It is well known that sex hormones are potential modulators of brain functions and women experience dynamic hormonal changes during the menstrual cycle. Previous animal studies have reported that the variations in sex hormones over the menstrual cycle may affect cognitive function, emotion, and behavior by altering structures and functional connectivity of the brain. Considering the prevalence of certain neuropsychiatric disorders such as mood and anxiety disorders is relatively high in women, as compared with men, fluctuations of sex hormones over the menstrual cycle may influence the human brain and potentially underlie sex differences in clinical features of several neuropsychiatric disorders. There is, however, little evidence regarding the exact mechanisms underlying the effects of sex hormones on the human brain. In this review, we focused on studies to examine structural and functional changes over the menstrual cycles in women and aimed to provide an up-to-date overview of neuroimaging studies regarding the effects of sex hormonal fluctuations on the brain and behaviors.

It is well known that sex hormones are potential modulators of brain functions and women experience dynamic hormonal changes during the menstrual cycle. Previous animal studies have reported that the variations in sex hormones over the menstrual cycle may affect cognitive function, emotion, and behavior by altering structures and functional connectivity of the brain. Considering the prevalence of certain neuropsychiatric disorders such as mood and anxiety disorders is relatively high in women, as compared with men, fluctuations of sex hormones over the menstrual cycle may influence the human brain and potentially underlie sex differences in clinical features of several neuropsychiatric disorders. There is, however, little evidence regarding the exact mechanisms underlying the effects of sex hormones on the human brain. In this review, we focused on studies to examine structural and functional changes over the menstrual cycles in women and aimed to provide an up-to-date overview of neuroimaging studies regarding the effects of sex hormonal fluctuations on the brain and behaviors.

PURPOSE: This study was performed to examine the vascular network of the human iris using flat preparation. METHODS: The ciliary body-iris structures were separated from human eyeballs, and a portion of the irises were treated with trypsin to remove the pigment granules. These iris tissues were unfolded and placed onto glass slides using flat preparation, and the vascular network of each iris was examined by fluorescein microscopy. The ciliary body-iris structures separated from the remaining eyes were stained with hematoxylin-eosin without trypsin treatment and were examined by light microscopy. RESULTS: The long posterior ciliary artery formed several branches before entering the iris root, and such branches formed the major arterial circle of the iris with diverse diameters in the vicinity of the iris root and the ciliary process. In the pupillary margin, the iris vasculature network formed a cone shape and then formed an arcade by connecting to adjacent vasculatures. In the vicinity of the collarette, the iris vasculature network formed the minor arterial circle of the iris with diverse diameters perpendicular to the arcade of the iris network located in the pupillary margin. In the pupillary margin, the capillaries were somewhat thick and connected to the irregular traveling iris vein. CONCLUSIONS: The above findings explain the human iris vascular network and provide a theoretical basis for the sectoral filling of the iris vasculature seen in fluorescein iris angiography.
Cadaver ; Cytological Techniques/*methods ; Humans ; Infant ; Infant, Newborn ; Iris/*blood supply ; Microscopy, Fluorescence ; Ophthalmic Artery/*cytology ; Veins/*cytology

This study was conducted to measure the difference in levels of cerebral metabolites in the right and left hemispheres, gray (GM) and white matter (WM), imaging planes, and anatomical regions of healthy dogs to establish normal variations. Eight male Beagle dogs (1 to 4 years of age; mean age, 2 years) with no evidence of neurologic disease were studied. Using the multi-voxel technique on a 1.5 Tesla magnetic resonance imaging scanner, metabolite values (N-acetyl aspartate [NAA], choline [Cho], creatine [Cr]) were obtained from the frontoparietal WM, parietal GM, temporal GM, occipital GM, thalamus, cerebellum, mid-brain, and pons. There was no significant difference in levels of these metabolites between the right and left in any locations or between the GM and WM in the cerebral hemispheres. However, there were significant differences in metabolite ratios within imaging planes. The NAA/Cr was lower in the cerebellum than other regions and the thalamus had a higher Cho/Cr and lower NAA/Cho ratio than in other regions. The spectral and metabolic values will provide a useful internal reference for clinical practice and research involving multi-voxel magnetic resonance spectroscopy. Measurement of metabolite values in the transverse plane is recommended for comparing levels of regional metabolites.
Animals ; Aspartic Acid ; Cerebellum ; Cerebrum ; Choline ; Creatine ; Dogs* ; Humans ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy* ; Male ; Pons ; Rabeprazole ; Thalamus ; White Matter

