scholarly journals Eye-Region Specific Ribbon Tuning Supports Distinct Modes of Synaptic Transmission in Same-Type Cone-Photoreceptors

2021 ◽  
Author(s):  
Cornelius Schröder ◽  
Jonathan Oesterle ◽  
Philipp Berens ◽  
Takeshi Yoshimatsu ◽  
Tom Baden
Keyword(s):  
Single Type ◽  
Functional Requirements ◽  
Synaptic Ultrastructure ◽  
Recent Developments ◽  
Section Electron ◽  
Dual Colour ◽  
Serial Section Electron Microscopy ◽  
Different Response ◽  
Vesicle Pool

SummaryMany sensory systems use ribbon-type synapses to transmit their signals to downstream circuits. The properties of this synaptic transfer fundamentally dictate which aspects in the original stimulus will be accentuated or suppressed, thereby partially defining the detection limits of the circuit. Accordingly, sensory neurons have evolved a wide variety of ribbon geometries and vesicle pool properties to best support their diverse functional requirements. However, the need for diverse synaptic functions does not only arise across neuron types, but also within. Here we show that UV-cones, a single type of photoreceptor of the larval zebrafish eye, exhibit striking differences in their synaptic ultrastructure and consequent calcium to glutamate transfer function depending on their location in the eye. We arrive at this conclusion by combining serial section electron microscopy and simultaneous “dual-colour” 2-photon imaging of calcium and glutamate signals from the same synapse in vivo. We further use the functional dataset to fit a cascade-like model of the ribbon synapse with different vesicle pool sizes, transfer rates and other synaptic properties. Exploiting recent developments in simulation-based inference, we obtain full posterior estimates for the parameters and compare these across different retinal regions. The model enables us to extrapolate to new stimuli and to systematically investigate different response behaviours of various ribbon configurations. We also provide an interactive, easy-to-use version of this model as an online tool. Overall, we show that already on the synaptic level of single neuron types there exist highly specialized mechanisms which are advantageous for the encoding of different visual features.

scholarly journals Distinct Synaptic Transfer Functions in Same-Type Photoreceptors

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Cornelius Schroeder ◽  
Jonathan Oesterle ◽  
Philipp Berens ◽  
Takeshi Yoshimatsu ◽  
Tom Baden
Keyword(s):  
Transfer Functions ◽  
Single Type ◽  
Functional Requirements ◽  
Synaptic Ultrastructure ◽  
Recent Developments ◽  
Section Electron ◽  
Dual Colour ◽  
Different Response ◽  
Vesicle Pool

Many sensory systems use ribbon-type synapses to transmit their signals to downstream circuits. The properties of this synaptic transfer fundamentally dictate which aspects in the original stimulus will be accentuated or suppressed, thereby partially defining the detection limits of the circuit. Accordingly, sensory neurons have evolved a wide variety of ribbon geometries and vesicle pool properties to best support their diverse functional requirements. However, the need for diverse synaptic functions does not only arise across neuron types, but also within. Here we show that UV-cones, a single type of photoreceptor of the larval zebrafish eye, exhibit striking differences in their synaptic ultrastructure and consequent calcium to glutamate transfer function depending on their location in the eye. We arrive at this conclusion by combining serial section electron microscopy and simultaneous “dual-colour” 2-photon imaging of calcium and glutamate signals from the same synapse in vivo. We further use the functional dataset to fit a cascade-like model of the ribbon synapse with different vesicle pool sizes, transfer rates and other synaptic properties. Exploiting recent developments in simulation-based inference, we obtain full posterior estimates for the parameters and compare these across different retinal regions. The model enables us to extrapolate to new stimuli and to systematically investigate different response behaviours of various ribbon configurations. We also provide an interactive, easy-to-use version of this model as an online tool. Overall, we show that already on the synaptic level of single neuron types there exist highly specialized mechanisms which are advantageous for the encoding of different visual features.

scholarly journals Central vestibular tuning arises from patterned convergence of otolith afferents

2020 ◽  
Author(s):  
Zhikai Liu ◽  
Yukiko Kimura ◽  
Shin-ichi Higashijima ◽  
David G. Hildebrand ◽  
Joshua L. Morgan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Sensory Information ◽  
Vestibular Neurons ◽  
Section Electron ◽  
Afferent Inputs ◽  
Sensory Responses ◽  
Serial Section Electron Microscopy ◽  
The Brain ◽  
Section Electron Microscopy

