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ENeuro Apr 2024Attending to salient sensory attributes of food, such as tastes that are new, displeasing, or unexpected, allows the procurement of nutrients without food poisoning....
Attending to salient sensory attributes of food, such as tastes that are new, displeasing, or unexpected, allows the procurement of nutrients without food poisoning. Exposure to new tastes is known to increase norepinephrine (NE) release in taste processing forebrain areas, yet the central source for this release is unknown. Locus ceruleus norepinephrine neurons (LC-NE) emerge as a candidate in signaling salient information about taste, as other salient sensory stimuli (e.g., visual, auditory, somatosensation) are known to activate LC neurons. To determine if LC neurons are sensitive to features of taste novelty, we used fiber photometry to record LC-NE activity in water-restricted mice that voluntarily licked either novel or familiar substances of differential palatability (saccharine, citric acid). We observed that LC-NE activity was suppressed during lick bursts and transiently activated upon the termination of licking and that these dynamics were independent of the familiarity of the substance consumed. We next recorded LC dynamics during brief and unexpected consumption of tastants and found no increase in LC-NE activity, despite their responsiveness to visual and auditory stimuli, revealing selectivity in LC's responses to salient sensory information. Our findings suggest that LC activity during licking is not influenced by taste novelty, implicating a possible role for non-LC noradrenergic nuclei in signaling critical information about taste.
Topics: Animals; Locus Coeruleus; Male; Mice, Inbred C57BL; Norepinephrine; Taste; Mice; Taste Perception; Citric Acid; Saccharin; Neurons; Female; Behavior, Animal
PubMed: 38649278
DOI: 10.1523/ENEURO.0535-23.2024 -
Sichuan Da Xue Xue Bao. Yi Xue Ban =... Mar 2024To study the microanatomic structure of the subtemporal transtentorial approach to the lateral side of the brainstem, and to provide anatomical information that will...
OBJECTIVE
To study the microanatomic structure of the subtemporal transtentorial approach to the lateral side of the brainstem, and to provide anatomical information that will assist clinicians to perform surgeries on the lateral, circumferential, and petroclival regions of the brainstem.
METHODS
Anatomical investigations were conducted on 8 cadaveric head specimens (16 sides) using the infratemporal transtentorial approach. The heads were tilted to one side, with the zygomatic arch at its highest point. Then, a horseshoe incision was made above the auricle. The incision extended from the midpoint of the zygomatic arch to one third of the mesolateral length of the transverse sinus, with the flap turned towards the temporal part. After removing the bone, the arachnoid and the soft meninges were carefully stripped under the microscope. The exposure range of the surgical approach was observed and the positional relationships of relevant nerves and blood vessels in the approach were clarified. Important structures were photographed and the relevant parameters were measured.
RESULTS
The upper edge of the zygomatic arch root could be used to accurately locate the base of the middle cranial fossa. The average distances of the star point to the apex of mastoid, the star point to the superior ridge of external auditory canal, the anterior angle of parietomastoid suture to the superior ridge of external auditory canal, and the anterior angle of parietomastoid suture to the star point of the 10 adult skull specimens were 47.23 mm, 45.27 mm, 26.16 mm, and 23.08 mm, respectively. The subtemporal approach could fully expose the area from as high as the posterior clinoid process to as low as the petrous ridge and the arcuate protuberance after cutting through the cerebellar tentorium. The approach makes it possible to handle lesions on the ventral or lateral sides of the middle clivus, the cistern ambiens, the midbrain, midbrain, and pons. In addition, the approach can significantly expand the exposure area of the upper part of the tentorium cerebelli through cheekbone excision and expand the exposure range of the lower part of the tentorium cerebelli through rock bone grinding technology. The total length of the trochlear nerve, distance of the trochlear nerve to the tentorial edge of cerebellum, length of its shape in the tentorial mezzanine, and its lower part of entering into the tentorium cerebelli to the petrosal ridge were (16.95±4.74) mm, (1.27±0.73) mm, (5.72±1.37) mm, and (4.51±0.39) mm, respectively. The cerebellar tentorium could be safely opened through the posterior clinoid process or arcuate protrusion for localization. The oculomotor nerve could serve as an anatomical landmark to locate the posterior cerebral artery and superior cerebellar artery.
CONCLUSION
Through microanatomic investigation, the exposure range and intraoperative difficulties of the infratemporal transtentorial approach can be clarified, which facilitates clinicians to accurately and safely plan surgical methods and reduce surgical complications.
Topics: Humans; Cadaver; Brain Stem; Temporal Bone; Cranial Fossa, Middle; Craniotomy
PubMed: 38645855
DOI: 10.12182/20240360506 -
Vaccine May 2024Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) vaccines have been long overdue. Structure-based vaccine design created a new momentum in the last...
Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) vaccines have been long overdue. Structure-based vaccine design created a new momentum in the last decade, and the first RSV vaccines have finally been approved in older adults and pregnant individuals. These vaccines are based on recombinant stabilized pre-fusion F glycoproteins administered as soluble proteins. Multimeric antigenic display could markedly improve immunogenicity and should be evaluated in the next generations of vaccines. Here we tested a new virus like particles-based vaccine platform which utilizes the direct fusion of an immunogen of interest to the structural human immunodeficient virus (HIV) protein Gag to increase its surface density and immunogenicity. We compared, in mice, the immunogenicity of RSV-F or hMPV-F based immunogens delivered either as soluble proteins or displayed on the surface of our VLPs. VLP associated F-proteins showed better immunogenicity and induced superior neutralizing responses. Moreover, when combining both VLP associated and soluble immunogens in a heterologous regimen, VLP-associated immunogens provided added benefits when administered as the prime immunization.
Topics: Animals; Antibodies, Neutralizing; Mice; Metapneumovirus; Vaccines, Virus-Like Particle; Female; Viral Fusion Proteins; Antibodies, Viral; Mice, Inbred BALB C; gag Gene Products, Human Immunodeficiency Virus; Respiratory Syncytial Virus, Human; Immunogenicity, Vaccine; Humans; Respiratory Syncytial Virus Vaccines; Recombinant Fusion Proteins; Respiratory Syncytial Virus Infections; Viral Vaccines
PubMed: 38641492
DOI: 10.1016/j.vaccine.2024.04.048 -
Journal of Parkinson's Disease 2024Rapid eye movement sleep behavior disorder (RBD) may precede or follow motor symptoms in Parkinson's disease (PD). While over 70% of idiopathic RBD cases phenoconvert...
BACKGROUND
Rapid eye movement sleep behavior disorder (RBD) may precede or follow motor symptoms in Parkinson's disease (PD). While over 70% of idiopathic RBD cases phenoconvert within a decade, a small subset develops PD after a more extended period or remains nonconverted. These heterogeneous manifestations of RBD in PD prompt subtype investigations. Premotor RBD may signify "body-first" PD with bottom-up, symmetric synucleinopathy propagation.
OBJECTIVE
Explore brainstem and nigrostriatal monoaminergic degeneration pattern differences based on premotor RBD presence and duration in de novo PD patients.
METHODS
In a cross-sectional analysis of de novo PD patients (n = 150) undergoing FP-CIT PET and RBD Single-Question Screen, the cohort was categorized into groups with and without premotor RBD (PDRBD +/-), with further classification of PDRBD + based on a 10-year duration of premotor RBD. Analysis of FP-CIT binding in the striatum and pons, striatal asymmetry, and striatum-to-pons ratios compared patterns of nigrostriatal and brainstem monoaminergic degeneration.
RESULTS
PDRBD + exhibited more severe and symmetrical striatal dopaminergic denervation compared to PDRBD-, with the difference in severity accentuated in the least-affected hemisphere. The PDRBD +<10Y subgroup displayed the most prominent striatal symmetry, supporting a more homogeneous "body-first" subtype. Pontine uptakes remained lower in PDRBD + even after adjusting for striatal uptake, suggesting early degeneration of pontine monoaminergic nuclei.
CONCLUSIONS
Premotor RBD in PD is associated with severe, symmetrical nigrostriatal and brainstem monoaminergic degeneration, especially in cases with PD onset within 10 years of RBD. This supports the concept of a "widespread, bottom-up" pathophysiological mechanism associated with premotor RBD in PD.
Topics: Humans; REM Sleep Behavior Disorder; Parkinson Disease; Male; Aged; Female; Middle Aged; Cross-Sectional Studies; Positron-Emission Tomography; Corpus Striatum; Brain Stem; Tropanes; Substantia Nigra
PubMed: 38640171
DOI: 10.3233/JPD-230459 -
Saudi Journal of Ophthalmology :... 2024Multiple sclerosis (MS) is the most common demyelinating disease affecting the central nervous system. It has a wide range of manifestations and commonly affects the...
Multiple sclerosis (MS) is the most common demyelinating disease affecting the central nervous system. It has a wide range of manifestations and commonly affects the visual system. Many patients with MS report decreased vision, diplopia, nystagmus, and abnormal ocular motility. Nevertheless, bilateral horizontal gaze palsies are exceptionally rarely seen. We present the case of a 24-year-old female who came to our pediatric ophthalmology clinic complaining of bilateral horizontal gaze palsy, photophobia, and eye pain for 2 days. Although the patient had a family history of MS, there was no similar or previous complaint, with an unremarkable past medical and surgical history. During the examination, she was found to have a complete bilateral absence of horizontal saccade and pursuit, with slight limitations in vertical ones. There was no nystagmus or skew deviation, and the rest of the cranial nerves (CNs) were intact. Her ocular vital signs were normal, and her corrected visual acuity was 20/20 with full-color vision. The rest of the physical and neurological examinations were unremarkable. After referral to neurology, the magnetic resonance imaging showed multiple hyperintense lesions in deep white matter, pons, and midbrain. The correlation of imaging findings with clinical presentation confirmed the diagnosis of a clinically isolated syndrome. Extra-ocular motility (EOM) significantly improved after pulse steroid therapy and five sessions of plasma exchange, but the patient developed 35 prism diopter of acquired concomitant esotropia. She underwent a right medial rectus botulinum toxin injection which dramatically improved her condition, and became orthotropic during the last 2 months of follow-up after the injection.
