Neuronal activity in the monkey prefrontal cortex during a duration discrimination task with visual and auditory cues.

To investigate neuronal processing involved in the integration of auditory and visual signals for time perception, we examined neuronal activity in prefrontal cortex (PFC) of macaque monkeys during a duration discrimination task with auditory and visual cues. In the task, two cues were consecutively presented for different durations between 0.2 and 1.

Locomotor kinematics and EMG activity during quadrupedal versus bipedal gait in the Japanese macaque.

Several qualitative features distinguish bipedal from quadrupedal locomotion in mammals. In this study we show quantitative differences between quadrupedal and bipedal gait in the Japanese monkey in terms of gait patterns, trunk/hindlimb kinematics, and electromyographic (EMG) activity, obtained from 3 macaques during treadmill walking. We predicted that as a consequence of an almost upright body axis, bipedal gait would show properties consistent with temporal and spatial optimization countering higher trunk/hindlimb loads and a less stable center of mass (CoM).

Neuronal representation of duration discrimination in the monkey striatum.

Functional imaging and lesion studies in humans and animals suggest that the basal ganglia are crucial for temporal information processing. To elucidate neuronal mechanisms of interval timing in the basal ganglia, we recorded single-unit activity from the striatum of two monkeys while they performed a visual duration discrimination task. In the task, blue and red cues of different durations (0.

Effects of pulsed magnetic stimulation on isolated crayfish heart.

Cardiac muscular contraction of the neurogenic heart that could be excited by pulsed magnetic stimulation (PMS) was investigated using preparation of the isolated crayfish heart. When a figure-eight magnetic coil was set over the isolated heart, cardiac contraction induced by a single PMS was not observed. Cardiac arrest occurred immediately after repetitive PMS and persisted for dozens of seconds depending on the number of stimuli.

Functional properties of parietal hand manipulation-related neurons and mirror neurons responding to vision of own hand action.

Parietofrontal pathways play an important role in visually guided motor control. In this pathway, hand manipulation-related neurons in the inferior parietal lobule represent 3-D properties of an object and motor patterns to grasp it. Furthermore, mirror neurons show visual responses that are concerned with the actions of others and motor-related activity during execution of the same grasping action.

Influence of background complexity on visual sensitivity and binocular summation using patterns with and without noise.

Purpose: To investigate how background complexity influences visual sensitivity and binocular summation.

Methods: Using two noise backgrounds (noise-sparse and noise-dense) and two corresponding noise-free backgrounds with the same luminance for each noise background, monocular and binocular thresholds were measured in six visually normal subjects (average age, 27.3 ± 1.

Influence of target size and eccentricity on binocular summation of reaction time in kinetic perimetry.

To assess how target size and eccentricity affect binocular summation (BS) of reaction time (RT) at suprathreshold level, we measured RT using targets of 0.108° and 0.216° at four eccentricities (0°, 5°, 15°, 25°) in six normal volunteers.

Shared mapping of own and others' bodies in visuotactile bimodal area of monkey parietal cortex.

Parietal cortex contributes to body representations by integrating visual and somatosensory inputs. Because mirror neurons in ventral premotor and parietal cortices represent visual images of others' actions on the intrinsic motor representation of the self, this matching system may play important roles in recognizing actions performed by others. However, where and how the brain represents others' bodies and correlates self and other body representations remain unclear.

Temporal filtering by prefrontal neurons in duration discrimination.

Neural imaging studies have revealed that the prefrontal cortex (PFC) participates in time perception. However, actual functional roles remain unclear. We trained two monkeys to perform a duration-discrimination task, in which two visual cues were presented consecutively for different durations ranging from 0.

Striatal neurons encoded temporal information in duration discrimination task.

To clarify the roles of the basal ganglia in time perception, single-unit activity was recorded from both sides of the striatum of a monkey performing a duration discrimination task. In the task, two visual cues were presented successively in different durations (0.2 approximately 1.

Delay period activity of monkey prefrontal neurones during duration-discrimination task.

Evidence from brain imaging studies has indicated involvement of the prefrontal cortex (PFC) in time perception; however, the role of this area remains unclear. To address this issue, we recorded single neuronal activity from the PFC of two monkeys while they performed a duration-discrimination task. In the task, two visual cues (a blue or red square) were presented consecutively followed by delay periods and subjects then chose the cue presented for the longer duration.

Phosphate metabolites in muscular contraction caused by magnetic stimulation.

The metabolism of high energy phosphates during muscular contraction due to direct electrical stimulation, indirect stimulation via nerve excitation, and magnetic stimulation was studied in isolated muscles (frog sartorius muscles) by (31)P nuclear magnetic resonance ((31)P-NMR). Twitch amplitudes elicited by each stimulus were measured alternatively at 3 mm displacement loading and 5 g weight. Both the creatine/inorganic phosphate (PCr/Pi) and pH changes were more marked in direct electrical stimulation than in magnetic stimulation.

Thalamocortical and intracortical connections of monkey cingulate motor areas.

Although there has been an increasing interest in motor functions of the cingulate motor areas, data concerning their input organization are still limited. To address this issue, the patterns of thalamic and cortical inputs to the rostral (CMAr), dorsal (CMAd), and ventral (CMAv) cingulate motor areas were investigated in the macaque monkey. Tracer injections were made into identified forelimb representations of these areas, and the distributions of retrogradely labeled neurons were analyzed in the thalamus and the frontal cortex.

Motor evoked potentials in rats with congenital hydrocephalus.

Motor evoked potential (MEP) by focal transcranial magnetic stimulation was used to test the functional integrity of the motor cortex in congenital hydrocephalic rats. Magnetic MEPs, using a figure-eight coil above the head, were recorded in the tibialis anterior muscle. The latency of transcranial magnetic MEP was 3.

Magnetically evoked EMGs in rats.

Magnetic stimulation of the brain and spinal cord was carried out in rats to record electromyogram (EMGs) from the gastrocnemius. A figure-eight coil was set over the middle of the dorsum, and shifted from the cervical vertebrae to the sacrum. The motor evoked potentials (MEPs) with 4.

The relationship between MI and SMA afferents and cerebellar and pallidal efferents in the macaque monkey.

The purpose of the present study was to determine the interrelationship between the thalamic afferents arising from the cerebellum (Cb) and the internal segment of the globus pallidus (GPi) with the neurons projecting to the primary motor cortex (MI) and to the supplementary motor area (SMA). We combined fluorescent retrograde tracers with a double anterograde labeling technique. Multiple injections of a combination of Diamidino Yellow and Fast Blue were made into either the MI or SMA hand/arm representation as determined by intracortical microstimulation.

Effects of morphine on two types of nucleus raphe dorsalis neurons in awake cats.

Forty-nine neurons recorded within the nucleus raphe dorsalis (NRD) in awake cats were classified into 2 groups: 29 regularly firing (clock-like) and 20 irregularly firing (non-clock-like) neurons. Hardly any of the clock-like neurons were influenced either by noxious stimulation (0.1 ml of 5% formalin, s.