AbstractAs sensory information moves through the brain, higher-order areas exhibit more complex tuning than lower areas. Though models predict this complexity is due to convergent inputs from neurons with diverse response properties, in most vertebrate systems convergence has only been inferred rather than tested directly. Here we measure sensory computations in zebrafish vestibular neurons across multiple axes in vivo. We establish that whole-cell physiological recordings reveal tuning of individual vestibular afferent inputs and their postsynaptic targets. An independent approach, serial section electron microscopy, supports the inferred connectivity. We find that afferents with similar or differing preferred directions converge on central vestibular neurons, conferring more simple or complex tuning, respectively. Our data also resolve a long-standing contradiction between anatomical and physiological analyses by revealing that sensory responses are produced by sparse but powerful inputs from vestibular afferents. Together these results provide a direct, quantifiable demonstration of feedforward input convergence in vivo.

The Infection of Cells by Bullet-Shaped Viruses

1969 ◽  
Vol 27 ◽  
pp. 372-373
Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield
Keyword(s):  
Electron Microscopy ◽  
Physical Properties ◽  
Host Cell ◽  
Thin Section ◽  
Cultured Cells ◽  
Cell Infection ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

scholarly journals Persistent luminescence nanoparticles for cancer theranostics application

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Nian Liu ◽  
Xiao Chen ◽  
Xia Sun ◽  
Xiaolian Sun ◽  
Junpeng Shi
Keyword(s):  
Uv Light ◽  
Combined Therapy ◽  
Tumor Therapy ◽  
High Sensitivity ◽  
Persistent Luminescence ◽  
Therapeutic Drugs ◽  
High Penetration ◽  
Recent Developments ◽  
Cancer Theranostics

AbstractPersistent luminescence nanoparticles (PLNPs) are unique optical materials that emit afterglow luminescence after ceasing excitation. They exhibit unexpected advantages for in vivo optical imaging of tumors, such as autofluorescence-free, high sensitivity, high penetration depth, and multiple excitation sources (UV light, LED, NIR laser, X-ray, and radiopharmaceuticals). Besides, by incorporating other functional molecules, such as photosensitizers, photothermal agents, or therapeutic drugs, PLNPs are also widely used in persistent luminescence (PersL) imaging-guided tumor therapy. In this review, we first summarize the recent developments in the synthesis and surface functionalization of PLNPs, as well as their toxicity studies. We then discuss the in vivo PersL imaging and multimodal imaging from different excitation sources. Furthermore, we highlight PLNPs-based cancer theranostics applications, such as fluorescence-guided surgery, photothermal therapy, photodynamic therapy, drug/gene delivery and combined therapy. Finally, future prospects and challenges of PLNPs in the research of translational medicine are also discussed.

Normal Synaptonemal Complex and Abnormal Recombination Nodules in Two Alleles of the Drosophila Meiotic Mutant mei-W68

Genetics ◽  
2003 ◽  
Vol 163 (4) ◽  
pp. 1337-1356 ◽  
Author(s):  
Adelaide T C Carpenter
Keyword(s):  
Electron Microscopy ◽  
Synaptonemal Complex ◽  
High Frequency ◽  
Serial Section ◽  
The Other ◽  
Wild Type ◽  
Recombination Nodules ◽  
Section Electron ◽  
Serial Section Electron Microscopy ◽  
Section Electron Microscopy

Abstract The meiotic phenotypes of two mutant alleles of the mei-W68 gene, 1 and L1, were studied by genetics and by serial-section electron microscopy. Despite no or reduced exchange, both mutant alleles have normal synaptonemal complex. However, neither has any early recombination nodules; instead, both exhibit high numbers of very long (up to 2 μm) structures here named “noodles.” These are hypothesized to be formed by the unchecked extension of identical but much shorter structures ephemerally seen in wild type, which may be precursors of early recombination nodules. Although the mei-W68L1 allele is identical to the mei-W681 allele in both the absence of early recombination nodules and a high frequency of noodles (i.e., it is amorphic for the noodle phene), it is hypomorphic in its effects on exchange and late recombination nodules. The differential effects of this allele on early and late recombination nodules are consistent with the hypothesis that Drosophila females have two separate recombination pathways—one for simple gene conversion, the other for exchange.

scholarly journals Recent Developments in Inonotus obliquus (Chaga mushroom) Polysaccharides: Isolation, Structural Characteristics, Biological Activities and Application

