Subjects were trained on a pursuit task in which the target trajectory was predictable only on the horizontal axis. Half of them were sleep deprived on the first post-training night ( n = 13). Three days later, functional magnetic resonance imaging revealed task-related increases in brain responses to the learned trajectory, as compared with a new trajectory. In the sleeping group ( n = 12) as compared with the sleep-deprived group, subjects' performance was improved, and their brain activity was greater in the superior temporal sulcus (STS). Increased functional connectivity was observed between the STS and the cerebellum and between the supplementary eye field and the frontal eye field. These differences indicate sleep-related plastic changes during motor skill learning in areas involved in smooth pursuit eye movements.

This study utilized functional MRI to evaluate the early stages of a kainic acid induced seizure in a fully conscious rat. Seizure activity was confirmed by EEG, and blood oxygen level dependant (BOLD) signal was temporally consistent with this activity. Male SD rats where anesthetized using medetomidine (Pfizer) and ketamine and EEG electrodes were implanted. The animal was then placed into a special animal restraint/Rf coil system (Insight Neuroimaging systems). This system was put into a 4.7T MRI (Bruker) and the animal was awoken with atipamizole (Pfizer). Physiologic parameters were recorded for the entire duration of the experiment. Anatomical images were acquired before and after the seizure. A 45 repetition functional sequence was acquired with 14 baseline repetitions (3 minutes) followed by an IP injection of kainic acid (10mg/kg). Seizure activity was noted via EEG within a minute. The anatomical images were subtracted to confirm that the awake animal remained immobile during the experiment. All ...

Functional magnetic resonance imaging (fMRI) was used in rats to study CNS effects of the dopamine D2/3 receptor agonist quinelorane in vivo. Male Sprague-Dawley rats (250-300g, n=5 per group) were anaesthetised (α-chloralose, 60mg/kg i.v. bolus, then 30mg/kg/hr) and scanned using multi-echo gradient echo imaging (TE=5,10 and 15ms, TR =460ms, 120 volumes in 2 hours). Quinelorane (30µg/kg, s.c.) or saline vehicle were randomly administered 30-60 minutes after scan initiation. Mean echo images were realigned, normalised to a rat-brain template and analysed using a general linear model[1]. Statistically significant signal intensity increases over controls (T>4.3, p<0.05) were detected within the nucleus accumbens, ventromedial striatum and olfactory nuclei. These results are consistent with previous microdialysis experiments where quinelorane, a potent D3 receptor agonist with high D3/D2 selectivity[2], reduced dopamine release in the nucleus accumbens and ventral striatum[3], areas rich in D3 receptors[2]. O...

Human hand dexterity depends on the ability to move digits independently and to combine these movements in various coordinative patterns. It is well established that the primary motor cortex (M1) is important for skillful digit actions but less is known about the role played by the nonprimary motor centers. Here we use functional magnetic resonance imaging to examine the hypothesis that nonprimary motor areas and the posterior parietal cortex are strongly activated when healthy humans move the right digits in a skillful coordination pattern involving relatively independent digit movements. A task in which flexion of the thumb is accompanied by extension of the fingers and vice versa, i.e., a learned “nonsynergistic” coordination pattern, is contrasted with a task in which all digits flex and extend simultaneously in an innate synergistic coordination pattern (opening and closing the fist). The motor output is the same in the two conditions. Thus, the difference when contrasting the nonsynergistic and syner...

Previous functional neuroimaging studies have characterized brain systems mediating associative learning using classical delay conditioning paradigms. In the present study, we used event-related functional magnetic resonance imaging to characterize neuronal responses mediating aversive trace conditioning. During conditioning, neutral auditory tones were paired with an aversive sound [unconditioned stimulus (US)]. We compared neuronal responses evoked by conditioned (CS+) and nonconditioned (CS−) stimuli in which a 50% pairing of CS+ and the US enabled us to limit our analysis to responses evoked by the CS+ alone. Differential responses (CS+ vs CS−), related to conditioning, were observed in anterior cingulate and anterior insula, regions previously implicated in delay fear conditioning. Differential responses were also observed in the amygdala and hippocampus that were best characterized with a time × stimulus interaction, indicating rapid adaptation of CS+-specific responses in medial temporal lobe. These...

