5-HT1A receptors within the intermediate lateral septum modulate stress vulnerability in male mice

Chronic stress is a major risk factor for psychiatric disorders. However, certain individuals may be at higher risk due to greater stress susceptibility. Elucidating the neurobiology of stress resilience and susceptibility may facilitate the development of novel strategies to prevent and treat stress-related disorders such as depression. Mounting evidence suggests that the serotonin (5-HT) system is a major regulator of stress sensitivity. In this study, we assessed the functions of 5-HT1A and 5-HT2A receptors within the lateral septum (LS) in regulating stress vulnerability. Among a group of male mice exposed to chronic social defeat stress (CSDS), 47.2% were classified as stress-susceptible, and these mice employed more passive coping strategies during the defeat and exhibited more severe anxiety- and depression-like behaviors during the following behavioral tests. These stress-susceptible mice also exhibited elevated neuronal activity in the LS as evidenced by greater c-Fos expression, greater activity of 5-HT neurons in both the dorsal and median raphe nucleus, and downregulated expression of the 5-HT1A receptor in the intermediate LS (LSi). Finally, we found the stress-induced social withdrawal symptoms could be rapidly relieved by LSi administration of 8-OH-DPAT, a 5-HT1A receptor agonist. These results indicate that 5-HT1A receptors within the LSi play an important role in stress vulnerability in mice. Therefore, modulation of stress vulnerable via 5-HT1A receptor activation in the LSi is a potential strategy to treat stress-related psychiatric disorders.

GABAergic synapses from the ventral lateral septum to the paraventricular nucleus of hypothalamus modulate anxiety

Emotional disorders, such as anxiety and depression, represent a major societal problem; however, the underlying neurological mechanism remains unknown. The ventral lateral septum (LSv) is implicated in regulating processes related to mood and motivation. In this study, we found that LSv GABAergic neurons were significantly activated in mice experiencing chronic social defeat stress (CSDS) after exposure to a social stressor. We then controlled LSv GABAergic neuron activity using a chemogenetic approach. The results showed that although manipulation of LSv GABAergic neurons had little effect on anxiety-like behavioral performances, the activation of LSv GABAergic neurons during CSDS worsened social anxiety during a social interaction (SI) test. Moreover, LSv GABAergic neurons showed strong projections to the paraventricular nucleus (PVN) of the hypothalamus, which is a central hub for stress reactions. Remarkably, while activation of GABAergic LSv-PVN projections induced social anxiety under basal conditions, activation of this pathway during CSDS alleviated social anxiety during the SI test. On the other hand, the chemogenetic manipulation of LSv GABAergic neurons or LSvGABA-PVN projections had no significant effect on despair-like behavioral performance in the tail suspension test. Overall, LS GABAergic neurons, particularly the LSv GABAergic-PVN circuit, has a regulatory role in pathological anxiety and is thus a potential therapeutic target for the treatment of emotional disorders.

Dopamine D2 receptor within the intermediate region of the lateral septum modulate social hierarchy in male mice

The dopamine (DA) system has long been involved in social hierarchies; however, the specific mechanisms have not been elucidated. The lateral septum (LS) is a limbic brain structure that regulates various emotional, motivational, and social behaviors. DA receptors are abundantly expressed in the LS, modulating its functions. In this study, we evaluated the functions of DA receptors within different subregions of the LS in social dominance using a confrontation tube test in male mice. The results showed that mice living in social groups formed linear dominance hierarchies after a few days of cohousing, and the subordinates showed increased anxiety. Fos expressions was elevated in the entire LS after a confrontation tube test in the subordinates. However, DA neurons were more activated in the dominates within the ventral tegmental area and the dorsal raphe nucleus. Quantitative real-time polymerase chain reaction results showed that D2 receptor (D2R) within the intermediate region of the LS (LSi) were elevated in the subordinate. In the following pharmacological studies, we found simultaneous D2R activation in the dominants and D2R inhibition in the subordinates switched the original dominant-subordinate relationship. The aforementioned results suggested that D2R within the LSi plays an important role in social dominance in male mice. These findings improve our understanding of the neural mechanisms underlying the social hierarchy, which is closely related to our social life and happiness.

