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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 -
Frontiers in Immunology 2023Encephalitis is a devastating neurologic disorder with high morbidity and mortality. Autoimmune causes are roughly as common as infectious ones. N-methyl-D-aspartic acid...
BACKGROUND AND OBJECTIVES
Encephalitis is a devastating neurologic disorder with high morbidity and mortality. Autoimmune causes are roughly as common as infectious ones. N-methyl-D-aspartic acid receptor (NMDAR) encephalitis (NMDARE), characterized by serum and/or spinal fluid NMDAR antibodies, is the most common form of autoimmune encephalitis (AE). A translational rodent NMDARE model would allow for pathophysiologic studies of AE, leading to advances in the diagnosis and treatment of this debilitating neuropsychiatric disorder. The main objective of this work was to identify optimal active immunization conditions for NMDARE in mice.
METHODS
Female C57BL/6J mice aged 8 weeks old were injected subcutaneously with an emulsion of complete Freund's adjuvant, killed and dessicated , and a 30 amino acid peptide flanking the NMDAR GluN1 subunit N368/G369 residue targeted by NMDARE patients' antibodies. Three different induction methods were examined using subcutaneous injection of the peptide emulsion mixture into mice in 1) the ventral surface, 2) the dorsal surface, or 3) the dorsal surface with reimmunization at 4 and 8 weeks (boosted). Mice were bled biweekly and sacrificed at 2, 4, 6, 8, and 14 weeks. Serum and CSF NMDAR antibody titer, mouse behavior, hippocampal cell surface and postsynaptic NMDAR cluster density, and brain immune cell entry and cytokine content were examined.
RESULTS
All immunized mice produced serum and CSF NMDAR antibodies, which peaked at 6 weeks in the serum and at 6 (ventral and dorsal boosted) or 8 weeks (dorsal unboosted) post-immunization in the CSF, and demonstrated decreased hippocampal NMDAR cluster density by 6 weeks post-immunization. In contrast to dorsally-immunized mice, ventrally-induced mice displayed a translationally-relevant phenotype including memory deficits and depressive behavior, changes in cerebral cytokines, and entry of T-cells into the brain at the 4-week timepoint. A similar phenotype of memory dysfunction and anxiety was seen in dorsally-immunized mice only when they were serially boosted, which also resulted in higher antibody titers.
DISCUSSION
Our study revealed induction method-dependent differences in active immunization mouse models of NMDARE disease. A novel ventrally-induced NMDARE model demonstrated characteristics of AE earlier compared to dorsally-induced animals and is likely suitable for most short-term studies. However, boosting and improving the durability of the immune response might be preferred in prolonged longitudinal studies.
Topics: Mice; Female; Animals; Emulsions; Mice, Inbred C57BL; Encephalitis; Antibodies; Receptors, N-Methyl-D-Aspartate; Vaccination; Disease Models, Animal; Autoimmune Diseases of the Nervous System
PubMed: 37520559
DOI: 10.3389/fimmu.2023.1177672 -
Journal of Ayub Medical College,... 2023Incarcerated gravid uterus for in ventral hernia is an extremely rare obstetrical and surgical problem which contributes to pregnancy related complications. We searched... (Review)
Review
Incarcerated gravid uterus for in ventral hernia is an extremely rare obstetrical and surgical problem which contributes to pregnancy related complications. We searched for literature to identify aetiology, presentation, complications, and management options for incarcerated gravid uterus, and are presenting this case with literature review. This extremely rare case report, first ever from Pakistan, of an incisional hernia containing gravid uterus as its contents and is bulging out of abdominal cavity. She presented at 27 weeks with ulceration of ventral hernia skin. She was offered a conservative treatment keeping in view maternal and foetal monitoring until term. A full-term elective lower segment caesarean section (LSCS) followed by open mesh repair was done. A successful outcome was observed. There are limited treatment options for uterine incarceration into ventral hernia, but definitive diagnosis allows procedures to treat and to reduce severe maternal and foetal complications. There is no consensus over the management of this rare condition. A tailor approach should be opted in each case. If uncomplicated, a conservative approach until term followed by delivery or LSCS and hernioplasty is a good option.
