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The Journal of Comparative Neurology Dec 2023Accurate anatomical characterizations are necessary to investigate neural circuitry on a fine scale, but for the rodent claustrum complex (CLCX), this has yet to be...
Accurate anatomical characterizations are necessary to investigate neural circuitry on a fine scale, but for the rodent claustrum complex (CLCX), this has yet to be fully accomplished. The CLCX is generally considered to comprise two major subdivisions, the claustrum (CL) and the dorsal endopiriform nucleus (DEn), but regional boundaries to these areas are debated. To address this, we conducted a multifaceted analysis of fiber- and cytoarchitecture, genetic marker expression, and connectivity using mice of both sexes, to create a comprehensive guide for identifying and delineating borders to CLCX, including an online reference atlas. Our data indicated four distinct subregions within CLCX, subdividing both CL and DEn into two. Additionally, we conducted brain-wide tracing of inputs to CLCX using a transgenic mouse line. Immunohistochemical staining against myelin basic protein (MBP), parvalbumin (PV), and calbindin (CB) revealed intricate fiber-architectural patterns enabling precise delineations of CLCX and its subregions. Myelinated fibers were abundant dorsally in CL but absent ventrally, whereas PV expressing fibers occupied the entire CL. CB staining revealed a central gap within CL, also visible anterior to the striatum. The Nr2f2, Npsr1, and Cplx3 genes expressed specifically within different subregions of the CLCX, and Rprm helped delineate the CL-insular border. Furthermore, cells in CL projecting to the retrosplenial cortex were located within the myelin sparse area. By combining own experimental data with digitally available datasets of gene expression and input connectivity, we could demonstrate that the proposed delineation scheme allows anchoring of datasets from different origins to a common reference framework.
Topics: Male; Female; Mice; Animals; Claustrum; Calbindins; Brain; Parvalbumins; Rodentia; Nerve Tissue Proteins; Adaptor Proteins, Signal Transducing
PubMed: 37782702
DOI: 10.1002/cne.25539 -
Eplasty 2023Dorsal augmentation is one of the more complication-prone procedures in rhinoplasty, demanding ample skill and experience to produce an aesthetic and functional result.... (Review)
Review
BACKGROUND
Dorsal augmentation is one of the more complication-prone procedures in rhinoplasty, demanding ample skill and experience to produce an aesthetic and functional result. Numerous autologous grafts, allografts, xenografts, and alloplastic materials have been attempted for augmentation with varying success. Each graft material has its own unique properties that require varying surgical intricacies. The relative risks and benefits of these strategies and materials are also variable and must be weighed. Alloplastic implants are commonly used in eastern countries, but, due to different patient populations and complication profiles, have found less acceptance among western surgeons.
METHODS
A PubMed search was done using the terms "dorsal augmentation rhinoplasty," "liquid rhinoplasty," and "grafts used for rhinoplasty." Publication dates ranging from 1957-2022 were included. Abstracts were screened for relevance, and references from each article were reviewed to identify further articles. Chapters on dorsal augmentation from two key rhinoplasty textbooks were also reviewed.
RESULTS
A total of 79 articles and 2 textbooks were formally screened; of these, 65 resources were included. Findings were grouped under the headings "facial analysis," "ethnic factors in graft selection," "graft characteristics," "septal cartilage," "auricular cartilage," "costal cartilage," "diced cartilage grafts," "bone grafts," "soft tissue grafts," "nonsurgical/liquid rhinoplasty," and "alloplastic implants."
CONCLUSIONS
Current dorsal augmentation literature focuses on retrospective studies and expert experiences. There are limited quantitative and prospective studies present to delineate an ideal graft. With consistently advancing technology and knowledge of facial aesthetics, a surgeon must maintain a thorough understanding of the current graft and implant options to offer a specialized treatment plan for each deformity and patient.
PubMed: 36817363
DOI: No ID Found -
Current Biology : CB Nov 2023The elephant trunk operates as a muscular hydrostat and is actuated by the most complex musculature known in animals. Because the number of trunk muscles is unclear, we...