PubMed: 38628416
DOI: 10.4103/sjopt.sjopt_106_23 -
PloS One 2024Tinnitus is a common annoying symptom without effective and accepted treatment. In this controlled experimental study, photobiomodulation therapy (PBMT), which uses...
Tinnitus is a common annoying symptom without effective and accepted treatment. In this controlled experimental study, photobiomodulation therapy (PBMT), which uses light to modulate and repair target tissue, was used to treat sodium salicylate (SS)-induced tinnitus in a rat animal model. Here, PBMT was performed simultaneously on the peripheral and central regions involved in tinnitus. The results were evaluated using objective tests including gap pre-pulse inhibition of acoustic startle (GPIAS), auditory brainstem response (ABR) and immunohistochemistry (IHC). Harmful neural plasticity induced by tinnitus was detected by doublecortin (DCX) protein expression, a known marker of neural plasticity. PBMT parameters were 808 nm wavelength, 165 mW/cm2 power density, and 99 J/cm2 energy density. In the tinnitus group, the mean gap in noise (GIN) value of GPIAS test was significantly decreased indicated the occurrence of an additional perceived sound like tinnitus and also the mean ABR threshold and brainstem transmission time (BTT) were significantly increased. In addition, a significant increase in DCX expression in the dorsal cochlear nucleus (DCN), dentate gyrus (DG) and the parafloccular lobe (PFL) of cerebellum was observed in the tinnitus group. In PBMT group, a significant increase in the GIN value, a significant decrease in the ABR threshold and BTT, and also significant reduction of DCX expression in the DG were observed. Based on our findings, PBMT has the potential to be used in the management of SS-induced tinnitus.
Topics: Rats; Animals; Sodium Salicylate; Tinnitus; Low-Level Light Therapy; Cochlear Nucleus; Neuronal Plasticity
PubMed: 38626075
DOI: 10.1371/journal.pone.0296607 -
Brain Structure & Function Jun 2024The noradrenergic nucleus Locus Coeruleus (LC) is precociously involved in Alzheimer's Disease (AD) pathology, and its degeneration progresses during the course of the...
The noradrenergic nucleus Locus Coeruleus (LC) is precociously involved in Alzheimer's Disease (AD) pathology, and its degeneration progresses during the course of the disease. Using Magnetic Resonance Imaging (MRI), researchers showed also in vivo in patients the disruption of LC, which can be observed both in Mild Cognitively Impaired individuals and AD demented patients. In this study, we report the results of a follow-up neuroradiological assessment, in which we evaluated the LC degeneration overtime in a group of cognitively impaired patients, submitted to MRI both at baseline and at the end of a 2.5-year follow-up. We found that a progressive LC disruption can be observed also in vivo, involving the entire nucleus and associated with clinical diagnosis. Our findings parallel neuropathological ones, which showed a continuous increase of neuronal death and volumetric atrophy within the LC with the progression of Braak's stages for neurofibrillary pathology. This supports the reliability of MRI as a tool for exploring the integrity of the central noradrenergic system in neurodegenerative disorders.
Topics: Humans; Locus Coeruleus; Alzheimer Disease; Disease Progression; Aged; Male; Female; Magnetic Resonance Imaging; Aged, 80 and over; Follow-Up Studies; Neuroimaging; Nerve Degeneration; Atrophy; Middle Aged; Cognitive Dysfunction
PubMed: 38625557
DOI: 10.1007/s00429-024-02797-1 -
Cureus Mar 2024Carcinomatous meningitis (CM) is characterized by the multifocal dissemination of malignant cells into the cerebrospinal fluid (CSF), pia mater, and subarachnoid space....