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1441
Author(s):  
Yangpeng Lu ◽  
Yanan Jia ◽  
Zihan Xue ◽  
Nannan Li ◽  
Junyu Liu ◽  
...  
Keyword(s):  
Biological Activities ◽  
Structural Characteristics ◽  
Potential Candidate ◽  
Health Food ◽  
Inonotus Obliquus ◽  
Recent Developments ◽  
Inonotus Obliquus Polysaccharide ◽  
Future Work

Inonotus obliquus (Chaga mushroom) is a kind of medicine and health food widely used by folk in China, Russia, Korea, and some occidental countries. Among the extracts from Inonotus obliquus, Inonotus obliquus polysaccharide (IOPS) is supposed to be one of the major bioactive components in Inonotus obliquus, which possesses antitumor, antioxidant, anti-virus, hypoglycemic, and hypolipidemic activities. In this review, the current advancements on extraction, purification, structural characteristics, and biological activities of IOPS were summarized. This review can provide significant insight into the IOPS bioactivities as their in vitro and in vivo data were summarized, and some possible mechanisms were listed. Furthermore, applications of IOPS were reviewed and discussed; IOPS might be a potential candidate for the treatment of cancers and type 2 diabetes. Besides, new perspectives for the future work of IOPS were also proposed.

scholarly journals Experimental Models for Studying HPV-Positive and HPV-Negative Penile Cancer: New Tools for An Old Disease

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 460
Author(s):  
Beatriz Medeiros-Fonseca ◽  
Antonio Cubilla ◽  
Haissa Brito ◽  
Tânia Martins ◽  
Rui Medeiros ◽  
...  
Keyword(s):  
Mouse Models ◽  
Cell Lines ◽  
Penile Cancer ◽  
Hpv Infection ◽  
Experimental Models ◽  
In Vivo Models ◽  
Recent Developments ◽  
Key Aspects

Penile cancer is an uncommon malignancy that occurs most frequently in developing countries. Two pathways for penile carcinogenesis are currently recognized: one driven by human papillomavirus (HPV) infection and another HPV-independent route, associated with chronic inflammation. Progress on the clinical management of this disease has been slow, partly due to the lack of preclinical models for translational research. However, exciting recent developments are changing this landscape, with new in vitro and in vivo models becoming available. These include mouse models for HPV+ and HPV− penile cancer and multiple cell lines representing HPV− lesions. The present review addresses these new advances, summarizing available models, comparing their characteristics and potential uses and discussing areas that require further improvement. Recent breakthroughs achieved using these models are also discussed, particularly those developments pertaining to HPV-driven cancer. Two key aspects that still require improvement are the establishment of cell lines that can represent HPV+ penile carcinomas and the development of mouse models to study metastatic disease. Overall, the growing array of in vitro and in vivo models for penile cancer provides new and useful tools for researchers in the field and is expected to accelerate pre-clinical research on this disease.

scholarly journals Nanoparticles as Adjuvants and Nanodelivery Systems for mRNA-Based Vaccines

Pharmaceutics ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 45
Author(s):  
Iman M. Alfagih ◽  
Basmah Aldosari ◽  
Bushra AlQuadeib ◽  
Alanood Almurshedi ◽  
Mariyam M. Alfagih
Keyword(s):  
Messenger Rna ◽  
Immune Cell ◽  
Natural Infection ◽  
Immunological Response ◽  
Infection Process ◽  
Dual Function ◽  
Therapeutic Vaccines ◽  
Non Invasive ◽  
Recent Developments

Messenger RNA (mRNA)-based vaccines have shown promise against infectious diseases and several types of cancer in the last two decades. Their promise can be attributed to their safety profiles, high potency, and ability to be rapidly and affordably manufactured. Now, many RNA-based vaccines are being evaluated in clinical trials as prophylactic and therapeutic vaccines. However, until recently, their development has been limited by their instability and inefficient in vivo transfection. The nanodelivery system plays a dual function in RNA-based vaccination by acting as a carrier system and as an adjuvant. That is due to its similarity to microorganisms structurally and size-wise; the nanodelivery system can augment the response by the immune system via simulating the natural infection process. Nanodelivery systems allow non-invasive mucosal administration, targeted immune cell delivery, and controlled delivery, reducing the need for multiple administrations. They also allow co-encapsulating with immunostimulators to improve the overall adjuvant capacity. The aim of this review is to discuss the recent developments and applications of biodegradable nanodelivery systems that improve RNA-based vaccine delivery and enhance the immunological response against targeted diseases.

Sign in / Sign up

Export Citation Format

Share Document