The elephant trunk operates as a muscular hydrostat and is actuated by the most complex musculature known in animals. Because the number of trunk muscles is unclear, we performed dense reconstructions of trunk muscle fascicles, elementary muscle units, from microCT scans of an Asian baby elephant trunk. Muscle architecture changes markedly across the trunk. Trunk tip and finger consist of about 8,000 extraordinarily filigree fascicles. The dexterous finger consists exclusively of microscopic radial fascicles pointing to a role of muscle miniaturization in elephant dexterity. Radial fascicles also predominate (at 82% volume) the remainder of the trunk tip, and we wonder if radial muscle fascicles are of particular significance for fine motor control of the dexterous trunk tip. By volume, trunk-shaft muscles comprise one-third of the numerous, small radial muscle fascicles; two-thirds of the three subtypes of large longitudinal fascicles (dorsal longitudinals, ventral outer obliques, and ventral inner obliques); and a small fraction of transversal fascicles. Shaft musculature is laterally, but not radially, symmetric. A predominance of dorsal over ventral radial muscles and of ventral over dorsal longitudinal muscles may result in a larger ability of the shaft to extend dorsally than ventrally and to bend inward rather than outward. There are around 90,000 trunk muscle fascicles. While primate hand control is based on fine control of contraction by the convergence of many motor neurons on a small set of relatively large muscles, evolution of elephant grasping has led to thousands of microscopic fascicles, which probably outnumber facial motor neurons.
Topics: Animals; Elephants; Muscle, Skeletal; Motor Neurons
PubMed: 37757829
DOI: 10.1016/j.cub.2023.09.007 -
Veterinary Surgery : VS Feb 2023To investigate the feasibility and describe the clinical experience of performing laryngeal tie-forward (LTF) in standing horses unaffected (experimental) and affected...
OBJECTIVES
To investigate the feasibility and describe the clinical experience of performing laryngeal tie-forward (LTF) in standing horses unaffected (experimental) and affected (clinical) by intermittent dorsal displacement of the soft palate (iDDSP).
STUDY DESIGN
Experimental study and case series.
ANIMALS
Five normal experimental controls and five client owned horses affected by iDDSP.
METHODS
Standing LTF was performed and evaluated in five experimental horses and five clinical cases diagnosed with iDDSP. Standing LTF was performed under endoscopic guidance with horses sedated and the surgical site desensitized with local anesthetic solution. Short term outcome was assessed using radiography, resting and (in clinical cases) dynamic upper respiratory tract (URT) endoscopy.
RESULTS
Standing LTF was well tolerated and completed in all horses. Radiographic assessment demonstrated that compared to preoperatively, the basihyoid bone and thyrohyoid-thyroid articulation were positioned dorsally (9.6 mm, p = .006 and 20.4 mm, p = .007, respectively) at 2 days postoperatively. During repeat dynamic URT endoscopy at 48 hours postoperatively, 3/5 horses showed resolution of iDDSP and 2/5 marked improvement. One horse experienced brief iDDSP associated with neck flexion which corrected after swallowing. The second achieved a greater speed and total distance prior to iDDSP.
CONCLUSIONS
Standing LTF did not incur any major peri- or postoperative complications. The laryngohyoid apparatus was repositioned dorsally and in a small case series had a similar surgical effect on laryngeal position.
CLINICAL SIGNIFICANCE
Standing LTF is feasible, mitigates the risk of general anesthesia related complications and reduces cost.
Topics: Horses; Animals; Larynx; Palate, Soft; Endoscopy; Nose; Radiography; Horse Diseases
PubMed: 36448601
DOI: 10.1111/vsu.13920 -
Frontiers in Human Neuroscience 2022Visual functions of the dorsal stream are considered vulnerable in children with early brain damage. Considering the recognition of objects in suboptimal representations...
AIM
Visual functions of the dorsal stream are considered vulnerable in children with early brain damage. Considering the recognition of objects in suboptimal representations a dorsal stream dysfunction, we examined whether children with early brain damage and impaired object recognition had either general or selective dorsal stream dysfunctions.
