Simultaneous representation of multiple time horizons by entorhinal grid cells and CA1 place cells.

Grid cells and place cells represent the spatiotemporal continuum of an animal's past, present, and future locations. However, their spatiotemporal relationship is unclear. Here, we co-record grid and place cells in freely foraging rats.

Author Correction: The honeycomb maze provides a novel test to study hippocampal-dependent spatial navigation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Local transformations of the hippocampal cognitive map.

Grid cells are neurons active in multiple fields arranged in a hexagonal lattice and are thought to represent the "universal metric for space." However, they become nonhomogeneously distorted in polarized enclosures, which challenges this view. We found that local changes to the configuration of the enclosure induce individual grid fields to shift in a manner inversely related to their distance from the reconfigured boundary.

The honeycomb maze provides a novel test to study hippocampal-dependent spatial navigation.

Here we describe the honeycomb maze, a behavioural paradigm for the study of spatial navigation in rats. The maze consists of 37 platforms that can be raised or lowered independently. Place navigation requires an animal to go to a goal platform from any of several start platforms via a series of sequential choices.

Framing the grid: effect of boundaries on grid cells and navigation.

Cells in the mammalian hippocampal formation subserve neuronal representations of environmental location and support navigation in familiar environments. Grid cells constitute one of the main cell types in the hippocampal formation and are widely believed to represent a universal metric of space independent of external stimuli. Recent evidence showing that grid symmetry is distorted in non-symmetrical environments suggests that a re-examination of this hypothesis is warranted.

Grid cell symmetry is shaped by environmental geometry.

Grid cells represent an animal's location by firing in multiple fields arranged in a striking hexagonal array. Such an impressive and constant regularity prompted suggestions that grid cells represent a universal and environmental-invariant metric for navigation. Originally the properties of grid patterns were believed to be independent of the shape of the environment and this notion has dominated almost all theoretical grid cell models.

Nine year follow-up of a ceramic-on-ceramic bearing total hip arthroplasty utilizing a layered monoblock acetabular component.

Introduction: Early ceramic bearing systems in total hip arthoplasty (THA) sought to provide long term wear improvement over traditional metal on polyethylene systems. However, previous designs exhibited fractures of the ceramic acetabular liner, leading to the development of the Implex Hedrocel ceramic bearing THA system where the ceramic liner was supported on a layer of polyethylene intended to transition liner loads to the metal shell, a so-called "sandwich" design. Unfortunately, the device trial was stopped to further enrollment when liner fractures were reported.

Health care provider management of patients with type 2 diabetes mellitus: analysis of trends in attitudes and practices.

Objective: To identify attitudes and practices of endocrinologists (ENDOs), family practitioners (FPs), internists (IMs), primary care nurse practitioners (NPs), physician assistants (PAs), certified diabetes educators (CDEs), retail pharmacists (R-PHs), and hospital pharmacists (H-PHs) with respect to type 2 diabetes mellitus (T2DM) management; to compare current study data with results from a similar 2011 study.

Methods: A nominal group technique focus group identified barriers to optimal management of patients with T2DM. Five case-vignette surveys were created, 1 for each group of health care professionals (HCPs): ENDOs; FPs and IMs; NPs and PAs; CDEs; and R-PHs and H-PHs.

The consequences of diminishing industry support on the independent education landscape: an evidence-based analysis of the perceived and realistic impact on professional development and patient care among oncologists.

In recent years, commercial funding for continuing medical education (CME) has dropped significantly. Yet, little has been written about how this might affect CME in oncology, a field in which new drugs and advances emerge at a rapid pace. This study examines the role oncologists and oncology fellows say that CME plays in their ongoing professional development and their attitudes about the potential and realistic impact upon both the dissemination of medical information and the impact on patient care if commercial support were removed from CME.

How environment geometry affects grid cell symmetry and what we can learn from it.

The mammalian hippocampal formation provides neuronal representations of environmental location but the underlying mechanisms are unclear. The majority of cells in medial entorhinal cortex and parasubiculum show spatially periodic firing patterns. Grid cells exhibit hexagonal symmetry and form an important subset of this more general class.

Current pathology practices in and barriers to MDS diagnosis.

