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PubMed1999

Anatomical loops and their electrical dynamics in relation to whisking by rat.

An accumulation of anatomical, behavioral, and electrophysiological evidence allows us to identify the neuronal circuitry that is involved with vibrissa-mediated sensation and the control of rhythmic vibrissa movement. Anatomical evidence points to a multiplicity of closed sensorimotor loops, while electrophysiological data delineate the flow of electrical signals in these pathways. These loops process sensory input from the vibrissae and send projections to direct vibrissa movement, starting at the level of the hindbrain and proceeding toward loops that involve multiple structures in the forebrain. The nature of the vibrissa-related electrical signals in behaving animals has been studied extensively at the level of neocortical loops. Two types of spike signal are observed that serve as a reference of vibrissa motion: a fast signal that correlates with the relative phase of the vibrissae within a whisk cycle and a slow signal that correlates with the amplitude, and possibly the set-point, of the vibrissae during a whisk. Both signals are observed in vibrissa primary sensory (S1) cortex, and in some cases they are sufficiently robust to allow vibrissa position to be accurately estimated from the spike train of a single neuron. Unlike the case for S1 cortex, only the slow signal has been observed in vibrissa primary motor (M1) cortex. The control capabilities of M1 cortex were estimated from experiments with anesthetized animals in which progressive areas along the vibrissa motor branch were microstimulated with rhythmically applied currents. The motion of the vibrissae followed stimulation of M1 cortex only for rates that were well below the frequency of rhythmic whisking; in contrast, the vibrissae followed stimulation of the facial nucleus, whose cells directly drive the vibrissae, for rates above that of whisking. In toto, the evidence implies that there is fast signaling from the facial nucleus, through the mystacial pad and the vibrissae and up through sensory cortex, but only slow signaling at the level of the motor cortex and down through the superior colliculus to the facial nucleus. The transformation from fast sensory signals to slow motor control is an unresolved issue. On the other hand, there is a candidate scheme to understand how the fast reference of vibrissa motion in the whisk cycle may be used to decode the angle of the vibrissae upon their contact with an object. We discuss a circuit in which servo mechanisms are used to determine the angle of contact relative to the preferred phase of the fast reference signals. Support for this scheme comes from results with anesthetized animals on the frequency and phase entrainment of intrinsic neuronal oscillators in S1 cortex. A prediction based on this scheme is that the output from a decoder circuit is maximal when the angle of contact differs from the preferred phase of a fast regerence signal. In contrast, for correlation-based schemes the output is maximal when the angle of contact equals the preferred phase.

Animals↗
PubMed2003

Delayed transplantation of fibroblasts genetically modified to secrete BDNF and NT-3 into a spinal cord injury site is associated with limited recovery of function.

Delivery of neurotrophic factors in acute models of spinal cord injury in adult rats can rescue axotomized neurons, promote axonal growth, and partially restore function. The extent to which repair and recovery of function can be achieved after chronic injury has received less attention. In the companion paper we show that transplanting fibroblasts genetically modified to produce neurotrophic factors into chronic (6-week) hemisection injuries results in sprouting, partial neuroprotection, but only limited regeneration. Here we describe functional consequences of this treatment using a series of behavioral tests. Adult rats received a complete unilateral C3/C4 hemisection and recovery from the injury was assessed over 5 weeks. At 6 weeks postoperative, the experimental group received grafts of a combination of fibroblasts modified to secrete BDNF or NT-3. The operated control groups received grafts of either gelfoam or gelfoam with fibroblasts expressing GFP into the lesion site. Behavioral recovery in the three groups was assessed over the next 10 weeks. Severe deficits with no recovery in any of the groups were observed in several tests (BBB, limb preference, narrow beam, horizontal rope test) that measure primarily motor function. Recovery was observed in the grid test, a measure of sensorimotor function, and the von Frey test, a measure of response to mechanical stimulation, but there were no differences between the operated control or experimental groups. Both groups also showed recovery from heat-induced hyperalgesia, with the experimental group exhibiting greater recovery than the operated control groups. In this test, delivery of neurotrophic factors from transplanted fibroblasts does not worsen responses to nociceptive stimuli and in fact appears to reduce hypersensitivity. Our data also demonstrate that additional damage to the spinal cord upon placement of a graft further compromises behavioral recovery for locomotor and postural function. Additional therapeutic interventions will be necessary to provide greater levels of recovery after chronic injuries.