The purpose of this study was to determine brain networks involved in motion perception of sounds. Ten healthy young volunteers measured their brain activity during a sound localization task and control tasks using functional MRI. An event-related design was used in this study. Stereo sounds moving in the 3D space were created by a personal computer, and presented binaurally through a pair of air conduct headphones during the sound localization task. And subjects were asked to judge the location and direction of the moving sounds. During the control task, non-moving sounds were used for stimuli. The intraparietal, premotor cortices of the bilateral hemisphere, and the cerebellar vermis were specifically activated during the sound localization task. These areas are believed to be involved in control of eye movements. Although, task-related eye movements were not observed in this study. Therefore, our results indicate that brain networks consist of these areas are related to motion perception of sounds, and ...

In order to find out whether it is possible to detect EH with a 4.7 T MRI device, five guinea pigs were used for evaluating the dynamic change of gadolinium uptake in normal cochlea n=15 and experimental induced EH. Two kinds of operation were used to obtain an EH-endolymphatic sac (ES) intact group (n=6) and ES -damaged group (n=9). D-aldosterone (1 mg/kg) was given to 6 animals in the ES -damaged group, injected 8-9 days after ES surgery. MRI was performed and hearing was tested by ECoG in the ES- damaged group. It was found that as early as 5 days after ES surgery, EH started in all animals as verified by MRI scannings and histology. Serious damage to the inner ear barrier was detected with MRI in one advanced stage animal, which received D-aldosterone injection with a 60 dB hearing loss. Three areas of the cochlea were measured and area factor with scala vestibuli or scala tympani as reference were used for quantitative evaluation of EH. For EH to be defined as being present 87.5 % (7/8) of all the are...

This study examines the cognitive and neural systems involved in attentional conflict and their development using functional magnetic resonance imaging. Attentional conflict was manipulated by presenting compatible (> > >) or incompatible (> < >) flankers on either side of a target stimulus. Subjects were instructed to press the right button if the center arrow pointed right (>) and the left button if the center arrow pointed left (<). The salience of flankers was manipulated by parametrically varying the number of compatible trials preceding an incompatible trial by 1, 3 or 5. Eight subjects (4 female) were scanned using a rapid mixed trial design during performance of the task. Adults and children were faster on compatible (518 and 678 msec) than incompatible trials (580 and 786 msec). Reaction times and activity in the anterior cingulate and dorsolateral prefrontal cortex increased for incompatible trials as a function of preceding context (1, 3, or 5 compatible trials) for the adults. Children showed l...

Language and music exhibit similar acoustic and structural properties, and both appear to be uniquely human. Several recent studies suggest that speech and music perception recruit shared computational systems, and a common substrate in Broca's area for hierarchical processing has recently been proposed. However, this claim has not been tested by directly comparing the spatial distribution of activations to speech and music processing within subjects. In the present study, participants listened to sentences, scrambled sentences, and novel melodies. As expected, large swaths of activation for both sentences and melodies were found bilaterally in the superior temporal lobe, overlapping in portions of auditory cortex. However, substantial nonoverlap was also found: sentences elicited more ventrolateral activation, whereas the melodies elicited a more dorsomedial pattern, extending into the parietal lobe. Multivariate pattern classification analyses indicate that even within the regions of blood oxygenation le...

Although it is well documented that the ability to perceive biological motion is mediated by the lateral temporal cortex, whether and when neural activity in this brain region is modulated by attention is unknown. In particular, it is unclear whether the processing of biological motion requires attention or whether such stimuli are processed preattentively. Here, we used functional magnetic resonance imaging, high-density electroencephalography, and cortically constrained source estimation methods to investigate the spatiotemporal effects of attention on the processing of biological motion. Directing attention to tool motion in overlapping movies of biological motion and tool motion suppressed the blood oxygenation level-dependent (BOLD) response of the right superior temporal sulcus (STS)/middle temporal gyrus (MTG), while directing attention to biological motion suppressed the BOLD response of the left inferior temporal sulcus (ITS)/MTG. Similarly, category-based modulation of the cortical current source...