Regulating personal emotion becomes a higher priority with age and older adults report having better control over their emotions than younger adults. In this study, we used functional MRI to investigate whether the increased importance of emotion regulation with age is associated with changes in processing of emotional material. Functional magnetic resonance imaging (fMRI) was performed on a GE 3T Signa scanner. Functional whole-brain images were acquired using a gradient echo T2*-weighted spiral scan (TR=1 s; TE=30ms; flip angle=60; FOV=24 cm). Sixteen younger (20-30 years old) and 16 older (74-90 years old) adults were shown positive, negative, and neutral photographs. A recognition test was given immediately after scanning and a free recall test was administered two days later. In comparison to younger adults, older adults remembered disproportionately fewer negative photographs than positive or neutral photographs in both the recognition and free recall tests. Younger adults exhibited more activation i...

The fornix, the white matter pathway in the primate brain that connects the extended hippocampal system to the limbic thalamus, mammillary bodies, and frontal cortex, has a critical role in episodic memory, as revealed by monkey lesion (Gaffan, 1994; Bu...

In MRI studies, researchers often clean the data via pre-processing algorithms prior to analyzing registration-based volumes. The various steps in pre-processing algorithms may differentially affect the volumetric output as each pre-processing step adju...

Autism Spectrum Disorder (ASD), defined by deficits in social functioning, communication, and restricted interests/repetitive behaviors is a serious psychiatric disorder of childhood. Previous neuroimaging studies using task-based functional magnetic re...

This study investigated the brain activity associated with the unilateral wrist extension movement using EEG- equivalent current dipole localization. EEGs were recorded from 19ch on the scalp according to the international 10-20 system. EEGs were averaged during the period from 1.5 sec before to 0.5 sec after each agonist EMG onset. Movement-related cortical potential (MRCP) was analyzed by the equivalent current dipole localization, and then, the localization of dipole sources were projected onto the brain image of each subject using Magnetic Resonance Imaging (MRI). In all subjects, current dipole sources were especially localized on the contralateral primary motor cortex to the limb movement. On the other hand, that were also localized on supplementary motor cortex (SMA), pre-motor cortex, parietal association area and so on. In these localization displacements on time series, some patterns were recognized. As a whole, the localization of SMA, the pre-motor cortex and the parietal association area were ...

Introduction: By using two experimental rat models, resulting in neuronal injury in the brain, we can mimic the early and late phase of stroke. We want to characterize the death pathways and the two different types of cell death, apoptosis and necrosis, in the damaged brain tissue. We evaluate the lesions by the nerve cells morphologically, using electron microscopic (EM) techniques in combination with behavioural tests and magnetic resonance imaging (MRI). Methods: Male Spraque-Dawley rats are used. The model of compression lesion results in a penumbra zone where mainly apoptosis is seen, while the late phase stroke model results in pan-necrotic tissue. At the end of the experiment the rats are transcardially perfused, using 3% glutaraldehyde and then prepared for EM examination. After fixation the tissue is dehydrated and embedded in Agar 100, a resin of epoxy type. Ultra thin sections, mounted on formvar coated copper grids, are stained with uranyl acetate and lead citrate, The sections are examined in ...

We investigated whether gaze direction modified the pattern of finger movement activation in human cerebral cortex using functional magnetic resonance imaging (MRI). Participants performed a sequential finger-tapping task or made no finger movements while maintaining gaze in the direction of the moving hand (aligned conditions) or away from the location of the moving hand. Functional MR signals, measured in the hemisphere contralateral to the moving hand, revealed finger movement-related activation in primary motor cortex, lateral and medial premotor cortex, and a wide extent of the lateral superior and inferior parietal lobules. In each area, the extent of the finger movement activation increased when static gaze was more aligned with the moving hand compared to when gaze was directed away from the moving hand. These data suggest the existence of large-scale cortical networks related to finger actions and indicate that skeletomotor processing in the cerebral cortex is consistently modified by gaze directi...

Brain activity associated with voluntary muscle relaxation was examined by applying event-related functional magnetic resonance imaging (fMRI) technique, which enables us to observe change of fMRI signals associated with a single motor trial. The subject voluntarily relaxed or contracted the right upper limb muscles. Each motor mode had two conditions; one required joint movement, and the other did not. Five axial images covering the primary motor area (M1) and supplementary motor area (SMA) were obtained once every second, using an echoplanar 1.5 tesla MRI scanner. One session consisted of 60 dynamic scans (i.e., 60 sec). The subject performed a single motor trial (i.e., relaxation or contraction) during one session in his own time. Ten sessions were done for each task. During fMRI scanning, electromyogram (EMG) was monitored from the right forearm muscles to identify the motor onset. We calculated the correlation between the obtained fMRI signal and the expected hemodynamic response. The muscle relaxatio...

Dysmyelinating diseases are characterized by abnormal myelin formation and function; Shiverer mice are a common model used to demonstrate this devastating condition. Microstructural abnormalities in myelin such as this have been demonstrated to produce ...

The use of testing during encoding is highly beneficial for long-term memory retention relative to classical repeated study strategies. This facilitation is known as the testing effect, and has been extensively demonstrated in behavioral research. Howev...