Microglial activation during aging is associated with neuroinflammation and cognitive impairment. Galectin-3 plays a crucial role in microglial activation and phagocytosis. However, the role of galectin-3 in the aged brain is not completely understood. In the present study, we investigated aging-related mechanisms and microglial galectin-3 expression in the mouse hippocampus using female 6-, 12-, and 24-month-old C57BL/6 mice. Western blot analysis revealed neurodegeneration, blood-brain barrier leakage, and increased levels of neuroinflammation-related proteins in 24-month-old mice compared to 6- and 12-month-old mice. Immunohistochemistry revealed an increase in activated microglia in the hippocampus of 24-month-old mice compared to 6- and 12-month-old mice. Furthermore, we found more galectin-3 and triggering receptor expressed on myeloid cells-2-positive microglia in 24-month-old mice compared to 6- and 12-month-old mice. Using primary mouse microglial cells, galectin -3 was also increased by lipopolysaccharide treatment. These findings suggest that galectin-3 may play an important role in microglial activation and neuroinflammation during brain aging.

The 5-hydroxytryptamine type3 (5-HT3 ) receptor, a ligand-gated ion channel, plays a critical role in synaptic transmission. It has been implicated in various neuropsychiatric disorders. This study aimed to elucidate the mechanism by which quetiapine, an atypical antipsychotic, could inhibit 5-HT3 receptor-mediated currents in NCB20 neuroblastoma cells. Whole-cell patch-clamp recordings were used to study effects of quetiapine on receptor ion channel kinetics and its competitive antagonism. Co-application of quetiapine shifted 5-HT concentration-response curve rightward, significantly increasing the EC50 without altering the maximal response (Emax ), suggesting a competitive inhibition. Quetiapine's IC50 varied with 5-HT concentration and treatment condition. The IC50 value of quetiapine was 0.58 μM with 3μM 5-HT and 25.23 μM with 10 μM 5-HT, indicating an inverse relationship between quetiapine efficacy and agonist concentration. Pretreatment of quetiapine significantly enhanced its inhibitory potency, reducing its IC50 from 25.23 μM to 0.20 μM.Interaction kinetics experiments revealed an IC50 of 5.17 μM for an open state of the 5-HT3 receptor, suggesting weaker affinity during receptor activation. Quetiapine also accelerated receptor deactivation and desensitization, suggesting that it could stabilize the receptor in non-conducting states. Additionally, quetiapine significantly prolonged recovery from desensitization without affecting recovery from deactivation, demonstrating its selective impact on receptor kinetics. Inhibition of the 5-HT3 receptor by quetiapine was voltage-independent, and quetiapine exhibited no usedependency, further supporting its role as a competitive antagonist. These findings provide insights into inhibitory mechanism of quetiapine on 5-HT3 receptor and suggest its potential therapeutic implications for modulating serotonergic pathways in neuropsychiatric disorders.

Haloperidol is a typical antipsychotic drug effective in alleviating positive symptoms of schizophrenia by blocking dopamine receptor 2 (DR2). However, it is also known to produce neuropsychiatric effects by acting on various targets other than DR. In this study, we investigated effect of haloperidol on function of 5-hydroxytryptamine (5-HT) 3 receptor, a ligand-gated ion channel belonging to the serotonin receptor family using the whole-cell voltage clamp technique and NCB20 neuroblastoma cells. When co-applied with 5-HT, haloperidol inhibited 5-HT3 receptormediated currents in a concentration-dependent manner. A reduction in maximal effect (E max ) and an increase in EC 50 observed during co-application indicated that haloperidol could act as a non-competitive antagonist of 5-HT3 receptors. Haloperidol inhibited the activation of 5-HT3 receptor, while also accelerating their deactivation and desensitization. The inhibitory effect of haloperidol showed no significant difference between pre- and co-application. Haloperidol did not alter the reversal potential of 5-HT3 receptor currents. Furthermore, haloperidol did not affect recovery from deactivation or desensitization of 5-HT3 receptors. It did not show a use-dependent inhibition either. These findings suggest that haloperidol can exert its inhibitory effect on 5-HT3 receptors by allosterically preventing opening of ion channels. This mechanistic insight enhances our understanding of relationships between 5-HT3 receptors and pharmacological actions of antipsychotics.