Dopamine D2 receptors in the dorsomedial prefrontal cortex modulate social hierarchy in male mice

Social hierarchy greatly influences behavior and health. Both human and animal studies have signaled the medial prefrontal cortex (mPFC) as specifically related to social hierarchy. Dopamine D1 receptors (D1Rs) and D2 receptors (D2Rs) are abundantly expressed in the mPFC, modulating its functions. However, it is unclear how DR-expressing neurons in the mPFC regulate social hierarchy. Here, using a confrontation tube test, we found that most adult C57BL/6J male mice could establish a linear social rank after 1 week of cohabitation. Lower rank individuals showed social anxiety together with decreased serum testosterone levels. D2R expression was significantly downregulated in the dorsal part of mPFC (dmPFC) in lower rank individuals, whereas D1R expression showed no significant difference among the rank groups in the whole mPFC. Virus knockdown of D2Rs in the dmPFC led to mice being particularly prone to lose the contests in the confrontation tube test. Finally, simultaneous D2R activation in the subordinates and D2R inhibition in the dominants in a pair switched their dominant-subordinate relationship. The above results indicate that D2Rs in the dmPFC play an important role in social dominance. Our findings provide novel insights into the divergent functions of prefrontal D1Rs and D2Rs in social dominance, which may contribute to ameliorating social dysfunctions along with abnormal social hierarchy.

5-HT1A receptor in the central amygdala and 5-HT2A receptor in the basolateral amygdala are involved in social hierarchy in male mice

Most social animals self-organize into dominance hierarchies that strongly influence their behavior and health. The serotonin (5-HT) system is believed to play an important role in the formation of social hierarchy. 5-HT receptors are abundantly expressed in the amygdala, which is considered as the central node for the perception and learning of social hierarchy. In this study, we assessed the functions of various 5-HT receptor subtypes related to social rank determination in different subregions of the amygdala using the confrontation tube test in mice. We revealed that most adult C57BL/6 J male mice exhibited a linear social rank after a few days of cohousing. The tube test ranks were slightly related to anxiety-like behavioral performance. After the tube test, the amygdala and 5-HT neurons in the dorsal raphe nucleus were activated in lower-rank individuals. Quantitative real-time polymerase chain reaction analysis revealed that despite the high expression of 5-HT1A receptor mRNA in the central amygdala (CeA), 5-HT2A receptor mRNA expression was downregulated in the basolateral amygdala (BLA) in higher-rank individuals. The dominant-subordinate relationship between mouse pairs could be switched via pharmacological modulation of these receptors in CeA and BLA, suggesting that these expression changes are essential for establishing social ranks. Our findings provide novel insights into the divergent functions of 5-HT receptors in the amygdala related to social hierarchy, which is closely related to our health and welfare.

[Preliminary report on the use of total lumpectomyconical remnant gastric - esophagus side overlap anastomosis in radical resection of Siewert type II proximal gastric cancer]

Objective: There is no standard method for esophageal remnant gastric reconstruction for proximal gastrectomy. Reflux esophagitis caused by esophagogastrostomy remains a difficult surgical problem. To report the preliminary surgical results of novel esophagus-conical remnant gastric side overlap anastomosis (CGEO) , with particular emphasis on postoperative esophageal reflux. Methods: In June 2022, we developed a novel CGEO for laparoscopic proximal gastrectomy on two patients with Siewert type II esophagogastric junction adenocarcinoma. Surgical procedures for CGEO: (1) Laparoscopic proximal gastrectomy and preparation of conically shaped gastric remnant; (2) Determining anastomotic site of residual stomach and esophagus; (3) Side-to-side anastomosis of right esophageal wall to anterior of conical gastric remnant; (4) Valvuloplasty of esophageal stump. Results: Case 1 was a 71-year-old man with an operation time of 305 minutes and was successfully discharged from the hospital on the 9th day after surgery, and the postoperative pathology was T3N0M0. Case 2 was an 82-year-old man with an operation time of 325 minutes. He was discharged on the 10th day after surgery. In both cases, only mild esophageal mucosal changes were seen in gastroscopy, there were no obvious symptoms of esophageal reflux. There was also no significant weight change at half a year after operation. Conclusion: CGEO is moderately safe in radical surgery for proximal gastric cancer, and may have a preventive effect on the occurrence of postoperative esophageal reflux, but long-term results need to be confirmed by further studies with follow-up.

