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ENeuro 2021Bilateral convergence of external stimuli is a common feature of vertebrate sensory systems. This convergence of inputs from the bilateral receptive fields allows higher...
Bilateral convergence of external stimuli is a common feature of vertebrate sensory systems. This convergence of inputs from the bilateral receptive fields allows higher order sensory perception, such as depth perception in the vertebrate visual system and stimulus localization in the auditory system. The functional role of such bilateral convergence in the olfactory system is unknown. To test whether each olfactory bulb (OB) contributes a separate piece of olfactory information, and whether information from the bilateral OB is integrated, we synchronized the activation of OBs with blue light in mice expressing ChIEF in the olfactory sensory neurons (OSNs) and behaviorally assessed the relevance of dual OBs in olfactory perception. Our findings suggest that each OB contributes separate components of olfactory information, and the mice integrate the bilaterally synchronized olfactory information for olfactory identity.
Topics: Animals; Light; Mice; Olfactory Bulb; Olfactory Perception; Olfactory Receptor Neurons; Smell
PubMed: 34413085
DOI: 10.1523/ENEURO.0070-21.2021 -
Frontiers in Cellular Neuroscience 2016Somatosensory signals and operative skills learned by unilateral limbs can be retrieved bilaterally. In terms of cellular mechanism underlying this unilateral learning...
Associations of Unilateral Whisker and Olfactory Signals Induce Synapse Formation and Memory Cell Recruitment in Bilateral Barrel Cortices: Cellular Mechanism for Unilateral Training Toward Bilateral Memory.
Somatosensory signals and operative skills learned by unilateral limbs can be retrieved bilaterally. In terms of cellular mechanism underlying this unilateral learning toward bilateral memory, we hypothesized that associative memory cells in bilateral cortices and synapse innervations between them were produced. In the examination of this hypothesis, we have observed that paired unilateral whisker and odor stimulations led to odorant-induced whisker motions in bilateral sides, which were attenuated by inhibiting the activity of barrel cortices. In the mice that showed bilateral cross-modal responses, the neurons in both sides of barrel cortices became to encode this new odor signal alongside the innate whisker signal. Axon projections and synapse formations from the barrel cortex, which was co-activated with the piriform cortex, toward its contralateral barrel cortex (CBC) were upregulated. Glutamatergic synaptic transmission in bilateral barrel cortices was upregulated and GABAergic synaptic transmission was downregulated. The associative activations of the sensory cortices facilitate new axon projection, glutamatergic synapse formation and GABAergic synapse downregulation, which drive the neurons to be recruited as associative memory cells in the bilateral cortices. Our data reveal the productions of associative memory cells and synapse innervations in bilateral sensory cortices for unilateral training toward bilateral memory.
PubMed: 28018178
DOI: 10.3389/fncel.2016.00285 -
Endocrinology, Diabetes & Metabolism... Sep 2020An 8-year-old boy with cystic fibrosis came to our attention for an empty scrotum. General physical examination showed a normal penis and hypoplastic scrotum with...
SUMMARY
An 8-year-old boy with cystic fibrosis came to our attention for an empty scrotum. General physical examination showed a normal penis and hypoplastic scrotum with non-palpable testes bilaterally. Routine blood investigations showed low levels of LH, testosterone, inhibin B and antiMullerian hormone and elevated levels of FSH. Karyotype was normal. An abdominal ultrasound confirmed the absence of the testes into the scrotum, in the inguinal region and abdomen. At laparoscopy were noted bilaterally hypotrophic spermatic vessels, absence of the vas deferens and a closed inner ring. Inguinal exploration found out a small residual testis and histological examination showed fibrotic tissue. This is the first case of testicular atrophy associated to CFTR mutation described. The process that led to bilateral testicular and vas deferens atrophy remains unexplained, a possible influence of CFTR dysfunction cannot be ruled out, although it is possible that these conditions are independently associated.
LEARNING POINTS
Cystic fibrosis produces a multisystemic disease which can affect also the reproductive tract. Nearly 97-98% of male patients are infertile because of congenital bilateral absence of vas deferens. A correlation between cystic fibrosis and bilateral testicular atrophy could be possible.
PubMed: 33434179
DOI: 10.1530/EDM-20-0095 -
Frontiers in Neurology 2022Stroke patients with hemiparesis display decreased beta band (13-25 Hz) rolandic activity, correlating to impaired motor function. However, clinically, patients without...
