The gut-brain axis is a bidirectional communication pathway connecting the central nervous system and gastrointestinal tract,playing a key role in the occurrence and development of diseases related to this axis.The vermiform appendix,as a part of the gut that is connected to the cecum,has a unique anatomical location,a rich microbiome,and abundant immune cells.Appendicitis and appendectomy have been found to be associated with the development of diseases related to the gut-brain axis.This review first introduces the anatomy and functions of the vermiform appendix and then expounds the associations of appendicitis and appendectomy with diseases related to the gut-brain axis.Furthermore,this review summarizes and prospects the mechanisms of the vermiform appendix in affecting the occurrence and development of diseases related to the gut-brain axis.
Humans ; Appendix/anatomy & histology* ; Brain ; Appendicitis ; Appendectomy/adverse effects* ; Gastrointestinal Microbiome ; Brain-Gut Axis

Humans ; Water ; Rivers ; Skull/anatomy & histology* ; Brain/diagnostic imaging* ; Forensic Medicine ; Forensic Anthropology

BACKGROUND: The sectioned images of a cadaver head made from the Visible Korean project have been used for research and educational purposes. However, the image resolution is insufficient to observe detailed structures suitable for experts. In this study, advanced sectioned images with higher resolution were produced for the identification of more detailed structures. METHODS: The head of a donated female cadaver was scanned for 3 Tesla magnetic resonance images and diffusion tensor images (DTIs). After the head was frozen, the head was sectioned serially at 0.04-mm intervals and photographed repeatedly using a digital camera. RESULTS: On the resulting 4,000 sectioned images (intervals and pixel size, 0.04 mm³; color depth, 48 bits color; a file size, 288 Mbytes), minute brain structures, which can be observed not on previous sectioned images but on microscopic slides, were observed. The voxel size of this study (0.04 mm³) was very minute compared to our previous study (0.1 mm³; resolution, 4,368 × 2,912) and Visible Human Project of the USA (0.33 mm³; resolution, 2,048 × 2,048). Furthermore, the sectioned images were combined with tractography of the DTIs to elucidate the white matter with high resolution and the actual color of the tissue. CONCLUSION: The sectioned images will be used for diverse research, including the applications for the cross sectional anatomy and three-dimensional models for virtual experiments.
Anatomy, Cross-Sectional ; Brain ; Cadaver ; Diffusion ; Diffusion Tensor Imaging ; Female ; Head ; Humans ; White Matter

BACKGROUND: Gross anatomy and sectional anatomy of a monkey should be known by students and researchers of veterinary medicine and medical research. However, materials to learn the anatomy of a monkey are scarce. Thus, the objective of this study was to produce a Visible Monkey data set containing cross sectional images, computed tomographs (CTs), and magnetic resonance images (MRIs) of a monkey whole body. METHODS: Before and after sacrifice, a female rhesus monkey was used for 3 Tesla MRI and CT scanning. The monkey was frozen and sectioned at 0.05 mm intervals for the head region and at 0.5 mm intervals for the rest of the body using a cryomacrotome. Each sectioned surface was photographed using a digital camera to obtain horizontal sectioned images. Segmentation of sectioned images was performed to elaborate three-dimensional (3D) models of the skin and brain. RESULTS: A total of 1,612 horizontal sectioned images of the head and 1,355 images of the remaining region were obtained. The small pixel size (0.024 mm × 0.024 mm) and real color (48 bits color) of these images enabled observations of minute structures. CONCLUSION: Due to small intervals of these images, continuous structures could be traced completely. Moreover, 3D models of the skin and brain could be used for virtual dissections. Sectioned images of this study will enhance the understanding of monkey anatomy and foster further studies. These images will be provided to any requesting researcher free of charge.
Anatomy, Cross-Sectional ; Brain ; Dataset ; Female ; Haplorhini ; Head ; Humans ; Macaca mulatta ; Magnetic Resonance Imaging ; Primates ; Skin ; Tomography, X-Ray Computed ; Veterinary Medicine

Variations of the dural folds and the dural venous sinuses are infrequently reported in the existing medical literature. Such variations in the posterior cranial fossa may pose difficulties in various analytical and surgical procedures of this region. We present a rare concurrent variation of the falx cerebelli and tentorium cerebelli that was detected during routine dissection of an adult male cadaver. While removing the brain, a partial duplication of tentorium cerebelli was observed below the left half of the tentorium cerebelli and above the left cerebellar hemisphere. This fold did not have any dural venous sinus in it. Further, a complete duplication of falx cerebelli with a single occipital venous sinus within its attached border was also observed. We present the review of literature and discuss the comparative anatomy of this case.
Adult ; Anatomy, Comparative ; Brain ; Cadaver ; Cranial Fossa, Posterior ; Dura Mater ; Humans ; Male ; Meninges ; Spinal Cord

