Torsional component of microsaccades during fixation and quick phases during optokinetic stimulation.

While many studies have characterized the eye movements during visual fixation, includ-ing microsaccades, in most cases only horizontal and vertical components have been rec-orded and analyzed. Thus, little is known about the torsional component of microsaccades. We took advantage of a newly developed software and hardware to record eye movements around the three axes of rotation during fixation and torsional optokinetic stimulus.

Evaluation of the Video Ocular Counter-Roll (vOCR) as a New Clinical Test of Otolith Function in Peripheral Vestibulopathy.

Importance: Video-oculography (VOG) goggles have been integrated into the assessment of semicircular canal function in patients with vestibular disorders. However, a similar bedside VOG method for testing otolith function is lacking.

Objective: To evaluate the use of VOG-based measurement of ocular counter-roll (vOCR) as a clinical test of otolith function.

Optogenetically transduced human ES cell-derived neural progenitors and their neuronal progenies: Phenotypic characterization and responses to optical stimulation.

Optogenetically engineered human neural progenitors (hNPs) are viewed as promising tools in regenerative neuroscience because they allow the testing of the ability of hNPs to integrate within nervous system of an appropriate host not only structurally, but also functionally based on the responses of their differentiated progenies to light. Here, we transduced H9 embryonic stem cell-derived hNPs with a lentivirus harboring human channelrhodopsin (hChR2) and differentiated them into a forebrain lineage. We extensively characterized the fate and optogenetic functionality of hChR2-hNPs in vitro with electrophysiology and immunocytochemistry.

No handedness effect on spatial orientation or ocular counter-roll during lateral head tilts.

Although vestibular inputs are bilaterally represented within the cerebral hemispheres, the higher level vestibular functions exhibit hemispheric asymmetries. Previous studies have suggested that such asymmetries are associated with handedness. Here, we studied the impact of handedness (i.

Clinical applications of control systems models: The neural integrators for eye movements.

The first models that were proposed to account for the neural control of eye movements applied a classic control systems approach, including feedback, and measured system responses to sinusoidal and transient stimuli. Although such models provided many insights, their limitations were quickly recognized, such as their inability to account for anticipatory responses. Another question was whether models with lumped transfer functions could usefully represent a population of neurons, in which individual units were shown to encode a spectrum of different signals, including resting discharge rates and noise.

Errors of Upright Perception in Patients With Vestibular Migraine.

Patients with vestibular migraine (VM) often report dizziness with changes in the head or body position. Such symptoms raise the possibility of dysfunction in neural mechanisms underlying spatial orientation in these patients. Here we addressed this issue by investigating the effect of static head tilts on errors of upright perception in a group of 27 VM patients in comparison with a group of 27 healthy controls.

Edentulism and Tooth Loss in Iran: SEPAHAN Systematic Review No. 6.

Objectives: Tooth loss appears to have an important role in the loss of mastication and esthetics. The aim of this systematic review was to investigate the prevalence of tooth loss and edentulism in the Iranian population.

Methods: Studies reviewed in this article were primarily identified via search of the online bibliographic databases including PubMed and Iranian Biomedical Journals, by using "tooth loss", "edentulism", "epidemiology", and "Iran" as keywords.

Constipation in Iran: SEPAHAN Systematic Review No. 5.

Background: Constipation is physically and mentally troublesome for many patients and has adverse effects on their quality of life. The aim of the present study was to systematically review previous studies on the epidemiology of constipation in Iran.

Methods: Bibliographic databases including PubMed, Google Scholar, and Iranian databases including Scientific Information Database, Iran Medex, and Magiran were searched to select studies that reported the prevalence of constipation in Iran.

Bloating in Iran: SEPAHAN Systematic Review No. 4.

Objectives: Bloating is a common and bothersome gastrointestinal symptom. Despite its high prevalence, associated costs, and effects on the quality of life, very few studies have reported the epidemiology of bloating in Iran. Through this systematic review, findings and limitations of the current research will be discussed.

Irritable Bowel Syndrome in Iran: SEPAHAN Systematic Review No. 1.

Objectives: Irritable bowel syndrome (IBS) is a common gastrointestinal disorder. Due to its high prevalence and absence of curative therapy, IBS has the potential to create tremendous burden on the health care system. Herein, we systematically reviewed the published literature to investigate the epidemiology of IBS in Iran.