Stroke patients with hemiparesis display decreased beta band (13-25 Hz) rolandic activity, correlating to impaired motor function. However, clinically, patients without significant weakness, with small lesions far from sensorimotor cortex, exhibit bilateral decreased motor dexterity and slowed reaction times. We investigate whether these minor stroke patients also display abnormal beta band activity. Magnetoencephalographic (MEG) data were collected from nine minor stroke patients (NIHSS < 4) without significant hemiparesis, at ~1 and ~6 months postinfarct, and eight age-similar controls. Rolandic relative beta power during matching tasks and resting state, and Beta Event Related (De)Synchronization (ERD/ERS) during button press responses were analyzed. Regardless of lesion location, patients had significantly reduced relative beta power and ERS compared to controls. Abnormalities persisted over visits, and were present in both ipsi- and contra-lesional hemispheres, consistent with bilateral impairments in motor dexterity and speed. Minor stroke patients without severe weakness display reduced rolandic beta band activity in both hemispheres, which may be linked to bilaterally impaired dexterity and processing speed, implicating global connectivity dysfunction affecting sensorimotor cortex independent of lesion location. Findings not only illustrate global network disruption after minor stroke, but suggest rolandic beta band activity may be a potential biomarker and treatment target, even for minor stroke patients with small lesions far from sensorimotor areas.
PubMed: 35418932
DOI: 10.3389/fneur.2022.819603 -
Acta Ophthalmologica Scandinavica Oct 2001To study the prevalence and causes of bilateral and unilateral blindness in an elderly urban Danish population. (Clinical Trial)
Clinical Trial Randomized Controlled Trial
PURPOSE
To study the prevalence and causes of bilateral and unilateral blindness in an elderly urban Danish population.
METHODS
Data originated from a Danish epidemiologic cross-sectional random sample population eye survey conducted during the years 1986-1988. The population consisted of 1,000 inhabitants aged 60 to 80 years in Copenhagen. The participants underwent an extensive ophthalmologic examination. A participation rate of 96.9% was achieved. Any blindness was defined as best-corrected visual acuity (VA) worse than 0.05 (the WHO criteria) and VA of 0.1 or worse (the National criteria (NC) of blindness).
RESULTS
The prevalence rates of bilateral and unilateral blindness were, respectively, 0.53% and 3.38% according to WHO, but 1.06% and 4.44% using NC. Bilateral blindness rose significantly with age (p=0.02). According to NC, age-related macular degeneration (AMD) was the leading cause of bilateral blindness, accounting for 60% of all blind persons. Glaucoma, myopic macular degeneration, cataract and retinitis pigmentosa were jointly the second most common cause, each accounting for 10% of all bilaterally blind persons. Diabetic retinopathy was not a cause of bilateral blindness. Amblyopia was the most frequent, AMD the second most frequent, and diabetic retinopathy was among the third most common cause of unilateral blindness accounting for, respectively, 28.60%, 16.66% and 9.52% of all unilateral blindness.
CONCLUSIONS
Blindness was associated with increasing age. A calculation indicates that among Danes aged 60 to 80 years 7,736 are bilaterally blind and 35,503 suffer from unilateral blindness. This study highlights AMD as the most important cause.
Topics: Aged; Aged, 80 and over; Aging; Blindness; Causality; Cross-Sectional Studies; Denmark; Eye Diseases; Female; Humans; Male; Middle Aged; Prevalence; Risk Factors; Urban Population; Visual Acuity
PubMed: 11594976
DOI: 10.1034/j.1600-0420.2001.790503.x -
Cureus May 2022Simultaneous bilateral spontaneous pneumothorax is a rare life-threatening condition that can cause severe respiratory distress, hypoxemia, and death. Spontaneous...
Simultaneous bilateral spontaneous pneumothorax is a rare life-threatening condition that can cause severe respiratory distress, hypoxemia, and death. Spontaneous pneumothorax has been reported as an uncommon but severe complication in patients recovering from COVID-19 pneumonia. Even fewer cases of spontaneous bilateral tension pneumothorax have been reported as a result of infection. We present a patient with spontaneous bilateral tension pneumothorax 18 days after COVID-19 infection. The patient's symptoms began with a substernal tearing sensation and pain radiating to the back with dyspnea. Physical exam was significant for oxygen saturation of 75% on room air, tachycardia, and diminished breath sounds bilaterally. Imaging confirmed large bilateral pneumothoraces, and chest tubes were inserted emergently to restore lung volume. Pneumothorax is predominantly observed in those with severe infection but has been seen with mild symptoms as well. The development of pneumothorax is thought to result from diffuse lung injury that occurred from a cytokine storm during COVID infection. We speculate that our patient developed bulla as a result of infection, and the bulla spontaneously ruptured, inducing the bilateral collapse of the lungs. The mortality of such an event remains unknown, but without proper intervention, mortality increases significantly in these patients. As we continue to learn about the multitude of sequelae that can result from COVID-19 infection, pneumothorax should be considered in patients with a history of COVID pneumonia that presents with acute onset of dyspnea and chest pain. It is important to quickly recognize such cases as these patients have a narrow time frame for intervention, especially in the event of bilateral tension pneumothorax. Therefore, pneumothorax should be adequately assessed on initial examination, with the possibility of bilateral pneumothoraces in mind, to minimize morbidity and mortality.