Topics: Female; Humans; Pregnancy; Cesarean Section; Hernia, Ventral; Incisional Hernia; Obstetrics; Uterus
PubMed: 36849402
DOI: 10.55519/JAMC-01-11054 -
Surgical Neurology International 2021The epidural ligaments (ELs) (of Hofmann) were described as fibrous bands interconnecting the ventrolateral spinal dura and the posterior longitudinal ligament below L1.... (Review)
Review
BACKGROUND
The epidural ligaments (ELs) (of Hofmann) were described as fibrous bands interconnecting the ventrolateral spinal dura and the posterior longitudinal ligament below L1. They are hardly ever discussed in the literature or considered in hypothesis-driven basic science experiments or spine biomechanical models.
METHODS
Intraoperative photographs were obtained to illustrate a group of posterolateral spinal ELs. In addition, electronic database searches (PubMed, Ovid Embase, and SCOPUS) were utilized to summarize the anatomy, and relevant clinical and surgical factors impacting these ELs.
RESULTS
ELs attach circumferentially at most spinal levels. They anchor the nerve root sleeves ventrally, and therefore, may play a role in the some idiopathic neurologic deficits (e.g., postoperative radiculopathies, C5 palsies) in patients without radiological compression. The posterolateral ELs originate on the dura dorsal to the nerve root sleeves and insert on the ipsilateral lamina, interlaminar ligament, and facet capsule. They appear to be continuous with the peridural membrane, a fibrovascular sheath that surrounds the thecal sac and serves as a scaffold for the internal vertebral venous plexus of Batson and epidural fat.
CONCLUSION
The spinal ELs should be divided sharply during surgery to prevent durotomies, especially in patients with advanced spondylosis and facet arthropathy. Disconnecting these ligaments releases the thecal sac laterally and ventrally, allowing for medial mobilization when performing discectomies or for working in the ventral epidural space.
PubMed: 33598349
DOI: 10.25259/SNI_894_2020 -
Cerebral Cortex Communications 2023Despite their anatomical and functional distinctions, there is growing evidence that the dorsal and ventral visual pathways interact to support object recognition....
Despite their anatomical and functional distinctions, there is growing evidence that the dorsal and ventral visual pathways interact to support object recognition. However, the exact nature of these interactions remains poorly understood. Is the presence of identity-relevant object information in the dorsal pathway simply a byproduct of ventral input? Or, might the dorsal pathway be a source of input to the ventral pathway for object recognition? In the current study, we used high-density EEG-a technique with high temporal precision and spatial resolution sufficient to distinguish parietal and temporal lobes-to characterise the dynamics of dorsal and ventral pathways during object viewing. Using multivariate analyses, we found that category decoding in the dorsal pathway preceded that in the ventral pathway. Importantly, the dorsal pathway predicted the multivariate responses of the ventral pathway in a time-dependent manner, rather than the other way around. Together, these findings suggest that the dorsal pathway is a critical source of input to the ventral pathway for object recognition.
PubMed: 36726794
DOI: 10.1093/texcom/tgad003 -
Molecular Psychiatry Dec 2023Adult neurogenesis is reduced during aging and impaired in disorders of stress, memory, and cognition though its normal function remains unclear. Moreover, a systems...
Adult neurogenesis is reduced during aging and impaired in disorders of stress, memory, and cognition though its normal function remains unclear. Moreover, a systems level understanding of how a small number of young hippocampal neurons could dramatically influence brain function is lacking. We examined whether adult neurogenesis sustains hippocampal connections cumulatively across the life span. Long-term suppression of neurogenesis as occurs during stress and aging resulted in an accelerated decline in hippocampal acetylcholine signaling and a slow and progressing emergence of profound working memory deficits. These deficits were accompanied by compensatory reorganization of cholinergic dentate gyrus inputs with increased cholinergic innervation to the ventral hippocampus and recruitment of ventrally projecting neurons by the dorsal projection. While increased cholinergic innervation was dysfunctional and corresponded to overall decreases in cholinergic levels and signaling, it could be recruited to correct the resulting memory dysfunction even in old animals. Our study demonstrates that hippocampal neurogenesis supports memory by maintaining the septohippocampal cholinergic circuit across the lifespan. It also provides a systems level explanation for the progressive nature of memory deterioration during normal and pathological aging and indicates that the brain connectome is malleable by experience.