[Three-dimensional analysis of maxillary dentition during molar distalization with clear aligners under different movement designs: an in vitro experiment]

Objective: To investigate the three-dimensional force in the maxillary dentition under different movement designs for molar distalization with clear aligners Methods: Three groups were designed: simultaneous movement group (simultaneous distalization of maxillary first and second molars), second molar movement group (distalization of maxillary second molars) and first molar movement group (distalization of maxillary first molars). Ten clear aligners were made in each group, and the displacement was designed to be 0.2 mm. A force sensing device was established to measure the three-dimensional force on the upper dentition with the clear aligner. The device contained a model of the maxillary dentition consisting of 14 teeth, each tooth connected to an individual sensor. After the clear aligner was fitted, the data of 14 sensors were collected and analyzed using computer analysis software. The moving teeth were taken as the target teeth, and the rest of the teeth were anchorage. The data of the three-dimensional force in the three groups in each tooth position were measured and compared. Results: The sagittal forces on the first and second molars in the simultaneous movement group were (5.61±0.94) and (5.81±1.08) N, respectively, which were significantly smaller than those of the target teeth in the same position in other groups (P<0.05). The second molars in the first molar movement group received a sagittal reaction force, which was (-6.73±1.99) N. The anterior teeth in the three groups were all subjected to sagittal reaction force, and the force value was in a range of (-3.33 to 0.46) N. In the coronal direction, the second premolars of the simultaneous movement group received the reaction force in the palatal direction, and the force value was (-2.17±1.06) N. The first molars in the second molar movement group were also subjected to palatal reaction force of (-1.99±0.70) N. The second molars and second premolars in the first molar movement group were also subjected to palatal reaction force, which were (-2.85±0.57) and (-1.85±0.74) N, respectively. Compared with the sagittal and coronal forces, the target teeth and anchorage teeth in the three groups were less stressed in the vertical direction. Conclusions: The first and second molars distalized simultaneously, the correction force in the sagittal direction was relatively small. When first molar was moved distally alone, a greater reaction force in the sagittal direction was exerted on the second molar. Buccal displacement of the adjacent anchorage teeth should be designed to counteract the palatal reaction force on the anchorage teeth as the molars moved distally.

Increased Lactobacillus abundance contributes to stress resilience in mice exposed to chronic social defeat stress

INTRODUCTION

Accumulating evidence indicates that abnormalities in the composition of gastrointestinal (GI) microbiota play a vital role in stress-related disorders. Both human beings and animals perceive stressful events differently, i.e., resilience or susceptibility. However, the role of GI microbiota in stress resilience/susceptibility and the underlying mechanisms remain largely unknown.

METHODS & RESULTS

Sixty male C57BL/6J mice were exposed to 10-day chronic social defeat stress (CSDS), and 28 were found to be resilient to CSDS. We next analyzed microbiota compositions in the cecum using 16S rDNA gene sequencing, which revealed a significant increase in the relative abundance of Lactobacillus at the genus level in the resilient mice. In subsequent experiments, we found that oral administration of a strain of Lactobacillus (Lactobacillus murinus) for 2 weeks attenuated the increased levels of stress-induced corticosterone and anxiety-like behavior in stress-susceptible mice. The mRNA expression of tryptophan hydroxylase 2 (a rate-limiting enzyme in 5-HT synthesis) was also significantly increased in the dorsal raphe nucleus (DR) of stress-susceptible mice.

CONCLUSIONS

Lactobacillus contributes to stress resilience, and the DR 5-HT system may play an important role during this process. The above results suggest that certain organisms in the GI tract may play an essential role in stress response and be useful in the prevention and treatment of some stress-related psychiatric disorders, such as depression.

[Clinical observation on cluster acupuncture at scalp points combined with exercise therapy in treatment of limb spasm after stroke]

OBJECTIVE

To observe the clinical effect of cluster acupuncture at scalp points in treating limb spasm after stroke on the basis of conventional exercise therapy.