Objective: Ciprofloxacin (CPFX) is frequently prescribed by fertility specialists and urologists to manage infections in male reproductive organs. However, it is toxic to the testicles and can lead to infertility. Dietary antioxidants are known to protect the testis from damage. This study aimed to investigate the effects of coenzyme Q10 (CoQ10) on the adverse side effects of CPFX using stereological methods. Methods: Sixty rats were divided into six groups: control (distilled water), CoQ10 (10 mg/kg/day), and low-dose (103 mg/kg/day) and high-dose (206 mg/kg/day) of CPFX (LD-CPFX, HD-CPFX) with or without CoQ10 consumption. The treatments lasted for 45 days. Sperm count, serum testosterone levels, and testicular parameters were evaluated. Results: Significant decreases in sperm count, motility, normal morphology, viability, and testosterone levels were observed in the LD-CPFX (p<0.003) and HD-CPFX- treated rats (p=0.0001) compared to the control groups. A 10% to 36% reduction in the volume of seminiferous tubules, tubular epithelium, and tubule length was noted in LD-CPFX (p<0.01) and HD-CPFX-treated rats (p<0.006), while the volume of the interstitium increased by 25% to 28% in LD-CPFX (p=0.03) and HD-CPFX (p=0.008) groups. The number of cells, including spermatogonia, spermatocytes, spermatids, Sertoli cells, and Leydig cells, decreased by 36% to 75% in the testes exposed to LD-CPFX (p<0.04) and HD-CPFX (p<0.01), compared to the control groups. However, these changes normalized in rats that received CoQ10. Conclusion CPFX exposure for 45 days, regardless of the dose, has detrimental effects on testicular parameters. CoQ10 can prevent CPFX-induced testicular structural impairments.

Valproic acid (VPA), widely used as an antiepileptic drug, exhibits developmental neurotoxicity when exposure occurs during early or late pregnancy, resulting in various conditions ranging from neural tube defects to autism spectrum disorders. However, toxicity during the very early stages of neural development has not been addressed. Therefore, we investigated the effects of VPA in a model where human pluripotent stem cells differentiate into anterior or posterior neural tissues. Exposure to VPA during the induction of neural stem cells induced different developmental toxic effects in a dose-dependent manner. For instance, VPA induced cell death more profoundly during anteriorly guided neural progenitor induction, while inhibition of cell proliferation and enhanced differentiation were observed during posteriorly guided neural induction. Furthermore, acute exposure to VPA during the posterior induction step also retarded the subsequent neurulation-like tube morphogenesis process in neural organoid culture. These results suggest that VPA exposure during very early embryonic development might exhibit cytotoxicity and subsequently disrupt neural differentiation and morphogenesis processes.

Background: and Purpose The pathogenesis of neurovascular diseases and various types of dementia is tightly connected to cerebral circulation. An area that requires further exploration is the system of deep cerebral perforating arteries—arteries branching directly from high-pressure intracranial arteries, supplying vital neural structures such as the internal capsule, and characterized by a diameter of well below 1 mm, which makes them difficult to visualize with standard radiological examinations. This study aimed to analyze the morphology of the perforator origins, which constitute connection points between high-pressure intracranial arteries and microcirculation. Methods: Twenty-three human basal ganglia specimens with the middle cerebral artery (MCA, including 172 perforating arteries) and ten brainstem specimens with the basilar artery (BA, including 162 perforating arteries) were prepared and scanned using microcomputed tomography. The geometry and structure of the perforating arteries were analyzed using radiological images and additional histological studies. Results: The ostia of the perforating arteries were ellipsoidal in shape with median stenosis severity of 23% and 20% for MCA and BA perforators, respectively. The local narrowing structure was typical of neointimal hyperplasia. Statistical analysis revealed that the severity of stenosis may be related to age and cardiovascular health. Conclusion Origins of the deep cerebral perforators are locally narrowed by neointimal hyperplasia, which may be a protective mechanism to adjust high blood pressure to the microcirculation. The narrowings may lead to chronic hypoperfusion and play a role in the pathophysiology of cerebral small vessel disease.

Background: The Microtubules-associated protein tau (MAPT), alpha-synuclein (SNCA), and leucine zipper tumor suppressor 3 (LZTS3) genes are implicated in neurodegeneration and tumor suppression, respectively. This study investigated the regulatory roles of eugenol on paraquat-altered genes. Results: Forty male Wistar rats divided into five groups of eight rats were used. The control group received normal saline; the Paraquat (PQ)-untreated group received only Paraquat. The low dose of eugenol was 200 mg/kg, the medium dose of eugenol was 400 mg/kg, and the high dose of eugenol was 600 mg/kg. All groups except the control group received 10 mg/kg of PQ orally for 14 days at one-day intervals, allowing PQ in the rats for 28 days.Eugenol treatment started on the 29th and lasted 14 days. Motor impairments were determined using wire string and beam-walk; biomarkers were estimated using cerebellar homogenates, while frozen cerebellum was used to study LZTS3, MAPT, and SNCA gene expression. LZTS3 was significantly suppressed in the PQ-untreated group and highly expressed in the eugenol-treated group. The MAPT and SNCA genes were overexpressed in the PQ-untreated group compared to the control group. Eugenol significantly decreased the expression of these genes compared to that in the PQ-untreated group. Antioxidants were reduced considerably, and oxidative stress markers were increased significantly, which could have caused increased protein fibrillation and reduced limb functionality. Histology revealed that eugenol mitigated the alterations caused by Paraquat. Conclusions PQ can enhance tumor expression in addition to causing neurotoxicity, which decreases limb functionality, while eugenol, an antioxidant, can mitigate the effects of PQ.