The GABAergic neurons in the parafacial zone (PZ) play an important role in sleep-wake regulation and have been identified as part of a sleep-promoting center in the brainstem, but the long-range connections mediating this function remain poorly characterized. Here, we performed whole-brain mapping of both the inputs and outputs of the GABAergic neurons in the PZ of the mouse brain. We used the modified rabies virus EnvA-ΔG-DsRed combined with a Cre/loxP gene-expression strategy to map the direct monosynaptic inputs to the GABAergic neurons in the PZ, and found that they receive inputs mainly from the hypothalamic area, zona incerta, and parasubthalamic nucleus in the hypothalamus; the substantia nigra, pars reticulata and deep mesencephalic nucleus in the midbrain; and the intermediate reticular nucleus and medial vestibular nucleus (parvocellular part) in the pons and medulla. We also mapped the axonal projections of the PZ GABAergic neurons with adeno-associated virus, and defined the reciprocal connections of the PZ GABAergic neurons with their input and output nuclei. The newly-found inputs and outputs of the PZ were also listed compared with the literature. This cell-type-specific neuronal whole-brain mapping of the PZ GABAergic neurons may reveal the circuits underlying various functions such as sleep-wake regulation.
Animals ; Axons ; physiology ; Brain ; anatomy & histology ; Brain Mapping ; Brain Stem ; cytology ; GABAergic Neurons ; physiology ; Green Fluorescent Proteins ; genetics ; metabolism ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Neural Pathways ; physiology ; Peptide Elongation Factor 1 ; genetics ; metabolism ; Rabies virus ; genetics ; metabolism ; Transduction, Genetic ; Vesicular Inhibitory Amino Acid Transport Proteins ; genetics ; metabolism

The striatum and globus pallidus are principal nuclei of the basal ganglia. Nissl- and acetylcholinesterase-stained sections of the tree shrew brain showed the neuroanatomical features of the caudate nucleus (Cd), internal capsule (ic), putamen (Pu), accumbens, internal globus pallidus, and external globus pallidus. The ic separated the dorsal striatum into the Cd and Pu in the tree shrew, but not in rats and mice. In addition, computer-based 3D images allowed a better understanding of the position and orientation of these structures. These data provided a large-scale atlas of the striatum and globus pallidus in the coronal, sagittal, and horizontal planes, the first detailed distribution of parvalbumin-immunoreactive cells in the tree shrew, and the differences in morphological characteristics and density of parvalbumin-immunoreactive neurons between tree shrew and rat. Our findings support the tree shrew as a potential model for human striatal disorders.
Acetylcholinesterase ; metabolism ; Animals ; Brain Mapping ; Corpus Striatum ; anatomy & histology ; cytology ; metabolism ; Globus Pallidus ; anatomy & histology ; cytology ; metabolism ; Imaging, Three-Dimensional ; Male ; Mice ; Mice, Inbred C57BL ; Models, Neurological ; Neurons ; metabolism ; Parvalbumins ; metabolism ; Rats ; Rats, Sprague-Dawley ; Statistics, Nonparametric ; Tupaiidae ; anatomy & histology

Diffusion-weighted magnetic resonance imaging (dMRI) is widely used to study white and gray matter (GM) micro-organization and structural connectivity in the brain. Super-resolution track-density imaging (TDI) is an image reconstruction method for dMRI data, which is capable of providing spatial resolution beyond the acquired data, as well as novel and meaningful anatomical contrast that cannot be obtained with conventional reconstruction methods. TDI has been used to reveal anatomical features in human and animal brains. In this study, we used short track TDI (stTDI), a variation of TDI with enhanced contrast for GM structures, to reconstruct direction-encoded color maps of fixed tree shrew brain. The results were compared with those obtained with the traditional diffusion tensor imaging (DTI) method. We demonstrated that fine microstructures in the tree shrew brain, such as Baillarger bands in the primary visual cortex and the longitudinal component of the mossy fibers within the hippocampal CA3 subfield, were observable with stTDI, but not with DTI reconstructions from the same dMRI data. The possible mechanisms underlying the enhanced GM contrast are discussed.
Animals ; Brain Mapping ; Diffusion Tensor Imaging ; methods ; Hippocampus ; diagnostic imaging ; Image Processing, Computer-Assisted ; methods ; Male ; Neural Pathways ; diagnostic imaging ; Tupaiidae ; anatomy & histology ; Visual Cortex ; diagnostic imaging

We report the case of a giant hypothalamic hamartoma with a large intracranial cyst in a neonate. On ultrasonography, the lesion presented as a lobulated, mass-like lesion with similar echogenicity to the adjacent brain parenchyma, located anterior to the underdeveloped and compressed left temporal lobe, and presenting as an intracranial cyst in the left cerebral convexity without definite internal echogenicity or septa. The presence of a hypothalamic hamartoma and intracranial neurenteric cyst were confirmed by surgical biopsy. The association of a giant hypothalamic hamartoma and a neurenteric cyst is rare. Due to the rarity of this association, the large size of the intracranial cyst, and the resulting distortion in the regional anatomy, the diagnosis of the solid mass was not made correctly on prenatal high-resolution ultrasonography.
Anatomy, Regional ; Biopsy ; Brain ; Central Nervous System Cysts ; Diagnosis ; Hamartoma* ; Humans ; Infant, Newborn* ; Magnetic Resonance Imaging ; Neural Tube Defects ; Temporal Lobe ; Ultrasonography

We propose a multi-weighted probabilistic atlas to obtain accurate, robust, and reliable segmentation. The local similarity measure is used as the weight to compute the probabilistic atlas, and the distance field is used as the weight to incorporate the locality information of the atlas; the self-similarity is used as the weight to incorporate the local information of target image to refine the probabilistic atlas. Experimental results with brain MRI images showed that the proposed algorithm outperforms the common brain image segmentation methods and achieved a median Dice coefficient of 87.1% on the left hippocampus and 87.6% on the right.
Algorithms ; Brain ; anatomy & histology ; Humans ; Magnetic Resonance Imaging ; Neuroimaging