PubMed: 35733472
DOI: 10.7759/cureus.25107 -
Cureus Mar 2021We present a rare prenatal diagnosis of bilateral choroid plexus papillomas by obstetrical ultrasound and fetal MRI at 20 weeks 6 days gestation. The fetus demonstrated...
We present a rare prenatal diagnosis of bilateral choroid plexus papillomas by obstetrical ultrasound and fetal MRI at 20 weeks 6 days gestation. The fetus demonstrated bilateral enlarged, echogenic choroid plexus with increased Doppler flow suggestive of vascularized choroid tissue. Same-day fetal MRI demonstrated that the choroid plexus appeared enlarged bilaterally without definite hemorrhage. The combined features on ultrasound and MRI suggested bilateral choroid plexus papillomas with increased cerebrospinal fluid production, leading to ventriculomegaly and enlarged extra-axial spaces. The diagnosis was confirmed by postnatal pathology, which demonstrated WHO grade II atypical choroid plexus papillomas.
PubMed: 33842115
DOI: 10.7759/cureus.13737 -
Ear and Hearing 2013This study investigated whether a spectral mismatch across ears influences the benefit of redundancy, squelch, and head shadow differently in speech perception using... (Comparative Study)
Comparative Study
OBJECTIVES
This study investigated whether a spectral mismatch across ears influences the benefit of redundancy, squelch, and head shadow differently in speech perception using acoustic simulation of bilateral cochlear implant (CI) processing.
DESIGN
Ten normal-hearing subjects participated in the study, and acoustic simulations of CIs were used to test these subjects. Sentence recognition, presented unilaterally and bilaterally, was measured at +5 dB and +10 dB signal-to-noise ratios (SNRs) with bilaterally matched and mismatched conditions. Unilateral and bilateral CIs were simulated using 8-channel sine wave vocoders. Binaural spectral mismatch was introduced by changing the relative simulated insertion depths across ears. Subjects were tested while listening with headphones; head-related transfer functions were applied before the vocoder processing to preserve natural interaural level and time differences.
RESULTS
For both SNRs, greater and more consistent binaural benefit of squelch and redundancy occurred for the matched condition whereas binaural interference of squelch and redundancy occurred for the mismatched condition. However, significant binaural benefit of head shadow existed irrespective of spectral mismatches and SNRs.
CONCLUSIONS
The results suggest that bilateral spectral mismatch may have a negative impact on the binaural benefit of squelch and redundancy for bilateral CI users. The results also suggest that clinical mapping should be carefully administrated for bilateral CI users to minimize the difference in spectral patterns between the two CIs.
Topics: Acoustic Stimulation; Adult; Analysis of Variance; Cochlear Implants; Female; Humans; Male; Middle Aged; Signal-To-Noise Ratio; Speech Perception
PubMed: 22968427
DOI: 10.1097/AUD.0b013e31826709e8 -
Saudi Journal of Ophthalmology :... 2020We report a case of bilateral myelinated nerve fiber layer (MNFL) in a 24-year-old male with high hyperopia and amblyopia. He presented with poor vision bilaterally...
We report a case of bilateral myelinated nerve fiber layer (MNFL) in a 24-year-old male with high hyperopia and amblyopia. He presented with poor vision bilaterally since childhood and was evaluated for ophthalmic and systemic diseases. Retinal examination indicated MNFLs in both eyes. The presence of bilateral MNFL associated with axial hypermetropia is rare. Ametropia seems to have a stronger influence on the relative visual acuity than the presence of retinal nerve fiber myelination. Early detection of ametropia and correction with glasses might prevent further deterioration of vision.
PubMed: 34085017
DOI: 10.4103/1319-4534.310413 -
Clinical Practice and Cases in... May 2023Infectious extensor tenosynovitis is a rare infection spreading along the extensor tendons of the extremities. It presents a diagnostic challenge in the emergency...
INTRODUCTION
Infectious extensor tenosynovitis is a rare infection spreading along the extensor tendons of the extremities. It presents a diagnostic challenge in the emergency department (ED) given the nonspecific signs and symptoms, as opposed to the more common flexor tenosynovitis that is diagnosed by the classic Kanavel signs on physical exam.
CASE REPORT
Here we present a case of bilateral extensor tenosynovitis in a 52-year-old female denying past medical history who presented to the ED with two days of bilateral dorsal hand swelling and pain. She denied any risk factors such as direct trauma to the hands or intravenous drug use. The rare diagnosis was suspected in the ED due to a very high complement reactive protein level and a concerning point-of-care ultrasound. Extensor tenosynovitis was ultimately confirmed on computed tomography and by operative irrigation and drainage of the tendon sheaths.
CONCLUSION
This case demonstrates the importance of keeping extensor tenosynovitis on the differential when seeing a patient with dorsal extremity edema and pain, even if the findings occur bilaterally.
PubMed: 37285503
DOI: 10.5811/cpcem.1317