Perineuronal nets on CA2 pyramidal cells and parvalbumin-expressing cells differentially regulate hippocampal dependent memory.

Perineuronal nets (PNNs) are a specialized extracellular matrix that surround certain populations of neurons, including (inhibitory) parvalbumin (PV) expressing-interneurons throughout the brain and (excitatory) CA2 pyramidal neurons in hippocampus. PNNs are thought to regulate synaptic plasticity by stabilizing synapses and as such, could regulate learning and memory. Most often, PNN functions are queried using enzymatic degradation with chondroitinase, but that approach does not differentiate PNNs on CA2 neurons from those on adjacent PV cells.

Perineuronal nets on CA2 pyramidal cells and parvalbumin-expressing cells differentially regulate hippocampal dependent memory.

Perineuronal nets (PNNs) are a specialized extracellular matrix that surround certain populations of neurons, including (inhibitory) parvalbumin (PV) expressing-interneurons throughout the brain and (excitatory) CA2 pyramidal neurons in hippocampus. PNNs are thought to regulate synaptic plasticity by stabilizing synapses and as such, could regulate learning and memory. Most often, PNN functions are queried using enzymatic degradation with chondroitinase, but that approach does not differentiate PNNs on CA2 neurons from those on adjacent PV cells.

Accuracy of polyether and vinylpolysiloxane impressions when using different types of 3D-printed impression trays - an in vitro study.

Objectives: To investigate dimensional accuracy of polyether (PE) and vinylpolysiloxane (VPS) impressions taken with manually fabricated and 3D-printed trays.

Materials And Methods: To evaluate impression accuracy, highly precise digital data of a metallic lower jaw model with prepared teeth (regions 34 and 36), an implant (region 47) and three precision balls placed occlusally along the dental arch served as reference. PE (Impregum, 3M Oral Care) and VPS (Aquasil, Dentsply Sirona) impressions (n = 10/group) were taken with trays fabricated using different materials and manufacturing techniques (FDM: filament deposition modeling, material: Arfona Tray, Arfona; printer: Pro2, Raise3D; DLP: digital light processing, material: V-Print Tray, VOCO, printer: Max, Asiga; MPR: manual processing with light-curing plates, material: LC Tray, Müller-Omicron) including an open implant impression.

A developmental increase of inhibition promotes the emergence of hippocampal ripples.

Sharp wave-ripples (SPW-Rs) are a hippocampal network phenomenon critical for memory consolidation and planning. SPW-Rs have been extensively studied in the adult brain, yet their developmental trajectory is poorly understood. While SPWs have been recorded in rodents shortly after birth, the time point and mechanisms of ripple emergence are still unclear.

Inferring causal connectivity from pairwise recordings and optogenetics.

To understand the neural mechanisms underlying brain function, neuroscientists aim to quantify causal interactions between neurons, for instance by perturbing the activity of neuron A and measuring the effect on neuron B. Recently, manipulating neuron activity using light-sensitive opsins, optogenetics, has increased the specificity of neural perturbation. However, using widefield optogenetic interventions, multiple neurons are usually perturbed, producing a confound-any of the stimulated neurons can have affected the postsynaptic neuron making it challenging to discern which neurons produced the causal effect.

Degeneracy in epilepsy: multiple routes to hyperexcitable brain circuits and their repair.

Due to its complex and multifaceted nature, developing effective treatments for epilepsy is still a major challenge. To deal with this complexity we introduce the concept of degeneracy to the field of epilepsy research: the ability of disparate elements to cause an analogous function or malfunction. Here, we review examples of epilepsy-related degeneracy at multiple levels of brain organisation, ranging from the cellular to the network and systems level.

Silencing hippocampal CA2 reduces behavioral flexibility in spatial learning.

The hippocampus is a key structure involved in learning and remembering spatial information. However, the extent to which hippocampal region CA2 is involved in these processes remains unclear. Here, we show that chronically silencing dorsal CA2 impairs reversal learning in the Morris water maze.

PymoNNto: A Flexible Modular Toolbox for Designing Brain-Inspired Neural Networks.

The Python Modular Neural Network Toolbox (PymoNNto) provides a versatile and adaptable Python-based framework to develop and investigate brain-inspired neural networks. In contrast to other commonly used simulators such as Brian2 and NEST, PymoNNto imposes only minimal restrictions for implementation and execution. The basic structure of PymoNNto consists of one network class with several neuron- and synapse-groups.

Removable partial dentures retained by hybrid CAD/CAM cobalt-chrome double crowns: 1-year results from a prospective clinical study: CAD/CAM cobalt-chrome double crowns: 1-year results.

Objectives: Computer-aided design and manufacturing (CAD/CAM) has been successfully used to replace conventional steps in the fabrication of double crowns, creating hybrid-workflows that might facilitate the wider application of these restorations in the future. However, in-vivo data are still lacking.

Methods: A prospective clinical trial was designed in which 20 patients (median age = 69 years; n women = 10) with 73 abutment teeth who needed a double-crown-retained removable partial denture (RPD) were consecutively recruited.

CA2 beyond social memory: Evidence for a fundamental role in hippocampal information processing.

Hippocampal region CA2 has received increased attention due to its importance in social recognition memory. While its specific function remains to be identified, there are indications that CA2 plays a major role in a variety of situations, widely extending beyond social memory. In this targeted review, we highlight lines of research which have begun to converge on a more fundamental role for CA2 in hippocampus-dependent memory processing.

Disposable plastic trays and their effect on polyether and vinyl polysiloxane impression accuracy-an in vitro study.

Objectives: To evaluate the dimensional accuracy of impressions taken by use of disposable stock plastic trays and to compare performance with that of metal trays.

