroblast growth factor receptor 1 provides therapeutic benefit in a mouse model of Alzheimer's disease

Alzheimers disease (AD) is a neurodegenerative disease that is characterized by the accumulation of amyloid plaque and neurofibrillary tangles, ultimately impairing multiple cognitive domains. Both plaques and tangles cause neuronal damage and stimulate inflammatory responses in glial cells. The fibroblast growth factor receptor 1 (FGFR1)-mediated signaling pathways support the function of damaged neurons and modulate inflammatory response. The FGFR1 agonists, including Fibroblast growth factor 1 (FGF1) and FG loop peptide (FGL), have been implicated in multiple disease therapy. Whether FGFR1 agonists can improve pathology and cognitive function in AD remains unknown. Here, we showed that administration of FGF1 and FGL to the AD mouse model reversed spatial memory impairment, enhanced neurogenesis, suppressed reactive astrogliosis, and restricted dystrophic neurite. However, only FGF1 treatment reduced the deposition of senile plaque. In microglial culture studies, FGF1 improves the phagocytosis ability of microglia, which contributes to the clearance of plaques. Together, our findings suggested that FGFR1 agonists alleviate pathology and cognitive impairment via immunomodulatory and improve neuronal health in the AD mouse model. HighlightsFGFR1 agonists alleviate memory deficits in AD mice. FGFR1 agonists increase adult neurogenesis and limit dystrophic neurites in AD mice. FGFR1 agonists increase plaque-associated microglia in vivo and promote phagocytosis in vitro.

neuroscience↗

bioRxiv2025

Axon collateral pattern of a sparse locus coeruleus norepinephrine neuron in mouse cerebral cortex.

The locus coeruleus (LC) contains predominantly norepinephrine (NE) neurons that project widely throughout the brain. The LC plays a critical role in controlling behavior, particularly arousal. Historically, it was thought that the LC-NE system performed its behavioral control function by uniformly releasing NE throughout most brain regions. However, recent evidence suggests that the LCs cortical projections are organized into modules, which allows for the coordination of diverse, and sometimes opposing, functions such as fear memory formation and extinction. Nevertheless, many details remain unclear and require data from the axon collaterals of sparse neurons. We modified a viral tracing protocol using a dual-recombinase system to trace the axonal collaterals of sparse LC neurons projecting to the cingulate cortex (CgC). Our results show that even a small number of LC neurons have broad cortical projections, though the pattern is not uniform. Centered-log ratio transformation of NE fiber distribution across the cortex and hippocampus reveals a few preferential target areas (PTAs) of the labeled LC-NE neurons axonal projections. The summed NE fiber length in these defined PTs is enriched relative to the geometric mean of all other cortical and hippocampal regions where NE fibers were detected. Notably, the defined PTAs--including the rostral splenial cortex, dorsal hippocampus, somatosensory cortex, and CgC (the retrograde viral labeling injection site)--are functionally related to navigation. These results demonstrate that LC-NE neurons are organized into distinct projection modules, each comprising a small number of neurons with functionally correlated major cortical targets.

neuroscience↗

bioRxiv2022

Assessment of genetic diversity and SNP marker development within peanut germplasm in Taiwan by RAD-seq

The cultivated peanut (Arachis hypogaea L.) is an important oil crop but has a narrow genetic diversity. Molecular markers can be used to probe the genetic diversity of various germplasm. In this study, the restriction site associated DNA (RAD) approach was utilized to sequence 31 accessions of Taiwanese peanut germplasm, leading to the identification of a total of 17,610 single nucleotide polymorphisms (SNPs). The origin of these 31 accessions is contrasted so the global subset (n = 17) has greater genetic diversity than the local subset (n = 14). Concerning botanical varieties, the var. fastigiata subset has greater genetic diversity than the other two subsets of var. vulgaris and var. hypogaea, suggesting that novel genetic resources should be introduced into breeding programs to enhance genetic diversity. Principal component analysis (PCA) using genotyping data separated the 31 accessions into three clusters largely according to the botanical varieties, consistent with the PCA result for 282 accessions genotyped by 14 kompetitive allele-specific PCR (KASP) markers developed in this study. The SNP markers identified in this work not only revealed the genetic relationship and population structure of current germplasm in Taiwan, but also offer an efficient tool for breeding and further genetic applications.

genetics↗

bioRxiv2018

Emergence of mosaic plasmids harboring Tn1546-ermB element in Staphylococcus aureus isolates

Antimicrobial resistance in Staphylococcus aureus is a major problem and the acquisition of resistance genes may occur by horizontal gene transfer (HGT). The transposon, an important means of HGT, is recognized as a mobile genetic element that can integrate in plasmids, replicate and transfer to other strains. We have previously reported a novel structure of the Enterococcus faecium-originated Tn1546-ermB element in S. aureus. The emergence of the Tn1546-like element is an emerging problem that requires continuous monitoring. In the present study, we expand the examination of Tn1546-ermB element to ermB-positive methicillin-susceptible S. aureus (MSSA) (n = 116) and ermB-positive methicillin-resistant S. aureus (MRSA) (n = 253) during a 16-year period, from 2000 to 2015. PCR mapping showed that 10 MSSA and 10 MRSA carried the Tn1546-ermB element. The 10 MSSA belonged to three sequence types (ST), ST7 (n = 6), ST5 (n = 3), and ST59 (n = 1), and the 10 MRSA belonged to two STs, ST188 (n = 8) and ST965 (n = 2). Since only clonal complex 5 (including ST5, ST85, ST231, and ST371) MRSA, ST8 MRSA and ST5 MSSA have been previously reported to carry Tn1546 plasmids, this is the first report describing the presence of the Tn1546-ermB element in ST7/5/59 MSSA and ST188/965 MRSA. Plasmid sequencing revealed that the Tn1546-ermB element was harbored by five different mosaic plasmids. In addition to resistance genes, some plasmids also harbored toxin genes.

microbiology↗