METHOD
In a group of children with early brain damage ( = 48) we evaluated the dorsal stream functioning. To determine whether these patients had an increased risk of a dorsal stream dysfunction we compared the percentage of patients with impaired object recognition, assessed with the L94, with the estimated base rate. Then we evaluated the performance levels on motion perception, visual attention and visuomotor tasks in patients with ( = 18) and without ( = 11) object recognition abnormalities. A general dorsal stream dysfunction was considered present if a patient showed at least one abnormally low score in two out of three additional dorsal stream functions.
RESULTS
Six of the eighteen (33.3%) patients with object recognition problems scored abnormally low on at least two additional dorsal stream functions. This was significantly higher than the base rate ( = 0.01). The difference of 24.1% between the patients with and without object recognition problems was not significant. Of the patients with object recognition problems 72.2% had at least 1 dorsal weakness, whereas this was only the case in 27.3% of patients without object recognition problems. Compared to patients with normal object recognition, patients with object recognition problems scored significantly more abnormally low on motion perception and visual attention (s = 0.03) but did not differ on visuomotor skills.
CONCLUSION
Children with object recognition problems seem at risk for other dorsal stream dysfunctions, but dysfunctions might be rather specific than general. Multiple functions/aspects should be evaluated in neuropsychological assessment of children at risk.
PubMed: 35634210
DOI: 10.3389/fnhum.2022.733055 -
Ugeskrift For Laeger Sep 2019
PubMed: 31566177
DOI: No ID Found -
Ugeskrift For Laeger Aug 2019
PubMed: 31495362
DOI: No ID Found -
Faculty Reviews 2022The vertebrate neural tube is a representative example of a morphogen-patterned tissue that generates different cell types with spatial and temporal precision. More... (Review)
Review
The vertebrate neural tube is a representative example of a morphogen-patterned tissue that generates different cell types with spatial and temporal precision. More specifically, the development of the dorsal region of the neural tube is of particular interest because of its highly dynamic behavior. First, early premigratory neural crest progenitors undergo an epithelial-to-mesenchymal transition, exit the neural primordium, and generate, among many derivatives, most of the peripheral nervous system. Subsequently, the dorsal neural tube becomes populated by definitive roof plate cells that constitute an organizing center for dorsal interneurons and guide axonal patterning. In turn, roof plate cells transform into dorsal radial glia that contributes to and shapes the formation of the dorsal ependyma of the central nervous system. To form a normal functional spinal cord, these extraordinary transitions should be tightly regulated in time and space. Thus far, the underlying cellular changes and molecular mechanisms are only beginning to be uncovered. In this review, we discuss recent results that shed light on the end of neural crest production and delamination, the early formation of the definitive roof plate, and its further maturation into radial glia. The last of these processes culminate in the formation of the dorsal ependyma, a component of the stem cell niche of the central nervous system. We highlight how similar mechanisms operate throughout these transitions, which may serve to reveal common design principles applicable to the ontogeny of epithelial tissues.
PubMed: 36225209
DOI: 10.12703/r/11-27 -
Biology Open Sep 2021The tracheal basal cells (BCs) function as stem cells to maintain the epithelium in steady state and repair it after injury. The airway is surrounded by cartilage...
The tracheal basal cells (BCs) function as stem cells to maintain the epithelium in steady state and repair it after injury. The airway is surrounded by cartilage ventrolaterally and smooth muscle dorsally. Lineage tracing using Krt5-CreER shows dorsal BCs produce more, larger, clones than ventral BCs. Large clones were found between cartilage and smooth muscle where subpopulation of dorsal BCs exists. Three-dimensional organoid culture of BCs demonstrated that dorsal BCs show higher colony forming efficacy to ventral BCs. Gene ontology analysis revealed that genes expressed in dorsal BCs are enriched in wound healing while ventral BCs are enriched in response to external stimulus and immune response. Significantly, ventral BCs express Myostatin, which inhibits the growth of smooth muscle cells, and HGF, which facilitates cartilage repair. The results support the hypothesis that BCs from the dorso-ventral airways have intrinsic molecular and behavioural differences relevant to their in vivo function.
Topics: Cell Differentiation; Epithelial Cells; Gene Ontology; Genetic Heterogeneity; Humans; Stem Cells; Trachea
PubMed: 34396394
DOI: 10.1242/bio.058676