Microglia regulate the secretion of various immunomediators in central nervous system diseases. Microglial autophagy is the crucial process for cell's survival and cytokine productions. Recent studies have reported that several microRNAs are involved in the autophagy system. miR-Let7A is such a microRNA that plays a role in various inflammation responses, and is magnified as a key modulator particularly in the autophagy system. In present study, we investigated whether miR-Let7A is involved in autophagy in activating microglia. Overexpression of miR-Let7A in LPS-stimulated BV2 microglial cells promoted the induction of the autophagy related factors such as LC3II, Beclin1, and ATG3. Our results suggest a potential role of miR-Let7A in the autophagy process of microglia during CNS inflammation.
Autophagy* ; Central Nervous System Diseases ; Inflammation ; Microglia* ; MicroRNAs

Repetitive transcranial magnetic stimulation (rTMS) is widely recognized as an effective and noninvasive neuromodulation for treating depression, and has been applied in a wide range of clinical settings. However, previous studies often reported inconsistent antidepressant effects that may be due to differences in the rTMS protocols such as coil placement. The typical simulation site for rTMS depression protocol is the left dorsolateral prefrontal cortex (DLPFC). Targeting the exact site of the left DLPFC while considering individual brain structure has been challenging due to the non-invasive nature of rTMS. Several researchers have applied various targeting methods to overcome the abovementioned issue. Most of the previous studies have applied the “5-cm rule” or the “international 10-20 system,” which is easily applicable. Recently, researchers started to apply a neuronavigation system that targets the stimulation site based on neuroimaging of each individual. Pros and cons of targeting methods have been discussed in terms of validity and reliability of targeting stimulation sites, differences in treatment responses, as well as considerations of individual characteristics. Therefore, the current review focuses on the targeting methods of stimulation site and the treatment effects of depression in previous studies. For discussion, we divided neuronavigation methods into using fixed coordinates and using individualized targets. Furthermore, the limitations of each targeting method are discussed that may potentially contribute to the development of the optimal rTMS protocol for depression treatment.

PURPOSE: To report a suprachoroidal hemorrhage by Valsalva maneuver during vitrectomy under general anesthesia. CASE SUMMARY: A healthy 26-year-old man had vitrectomy under general anesthesia due to rhegmatogenous retinal detachment in his right eye. During scleral indentation and endolaser photocoagulation, he took a sudden and severe bucking reflex because the effect of general anesthesia was insufficient. After the bucking reflex, suprachoroidal hemorrhage occurred in his right eye. Immediate IOP elevation and hyperfluorocarbon tamponade was performed to remove the suprachoroidal hemorrhage and reattach the retina and choroid. The patient's corrected visual acuity was 20/50 and slender crescent shaped choroidal rupture remained around the temporal area of the macula, unlike traumatic choroidal rupture. Following fluorescein angiography, staining was evident at the choroidal rupture site; no fluorescein leakage was evident. CONCLUSIONS: We report a case of acute suprachoroidal hemorrhage which we investigated by fundus examination and fluorescein angiography.
Adult ; Anesthesia, General ; Choroid ; Eye ; Fluorescein ; Fluorescein Angiography ; Hemorrhage ; Humans ; Light Coagulation ; Reflex ; Retina ; Retinal Detachment ; Rupture ; Valsalva Maneuver ; Visual Acuity ; Vitrectomy