METHODS

A total of 72 patients with limb spasm after stroke were randomly divided into an observation group (36 cases, 5 cases dropped off) and a control group (36 cases, 6 cases dropped off). The control group was treated with exercise therapy. In the observation group, on the basis of the control group, penetrating technique of acupuncture was exerted at Qianding (GV 21) to Baihui (GV 20), Xinhui (GV 22) to Qianding (GV 21), etc. once a day, 5 days a week for 4 weeks. Before and after treatment, the changes of the modified Ashworth scale (MAS), simplified Fugl-Meyer motor assessment (FMA), and modified Barthel index (MBI) scores of the two groups were compared.

RESULTS

After treatment, the MAS scores of upper and lower limbs in the two groups were lower than before treatment (P<0.05), and those in the observation group were lower than the control group (P<0.05). After treatment, the scores of FMA and BMI in the two groups were higher than before treatment (P<0.05), and the score of MBI in the observation group was higher than the control group (P<0.05).

CONCLUSION

On the basis of conventional exercise therapy, cluster acupuncture at scalp points can reduce the spasm, improve motor function and activities of daily living in patients with limb spasm after stroke.

Regulatory T-cell depletion in the gut caused by integrin β7 deficiency exacerbates DSS colitis by evoking aberrant innate immunity

Integrin α4β7 controls lymphocyte trafficking into the gut and has essential roles in inflammatory bowel disease (IBD). The α4β7-blocking antibody vedolizumab is approved for IBD treatment; however, high dose of vedolizumab aggravates colitis in a small percentage of patients. Herein, we show that integrin β7 deficiency results in colonic regulatory T (Treg) cell depletion and exacerbates dextran sulfate sodium (DSS) colitis by evoking aberrant innate immunity. In DSS-treated β7-deficient mice, the loss of colonic Treg cells induces excessive macrophage infiltration in the colon via upregulation of colonic epithelial intercellular adhesion molecule 1 and increases proinflammatory cytokine expression, thereby exacerbating DSS-induced colitis. Moreover, reconstitution of the colonic Treg cell population in β7-deficient mice suppresses aberrant innate immune response in the colon and attenuates DSS colitis. Thus, integrin α4β7 is essential for suppression of DSS colitis as it regulates the colonic Treg cell population and innate immunity.

Direct cloning of the unknown flanking DNA fragments from a large insert without restriction mapping

A simple technique for direct cloning of the target DNA fragments from a large insert according to its adjacent known sequence is described here. In this new subcloning method, a large DNA insert is digested and ligated with a linearized plasmid vector to construct a subclone library that is subjected to screening. The bacterial clones in this library are individually picked, grown in a 96-well plate, and then pooled across the rows or columns. Target clones are obtained from the ordered separate pools by PCR-screening with a set of primers, one specific for the adjacent known sequence and the other serving as "anchor primer" specific for the vector sequence. This direct subcloning procedure was efficiently demonstrated by cloning a specific DNA region from a large insert within 2 days without mapping the starting DNA or isolating the digested DNA fragment.

Organization of human ACAT-2 gene and its cell-type-specific promoter activity

Acyl-CoA:cholesterol acyltransferase (ACAT) plays important roles in cellular cholesterol homeostasis. Two ACAT genes exist in mammals. We report here the genomic organization of human ACAT-2 gene and analysis of its promoter activity in various cell lines. The human ACAT-2 gene spans over 18 kb and contains 15 exons. Three transcription start sites and one poly(A) site are identified by the 5'/3'-RACE. In addition, the human ACAT-2 gene is linked to the insulin-like growth factor binding protein 6 (IGFBP-6) gene in a head-to-tail manner with a small intergenic region of about 1.2 kb. The 5'-flanking region of human ACAT-2 gene contains many potential cis-acting elements for multiple transcriptional regulatory factors but lacks TATA and CCAAT boxes. Using promoter-luciferase reporter assays, we demonstrate the transcriptional activity of ACAT-2 gene promoter is high in Caco-2 cells, especially after these cells become postconfluent and behave as intestinal enterocytes.