Topics: Animals; Hippocampus; Neurogenesis; Aging; Memory, Short-Term; Male; Cholinergic Neurons; Acetylcholine; Neurons; Mice; Mice, Inbred C57BL; Memory Disorders; Dentate Gyrus
PubMed: 37479778
DOI: 10.1038/s41380-023-02167-z -
Advances in Surgery Sep 2019
Review
Topics: Hernia, Ventral; Herniorrhaphy; Laparoscopy; Patient Selection; Surgical Mesh
PubMed: 31327439
DOI: 10.1016/j.yasu.2019.04.001 -
Surgery Mar 2021Ventral hernia repair is a common procedure with reported 15% to 37% morbidity and 0.3% to 1.4% mortality rates. This study examines the 30-day morbidity and mortality...
BACKGROUND
Ventral hernia repair is a common procedure with reported 15% to 37% morbidity and 0.3% to 1.4% mortality rates. This study examines the 30-day morbidity and mortality of open and laparoscopic ventral hernia repair in veterans, along with the impact of body mass index on these outcomes.
METHODS
The Veterans Affairs Surgical Quality Improvement Program was queried for all ventral hernia repairs during the period 2008 to 2015. In this retrospective analysis, we compared outcomes of open ventral hernia repair versus laparoscopic ventral hernia repair and among different body mass index classes.
RESULTS
A total of 19,883 patients were identified (92.6% male, mean age 59.7, 53.1% obese, and 71.6% with American Society of Anesthesiologists class ≥III). There were 95 (0.5%) mortalities, and complications occurred in 1,289 (6.5%) patients. Open ventral hernia repair was performed in 60.2%; 14.5% were recurrent, and 3.3% were performed as an emergency operation. When compared with open ventral hernia repair, the laparoscopic ventral hernia repair group had higher mean body mass index, less patients with American Society of Anesthesiologists class ≥III, fewer emergency operations, longer operative time, less complications, decreased mortality, and shorter duration of stay. Body mass index 35.00 to 49.99 was predictive of overall complications in the open ventral hernia repair group.
CONCLUSION
Ventral hernia repair can be performed in the veteran population with outcomes comparable to those in the private sector. Morbid obesity has a negative impact on ventral hernia repair outcomes that is most prominent following open surgery. Laparoscopic ventral hernia repair may offer superior outcomes when compared to open ventral hernia repair and may be considered.
Topics: Adult; Aged; Body Mass Index; Comorbidity; Female; Hernia, Ventral; Herniorrhaphy; Humans; Male; Middle Aged; Morbidity; Operative Time; Preoperative Care; Risk Factors; Treatment Outcome; Veterans; Veterans Health Services
PubMed: 33077198
DOI: 10.1016/j.surg.2020.09.003 -
Zoology (Jena, Germany) Aug 2022Sexual dimorphism in snakes is generally described in association with body or tail size and scale counts, with relatively few studies addressing intrasexual divergence...
Sexual dimorphism in snakes is generally described in association with body or tail size and scale counts, with relatively few studies addressing intrasexual divergence in the skull. Here, we analyzed sexual dimorphism in the size and shape of skull and body in three malacophagous dipsadine snakes, Dipsas mikanii, Dipsas neuwiedi and Dipsas turgida, as well as allometric effect on these components. We used linear and geometric analysis to assess: (1) if there is sexual dimorphism in cranial components; (2) if there are differences between the sexes regarding body and tail size, number of ventral and subcaudal scales; (3) whether there is covariation between cranial components and body size; (4) if there are changes in cranial shape associated with increased size; and (5) whether there is an allometric relationship between body and tail size. Our results showed that all three species are dimorphic in cranial shape and size (except D. turgida for cranial size), with females having longer and thinner skulls than males. In the three species, the female skull was negatively allometric, whereas the male skull was isometric. Allometry related to cranial shape was significant only in males of D. turgida, which showed greater snout robustness and eye size associated with enlargement of the skull. Females of D. mikanii and D. neuwiedi were significantly larger than males. Only males of D. neuwiedi showed positive allometry for the tail, while dimorphism related to scale counts followed the pattern found in most snakes, with females having a greater number of ventrals and males subcaudals (except D. neuwiedi in the latter case). Based on our results, we hypothesize that patterns of sexual dimorphism and skull allometry in malacophagous snakes may be explained both by aspects related to diet and reproduction. Meanwhile, patterns associated with body size reflect advantages related to fecundity favoring greater reproductive success of females.
Topics: Animals; Body Size; Female; Head; Male; Sex Characteristics; Skull; Snakes
PubMed: 35759990
DOI: 10.1016/j.zool.2022.126026