The hippocampus is a region pivotally involved in spatial navigation and memory formation. While most of the tools available for functional magnetic resonance imaging (fMRI) analysis have been developed for human data, much of what we know about the und...

Calcium ions are ubiquitous signaling molecules in all multicellular organisms, where they mediate diverse aspects of intracellular and extracellular communication over widely varying temporal and spatial scales. Although techniques for mapping calcium-...

Background Multiple Sclerosis (MS) is a CNS disease and has been known as a white matter disease. However, recent immunohistochemical studies have demonstrated grey matter demyelination in chronic MS (Prinster et al, 2006; Bo et al, 2006). Other studies...

Embolic stroke is a significant cause of mortality and neurological deficits e.g. paralysis, throughout the world. It is a devastating complication resulting from blood clots forming elsewhere in the body and traveling through the blood stream to the br...

Fast, low-angle shoot functional magnetic resonance imaging (fMRI), based on the blood oxygenation level-dependent (BOLD) effect, was combined with optical recording of intrinsic signals (ORIS) and 2-deoxyglucose labeling in gerbil barrel cortex. We observed over the activated barrel a positive BOLD signal and increased levels of deoxyhemoglobin and total hemoglobin during each period of prolonged (30 sec) D2 vibrissal stimulation. These data show that the hemodynamic basis of this fMRI signal is not necessarily a washout of deoxyhemoglobin, as generally assumed. Instead, they suggest that a positive BOLD signal can also be caused by a local increase of blood volume, even if deoxyhemoglobin levels are persistently elevated. We also show that this alternative interpretation is consistent with theoretical models of the BOLD signal. The changes in BOLD signal and blood volume, which are most tightly correlated with the periodic stimulation, peak at the site of neuronal activation. These results contribute to ...

Our eyes are constantly in motion and the various kinds of eye movements are closely linked to many aspects of human cognitive processing. Measuring all possible eye movements unobtrusively is not achievable with current methods. Video-based eye-trackers only measure rotational but not translational motion of the eye, require a calibration process relying on the participant’s self-report of accurate fixation, and do not work if vision of the eyeball is blocked. Scleral search coils attach physical weight on the eyeball and also do not measure translation. Here we describe a novel and fully automated method to use real-time Magnetic Resonance Imaging (MRI) for eye tracking. We achieved a temporal resolution sufficient to measure eye rotations and translations as short as those that occur within a blink and behind a closed eyelid. To demonstrate this method we measured the full extent of the blink-related eye movement for two individuals, suggesting that the eye approaches a holding position during lid closu...

The functional neuroanatomy of word processing has been explored in developing readers, but the development of the purported visual word form area (VWFA) in prereaders to readers has not been explored to date using functional magnetic resonance imaging ...

Elsewhere at this meeting we present functional magnetic resonance imaging (fMRI) measurements in both monkey and human subjects performing a simple value-based decision making task. These data reveal a correspondence in the network of brain areas activ...

In this study we examine the effects of spatial and featural attention on the activity of the human lateral geniculate nucleus (LGN), superior colliculus (SC) and pulvinar using high-resolution funcitonal magnetic resonance imaging (fMRI). Two main mech...

The visual cortical response to an attended visual stimulus is larger than the response to the same stimulus when it is passively viewed. We used functional magnetic resonance imaging (fMRI) to compare blood oxygenation level-dependent (BOLD) responses ...