Carcinomatous meningitis (CM) is characterized by the multifocal dissemination of malignant cells into the cerebrospinal fluid (CSF), pia mater, and subarachnoid space. Involvement can occur in the advanced stage of malignancy, causing multifocal involvement and a wide array of symptoms. Diagnosis requires suspicions and a multimodal approach that includes imaging, lumbar puncture, and diagnostic laboratory evaluation. This case represents a female with a history of non-Hodgkin's lymphoma (NHL) and venous thromboembolism on chronic anticoagulation who presented due to acute encephalopathy, hallucinations, and right cranial nerve III palsy for 10 days before arrival. Computed tomography (CT) and angiography of the brain did not show any intracranial abnormalities. Subsequent magnetic resonance imaging (MRI) was without signs of infarction, hemorrhage, or abnormal enhancement, with the MRI of the orbits showing asymmetric linear enhancement anterior to the superior pons and midbrain on the right. Initial differential included a paraneoplastic syndrome, but there was no obvious evidence of pathological enhancement on MRI. Due to progressive bulbar symptoms, a lumbar puncture was performed with cerebrospinal fluid diagnostic workup with cytology showing monoclonal B-cell proliferation consistent with lymphoma. This case illustrates a rare but specific finding of CM as cranial nerve III palsy symptoms in this patient who did not have imaging findings that would reflect her symptoms on the initial MRI of the brain. Furthermore, diagnosing CM is complex and involves a combination of multiple diagnostic and treatment modalities. It is important to recognize the condition early to improve the patient's quality of life, prolong survival, and stabilize neurological deterioration.
PubMed: 38623120
DOI: 10.7759/cureus.56277 -
Cephalalgia : An International Journal... Apr 2024Functional anatomical research proposed the existence of a bilateral trigeminal ascending system although the anatomy trajectories of the trigeminothalamic connections...
BACKGROUND
Functional anatomical research proposed the existence of a bilateral trigeminal ascending system although the anatomy trajectories of the trigeminothalamic connections cranial to the pons remain largely elusive. This study therefore aimed to clarify the anatomical distributions of the trigeminothalamic connections in humans.
METHODS
Advanced deterministic tractography to an averaged template of diffusion tensor imaging data from 1065 subjects from the Human Connectome Project was used. Seedings masks were placed in Montreal Neurological Institute standard space by use of the BigBrain histological dataset. Waypoint masks of the sensory thalamus was obtained from the Brainnetome Atlas.
RESULTS
Tractography results were validated by use of the BigBrain histological dataset and Polarized Light Imaging microscopy. The trigeminothalamic tract bifurcated into a decussating ventral and a non-decussating dorsal tract. The ventral and dorsal tracts ascended to the contralateral thalamus and ipsilateral thalamus and reflected the ventral trigeminothalamic tract and the dorsal trigeminothalamic tract, respectively. The projection of the ventral trigeminothalamic tract and the dorsal trigeminothalamic tract to both thalami confirm the existence of a bilateral trigeminothalamic system in humans.
CONCLUSIONS
Because our study is strictly anatomical, no further conclusions can be drawn with regard to physiological functionality. Future research should explore if the dorsal trigeminothalamic tract and the ventral trigeminothalamic tract actually transmit signals from noxious stimuli, this offers potential in understanding and possibly treating neuropathology in the orofacial region.
Topics: Humans; Connectome; Diffusion Tensor Imaging; Pons; Skull; Thalamus
PubMed: 38613234
DOI: 10.1177/03331024241235168 -
BMC Anesthesiology Apr 2024Aneurysmal subarachnoid hemorrhage (aSAH) is preferentially treated by prompt endovascular coiling, which is not available in Guadeloupe. Subsequently, patients are... (Observational Study)
Observational Study
BACKGROUND
Aneurysmal subarachnoid hemorrhage (aSAH) is preferentially treated by prompt endovascular coiling, which is not available in Guadeloupe. Subsequently, patients are transferred to Paris, France mainland, by commercial airplane (6751 km flight) after being managed according to guidelines. This study describes the characteristics, management and outcomes related to these patients.
METHODS
Retrospective observational cohort study of 148 patients admitted in intensive care unit for a suspected aSAH and transferred by airplane over a 10-year period (2010-2019).
RESULTS
The median [interquartile range] age was 53 [45-64] years and 61% were female. On admission, Glasgow coma scale was 15 [13-15], World Federation of Neurological Surgeons (WFNS) grading scale was 1 [1-3] and Fisher scale was 4 [2-4]. External ventricular drainage and mechanical ventilation were performed prior to the flight respectively in 42% and 47% of patients. One-year mortality was 16% over the study period. By COX logistic regression analysis, acute hydrocephalus (hazard ratio [HR] 2.34, 95% confidence interval [CI] 0.98-5.58) prior to airplane transfer, WFNS grading scale on admission (HR 1.53, 95% CI 1.16-2.02) and age (OR 1.03, 95% 1.00-1.07) were associated with one-year mortality.
CONCLUSION
When necessary, transatlantic air transfer of patients with suspected aSAH after management according to local guidelines seems feasible and safe.
Topics: Humans; Female; Middle Aged; Male; Retrospective Studies; Subarachnoid Hemorrhage; Aircraft; Drainage; France
PubMed: 38609864
DOI: 10.1186/s12871-024-02532-7