Materials And Methods: From a metallic model incorporating three precision balls and three abutment teeth, one-step dual-phase polyether (PE) and vinyl polysiloxane (VPS) impressions were taken using either metal or disposable plastic trays (n = 10 for each of the resulting four test groups). Respective plaster cast scans were aligned with the reference dataset to evaluate global (distance and angle deviations) and local (trueness and precision) accuracy.

Selective neuromodulation and mutual inhibition within the CA3-CA2 system can prioritize sequences for replay.

To make optimal use of previous experiences, important neural activity sequences must be prioritized during hippocampal replay. Integrating insights about the interplay between CA3 and CA2, we propose a conceptual framework that allows the two regions to control which sequences are reactivated. We suggest that neuromodulatory-gated plasticity and mutual inhibition enable discrete assembly sequences in both regions to support each other while suppressing competing sequences.

Accuracy of a New Fast-Setting Polyether Impression Material.

Purpose: To evaluate the dimensional accuracy of impressions made using a new fast-setting polyether material.

Materials And Methods: A metallic reference model with two crown preparations, one inlay preparation, and three stainless steel precision balls was digitized to create a digital reference model. Sixteen one-step impressions were made for each of the four study groups, differing in impression material (regular-setting polyether [RSP] vs fast-setting polyether [FSP]) and technique (monophase vs dualphase), for a total of 64 specimens.

Wear of resin denture teeth in partial removable dental prostheses.

Purpose: To investigate occlusal wear of resin denture teeth in partial removable dental prostheses worn by partially edentulous patients.

Methods: Thirty patients with partial removable dental prostheses were included in the study. Thirty-two patients with complete dentures served as a reference group.

Treatment with a CAD-CAM-fabricated, double-crown-retained, removable partial denture: A clinical report.

This clinical report describes treatment with a double-crown-retained, removable partial denture with a 2-year follow up. Primary and secondary crowns and a removable partial denture metal-alloy framework were fabricated using computer aided design and computer aided manufacturing (CAD-CAM) and milled from cobalt-chromium (Co-Cr) alloy.

Evaluation of small-group education on the shade determination ability of preclinical dental students-A controlled clinical trial.

Objectives: To evaluate the effect of small-group education including practical training on dental students' shade determination performance compared with a control group.

Methods: Sixty-three non-colour-blind preclinical students were asked to participate and belonged to an intervention (n = 31) and a control (n = 32) group, respectively. All students received a lecture on dental shade determination.

Electroplated telescopic retainers with zirconia primary crowns: 3-year results from a randomized clinical trial.

Objective: The objective of the study was to investigate the clinical outcome for electroplated telescopic removable dental prostheses (E-RDPs) with zirconia primary crowns.

Materials And Methods: Sixty E-RDPs, with primary crowns manufactured from either cobalt-chromium alloy or zirconia, were fabricated for 56 participants. Electroplating was used to produce gold copings directly on the telescopic primary crowns.

Short-Term Prospective Clinical Evaluation of Monolithic and Partially Veneered Zirconia Single Crowns.

Objectives: The purpose of this study was to prospectively evaluate the short-term clinical performance and esthetics of monolithic and partially (i.e., facially) veneered zirconia single crowns (MZC and PZC, respectively).

Randomized trial investigating zirconia electroplated telescopic retainers: quality of life outcomes.

Objectives: The study aims to evaluate the effect of electroplated telescopic removable dental prostheses (E-RDPs) with zirconia primary crowns on oral-health-related quality of life (OHRQoL).

Materials And Methods: For E-RDPs, electroplating is used to produce precisely fitting gold copings on telescopic primary crowns. These copings are bonded intra-orally to the denture framework.

A comparison of two digital techniques for the fabrication of complete removable dental prostheses: A pilot clinical study.

Statement Of Problem: The introduction of digital techniques might improve the quality and cost-effectiveness of treatment with complete removable dental prostheses (CDs).

Purpose: The purpose of this pilot clinical trial was to study and compare the clinical feasibility, complications during fabrication, and quality of 2 types of digitally designed CDs.

Material And Methods: Five participants were recruited into this preliminary clinical trial.

Clinical assessment of enamel wear caused by monolithic zirconia crowns.

The purpose of this study was to measure enamel wear caused by antagonistic monolithic zirconia crowns and to compare this with enamel wear caused by contralateral natural antagonists. Twenty monolithic zirconia full molar crowns were placed in 20 patients. Patients with high activity of the masseter muscle at night (bruxism) were excluded.

Retention behavior of double-crown attachments with zirconia primary and secondary crowns.

Objective: To investigate whether adequate retention of zirconia conical crown (CC) attachments can be achieved, and to investigate their long-term retention.

Methods: Sixteen individual zirconia primary crowns were produced with convergence angles of 1° or 2° (eight of each). After determination of the convergence angles of the primary crowns, monolithic zirconia secondary crowns were manufactured.

Establishing CAD/CAM in Preclinical Dental Education: Evaluation of a Hands-On Module.

The aim of this study was to evaluate a hands-on computer-assisted design/computer-assisted manufacture (CAD/CAM) module in a preclinical dental course in restorative dentistry. A controlled trial was conducted by dividing a class of 56 third-year dental students in Germany into study and control groups; allocation to the two groups depended on student schedules. Prior information about CAD/CAM-based restorations was provided for all students by means of lectures, preparation exercises, and production of gypsum casts of prepared resin teeth.

Undetected residual cement on standard or individualized all-ceramic abutments with cemented zirconia single crowns - a prospective randomized pilot trial.

Objective: To assess the frequency and amount of residual cement after attachment of monolithic zirconia crowns to standard and individualized ceramic abutments.

Material And Methods: Twenty patients (mean age 58.9 years at inclusion in the study; 30% male) were randomized to receive either a standard or an individualized abutment on a bone-level implant.