Myelodysplastic syndromes (MDS) are a heterogeneous group of hematopoietic stem cell malignancies that represent a diagnostic challenge for pathologists. Accurate classification and prognostic scoring are essential to treating MDS. To understand factors that affect MDS management, a case-based survey was distributed to hematopathologists (n=53) and general pathologists (n=72) to identify perceived barriers, attitudes, and practices in MDS diagnosis.

Risk assessment and counseling behaviors of healthcare professionals managing patients with chronic pain: a national multifaceted assessment of physicians, pharmacists, and their patients.

Introduction: Due to the significant and increasing problem of chronic pain in the United States, pain management is a frequent need in many healthcare settings. At the same time, there has been rising concern with the abuse/misuse and potential for addiction to opioid therapies. This study was conducted to better understand healthcare professionals' current knowledge, perceptions, and clinical practice patterns regarding prescribing of extended-release or long-acting opioid therapy to patients with chronic pain.

Extended-release/long-acting opioid REMS may fill the need for prescribers' appropriate use education.

The Food and Drug Administration (FDA) is requiring manufacturers of long-acting and extended-release opioids to have a class-wide Risk Evaluation and Mitigation Strategy (REMS). The comprehensive risk management plan will include training for prescribers on the appropriate and safe use of these pain medications. The letter dated April 19, 2011 from FDA to manufacturers outlining the REMS requirements describes voluntary training that should be certified education "where practicable.

A modified intramedullary nail interlocking design yields improved stability for fatigue cycling in a canine femur fracture model.

Intramedullary nailing has evolved to become the standard of care for most diaphyseal femoral and tibial fractures, as well as an expanding number of metaphyseal fractures. Owing to the unstable nature of some fractures, the intramedullary device may be subjected to significant stresses owing to a lack of solid cortical contact after nailing. In such cases, excessive interfragmentary motion (due to construct toggle) has been shown to occur.

Cerebral venous and sinus thrombosis associated with subcutaneous immunoglobulin injection and oral contraceptive use.

Although patients of cerebral sinus thrombosis after intravenous immunoglobulin (IVIG) has been previously reported; reports of cerebral venous thrombosis secondary to subcutaneous injection of immunoglobulin (SIG) in conjunction with oral contraceptives are nonexistent in the current literature. We describe here a patient of cerebral venous and sinus thrombosis occurring after the combination of SIG and oral contraceptive use. Furthermore, we shall explore proper clinical precautions for someone who receives IG therapy, especially in conjunction with the use of oral contraceptives.

Boundary vector cells in the subiculum of the hippocampal formation.

"Boundary vector cells" were predicted to exist by computational models of the environmental inputs underlying the spatial firing patterns of hippocampal place cells (O'Keefe and Burgess, 1996; Burgess et al., 2000; Hartley et al., 2000).

Environmental novelty elicits a later theta phase of firing in CA1 but not subiculum.

The mechanism supporting the role of the hippocampal formation in novelty detection remains controversial. A comparator function has been variously ascribed to CA1 or subiculum, whereas the theta rhythm has been suggested to separate neural firing into encoding and retrieval phases. We investigated theta phase of firing in principal cells in subiculum and CA1 as rats foraged in familiar and novel environments.

Rearing on hind legs, environmental novelty, and the hippocampal formation.

Many mammals spontaneously rear on their hind legs in response to novelty. The current paper is the first review of rearing behaviour, and is intended to collate findings from different perspectives that are not usually brought together. We suggest that rearing is a useful marker of environmental novelty, that the hippocampal formation is a crucial component of the system controlling rearing in novel environments, and that rearing is one of several ethological measures that can profitably be used to assess hippocampal learning and memory.

The boundary vector cell model of place cell firing and spatial memory.

We review evidence for the boundary vector cell model of the environmental determinants of the firing of hippocampal place cells. Preliminary experimental results are presented concerning the effects of addition or removal of environmental boundaries on place cell firing and evidence that boundary vector cells may exist in the subiculum. We review and update computational simulations predicting the location of human search within a virtual environment of variable geometry, assuming that boundary vector cells provide one of the input representations of location used in mammalian spatial memory.

Preserved performance in a hippocampal-dependent spatial task despite complete place cell remapping.

The spatially localized firing of hippocampal place cells is thought to underlie the navigational function of the hippocampus. Performance on a spatial task learned using a particular place cell map should therefore deteriorate if the map is disrupted. To test this prediction, we trained rats on a hippocampal-dependent spatial task in a black box and tested them in a white box.