Animals↗
PubMed1999

Motor skills training enhances lesion-induced structural plasticity in the motor cortex of adult rats.

To assess behavioral experience effects on synaptic plasticity after brain damage, the present study examined the effects of complex motor skills training (the acrobatic task) on synaptic changes in layer V of the motor cortex opposite unilateral damage to the forelimb sensorimotor cortex (FLsmc). Adult male rats were given lesions or sham operations followed by 28 d of training on the acrobatic task [acrobat condition (AC)]. As a motor activity control [motor control (MC)], lesion and sham animals were given simple repetitive exercise. Previously, FLsmc lesions and acrobatic training have independently been found to result in increases in synapse to neuron ratios in the intact motor cortex relative to controls, and both of these effects were replicated in the present study. In addition, acrobat training after lesions significantly increased layer V synapses per neuron relative to sham-AC and lesion-MC rats. Thus, the combination of acrobatic training and lesions resulted in an enhanced synaptogenic response. Synapse subtypes were also differentially affected by the conditions. Lesion-MC and sham-AC primarily had increases in the number of synapses per neuron formed by multiple synaptic boutons in comparison to sham-MC. In contrast, lesion-AC had increases in both multiple and single synapses. Multiple synaptic spines and perforated synapses were also differentially affected by training versus lesions. On tests of coordinated forelimb use, lesion-AC rats performed better than lesion-MC rats. In addition to supporting a link between behavioral experience and structural plasticity after brain damage, these findings suggest that adaptive neural plasticity may be enhanced using behavioral manipulations as "therapy."

Animals↗
PubMedDate not supplied

Effects of sex and laterality on the rotatory swimming behavior of normal mice.

Clockwise and counterclockwise full turns are commonly used to assess lateralization in circling behavior. Although previous studies have reported that the rotatory swimming (ROSW) test is simple and reliable, little is known about lateralization of turns lower than 360 degrees and the amount of turning close to the wall, and even less is known about alternation of direction during a session. Here we investigated the effects of consistency of laterality and sex on 30 degree turns in center and in periphery of the swimming apparatus, and on alternation of direction upon three sessions. Approximately 80% of the turns occurred when mice swam along the wall. In side-consistent turners, this suggests the existence of an intrinsic sensorimotor asymmetry that determines the adhesion to the preferred side. Regarding categorization of side preferences, there was a high percentage of agreement between center and periphery, as well as between full turns and extra 30 degree turns (30 degree turns that do not contribute to full turns). Therefore, behavioral asymmetry in the ROSW can be assessed using 30 degree turns. There was no significant directional bias in the population, and side preference was found to be independent of sex. By contrast, after the second minute of each session, males exhibited a significantly higher number of reversal of direction (RD) as well as a higher number of RD per turn than females. The amount of RD presented by each animal is not predicted by the animal's side preference. Thus, RD is independent of preferred side of turning and depends on sex.

Animals↗
PubMed2002

Sensorimotor gating effects produced by repeated dopamine agonists in a paradigm favoring environmental conditioning.