Covalent structures of BmK AS and BmK AS-1, two novel bioactive polypeptides purified from Chinese scorpion Buthus martensi Karsch

Complete amino acid sequences of two novel bioactive polypeptides, each containing 66 amino acid residues, BmK AS and BmK AS-1 purified from the venom of Chinese scorpion Buthus martensi Karsch, have been determined by Edman sequencing and mass spectrometry on native proteins, reduced and S-carboxymethylated proteins and their peptides obtained after cleavage with proteolytic enzymes. Sequence analysis showed 86.4% structural identity between BmK AS and BmK AS-1 and also a high sequence similarity between BmK ASs and AaH IT4, a unique anti-insect toxin and a ligand of Na+ channels obtained from Sahara scorpion A. australis Hector, but poor sequence homology between BmK ASs and those of the known alpha-, beta-type and long-chain insect-selective type scorpion neurotoxins. The positions of four disulfide bridges in BmK AS-1 were established as Cys-12 and Cys-62, Cys-16 and Cys-37, Cys-23 and Cys-44, and Cys-27 and Cys-46, which are the same as those in alpha- and beta-scorpion neurotoxins. These results suggest that BmK ASs and AaH IT4 may form a new group sharing similar structural and functional properties in the family of scorpion neurotoxic polypeptides.

Evaluation of the effect of butyl p-hydroxybenzoate on the proteolytic activity and membrane function of human spermatozoa

The inhibition of the proteolytic activity of acrosin in human spermatozoa by butyl p-hydroxybenzoate was assessed by the gelatin substrate film method. Compared with a typical acrosin inhibitor, TLCK, the inhibitory activity of butyl p-hydroxybenzoate to acrosin was much more effective (20 times) than that of TLCK, proving that butyl p-hydroxybenzoate was a potent acrosin inhibitor. The effect of butyl p-hydroxybenzoate on membrane function of human spermatozoa was evaluated using a sperm-tail hypoosmotic swelling test and supravital stain method. A good correlation (r = 0.92) was observed between the % spermatozoa with normal membrane function and the % live spermatozoa after treatment of the spermatozoa with butyl p-hydroxybenzoate for 1 min, indicating that the death of spermatozoa caused by butyl p-hydroxybenzoate is probably due to impairment of sperm membrane function. Both the inhibitory effect on acrosin and the adverse effect on membrane function suggest that butyl p-hydroxybenzoate could be developed as a new vaginal contraceptive.

Computer-assisted image analysis of sperm concentration in human semen before and after swim-up separation: comparison with assessment by haemocytometer

Evaluation of male fertility is based predominantly on results from semen analysis and determination of the sperm concentration is one of the main parameters of the analysis. The availability of a fully automated videomicrographic digital image analyser would offer both an objective and rapid method for determination of the sperm concentration. In the present study the sperm concentration in 327 semen samples was determined by haemocytometer according to the World Health Organization guidelines, and also by a computer-assisted digital image analyser system. Results were classified according to the routine procedure (haemocytometer) before statistical analyses. The computerized measurements caused a shift to the right in the frequency distribution of sperm concentration. Sperm concentrations were more often overestimated significantly (P less than 0.001) by the computerized measurements in semen samples with concentrations up to 80.0 x 10(6)/ml. This overestimation seemed to be caused by the presence of particles in seminal plasma that were recognized incorrectly as sperm by the computer program. The computerized digital image analyser gave an average sperm concentration of 2.2 +/- 0.6 x 10(6)/ml (mean +/- SEM) in 17 azoospermic semen samples while the routine procedure did not detect the presence of sperm cells. After removing the seminal plasma by washing and centrifugation with culture medium, and using the swim-up procedure to harvest motile sperm, the computerized measurements showed comparable results with the routine procedure for those sperm preparations (n = 44) with sperm concentrations greater than 5.0 x 10(6)/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro spermicidal activity of parabens against human spermatozoa

Potent in vitro spermicidal activity of parabens against human spermatozoa was demonstrated in this study. The "pass" point concentration of the four parabens--methylparaben, ethylparaben, propylparaben, and butylparaben, at which all spermatozoa were immobilized and no immobilized spermatozoon revived after 30 min incubation in phosphate buffered glucose solution, was 6, 8, 3, and 1 mg/ml, respectively, as tested by Harris' method. These parabens are used as food and pharmaceutic preservatives; less toxicity and side effects were expected for the development of parabens as vaginal contraceptive agents.