PURPOSE: To report central retinal vein and artery occlusion after retrobulbar anesthesia for a cataract operation. CASE SUMMARY: A 65-year-old woman was transferred to our facility 4 days after she had undergone cataract extraction with IOL implantation. She could count fingers and had a relative afferent papillary defect in her left eye. As seen upon fundus examination, dot-shaped, circular-shaped irregular, and partially linear-shaped retinal hemorrhages were evident. Fluorescein angiography revealed that branch arteries around the nasal and temporal areas were not filled, and that the filling of veins was delayed. After two weeks, the patient was only able to recognize hand motion, and her intraocular pressure was 10 mmHg. According to a fundus examination, the size and quantity of retinal hemorrhages increased, and a pale, macular edema was observed. Following fluorescein angiography, the filling defect of branch vessels on the nasal and temporal areas was still evident, and the blocked fluorescence of capillaries on the fundus was prominent. After two months, she could still only recognize hand motion, and her intraocular pressure had increased to 35 mmHg; we therefore diagnosed a neovascular glaucoma. CONCLUSIONS: A patient experienced a serious central retinal vessel occlusion after retrobulbar anesthesia for cataract extraction. Retrobulbar injections should therefore be administered with great caution to prevent this outcome.
Aged ; Anesthesia ; Arteries ; Capillaries ; Cataract ; Cataract Extraction ; Eye ; Female ; Fingers ; Fluorescein Angiography ; Fluorescence ; Glaucoma, Neovascular ; Glycosaminoglycans ; Hand ; Humans ; Intraocular Pressure ; Macular Edema ; Retinal Hemorrhage ; Retinal Vein ; Retinal Vessels ; Veins

PURPOSE: Neural stem cells (NSCs) effectively reverse some severe central nervous system (CNS) disorders, due to their ability to differentiate into neurons. Agmatine, a biogenic amine, has cellular protective effects and contributes to cellular proliferation and differentiation in the CNS. Recent studies have elucidated the function of microRNA let-7a (let-7a) as a regulator of cell differentiation with roles in regulating genes associated with CNS neurogenesis. MATERIALS AND METHODS: This study aimed to investigate whether agmatine modulates the expression of crucial regulators of NSC differentiation including DCX, TLX, c-Myc, and ERK by controlling let-7a expression. RESULTS: Our data suggest that high levels of let-7a promoted the expression of TLX and c-Myc, as well as repressed DCX and ERK expression. In addition, agmatine attenuated expression of TLX and increased expression of ERK by negatively regulating let-7a. CONCLUSION: Our study therefore enhances the present understanding of the therapeutic potential of NSCs in CNS disorders.
Agmatine* ; Biogenic Amines ; Cell Differentiation ; Cell Proliferation ; Central Nervous System ; MicroRNAs* ; Neural Stem Cells* ; Neurogenesis ; Neurons

PURPOSE: Neural stem cells (NSCs) effectively reverse some severe central nervous system (CNS) disorders, due to their ability to differentiate into neurons. Agmatine, a biogenic amine, has cellular protective effects and contributes to cellular proliferation and differentiation in the CNS. Recent studies have elucidated the function of microRNA let-7a (let-7a) as a regulator of cell differentiation with roles in regulating genes associated with CNS neurogenesis. MATERIALS AND METHODS: This study aimed to investigate whether agmatine modulates the expression of crucial regulators of NSC differentiation including DCX, TLX, c-Myc, and ERK by controlling let-7a expression. RESULTS: Our data suggest that high levels of let-7a promoted the expression of TLX and c-Myc, as well as repressed DCX and ERK expression. In addition, agmatine attenuated expression of TLX and increased expression of ERK by negatively regulating let-7a. CONCLUSION: Our study therefore enhances the present understanding of the therapeutic potential of NSCs in CNS disorders.
Agmatine* ; Biogenic Amines ; Cell Differentiation ; Cell Proliferation ; Central Nervous System ; MicroRNAs* ; Neural Stem Cells* ; Neurogenesis ; Neurons