RATIONALE: It is not known whether dopamine agonist-induced disruption of prepulse inhibition (PPI) can be conditioned to the environment, a phenomenon established for dopamine agonist-induced locomotor activation and other behaviors. Furthermore, the literature is contradictory regarding whether PPI disruption, like locomotor activity, can become sensitized after repeated dopamine agonist administration. Differences in methodology (e.g. drug-environment pairing) may have contributed to these contradictory findings. OBJECTIVES: In a series of studies, we investigated whether dopamine agonist-induced disruption of PPI could be conditioned and whether repeated administration of dopamine agonists, in a paradigm favorable to conditioning, would produce sensitization to dopamine agonist-induced disruption of PPI. METHODS: One group of rats were administered subcutaneous apomorphine (0.5 mg/kg) daily for 7 (experiment 1) or 5 (experiment 3) consecutive days contingent with startle testing (in testing rooms, immediately before test sessions). A second group received the same apomorphine dose daily in a manner non-contingent with behavioral testing (in home cages after test sessions). The following day, all rats received vehicle injections contingent with the test environment to assess for environmental conditioning (vehicle challenge day). The next day, all animals received a challenge of apomorphine (0.5 mg/kg) contingent with the test environment to assess the contribution of drug-environment pairing on changes observed in apomorphine-induced disruption of PPI (apmorphine challenge day). PPI was measured immediately after drug injections in the test environment. A separate study (experiment 2) tested amphetamine (3.0 mg/kg) using a similar methodology. In a fourth study, rats were pretreated with haloperidol (1.0 mg/kg) or saline prior to receiving daily apomorphine to see if haloperidol could modify the changes in PPI produced by repeated apomorphine administration. RESULTS: On the vehicle challenge day, PPI exhibited by the rats that received daily apomorphine contingent with the testing environment did not differ from the group that received vehicle contingent with the testing environment. However, animals receiving apomorphine contingent with testing exhibited partial tolerance to its PPI effects during the conditioning period. The PPI exhibited by both groups did not differ significantly on the apomorphine-challenge day. Amphetamine produced a complete tolerance to its PPI effects by day 3. Haloperidol pretreatment blocked the PPI tolerance produced by repeated apomorphine injections. CONCLUSIONS: These results suggest: 1) unlike locomotion, PPI disruption induced by apomorphine cannot be conditioned to the environment; 2) unlike locomotion, repeated adminstration of dopamine agonists produce tolerance, rather than sensitization, to PPI; 3) environmental factors do not seem to be critical for PPI tolerance; and 4) dopamine receptors mediate PPI tolerance to apomorphine.

Acoustic Stimulation↗
PubMed2003

Effects of ventrolateral-ventromedial thalamic lesions on motor coordination and spatial orientation in rats.

The ventrolateral-ventromedial (VL-VM) nuclei are classified as a motor area of the thalamus on the basis of predominant input from the cerebellum and the basal ganglia and output to the motor cortex. The sensitivity to electrolytic lesions of the VL-VM thalamic nuclei in rats was evaluated for tests requiring balance and equilibrium. VL-VM lesions impaired acquisition of the rotorod test but had no effect on stationary beam and hole-board tests. A selective impairment was also observed in the Morris water maze, as VL-VM thalamic lesions slowed down acquisition of the hidden platform but not the visible platform condition. These results support the hypothesis that thalamic motor nuclei participate in the acquisition of sensorimotor and spatial learning.

Animals↗
PubMed2002

CHF2819: pharmacological profile of a novel acetylcholinesterase inhibitor.

CHF2819 is a novel orally active acetylcholinesterase inhibitor (AChEI) developed for the treatment of Alzheimer's disease (AD). CHF2819 is a selective inhibitor of AChE, it is 115 times more potent against this enzyme than against butyrylcholinesterase (BuChE). Moreover, CHF2819 is more selective for inhibition of central (brain) AChE than peripheral (heart) AChE. In vivo CHF2819, 0.5, 1.5, and 4.5 mg/kg p.o., significantly and in dose-dependent manner increased acetylcholine (ACh) levels in hippocampus of young adult rats. Moreover, aging animals, with lower basal ACh levels than young adult rats, also exhibit a marked increase in hippocampal levels of this neurotransmitter after administration of CHF2819. At 1.5 mg/kg p.o. CHF2819 attenuated scopolamine-induced amnesia in a passive avoidance task. Furthermore, it decreased dopamine (DA) levels and increased extracellular levels of 5-hydroxytryptamine (5-HT) in the hippocampus, without modifying norepinephrine (NE) levels. By oral administration to young adult rats CHF2819 did not affect extracellular hippocampal levels of glutamate (Glu), aspartate (Asp), gamma-aminobutyric acid (GABA), taurine (Tau), arginine (Arg) or citrulline (Cit). Functional observational battery (FOB) screening demonstrated that CHF2819 (1.5 and 4.5 mg/kg p.o.) does not affect activity, excitability, autonomic, neuromuscular, and sensorimotor domains, as well as physiological endpoints (body weight and temperature). CHF2819 induced, however, involuntary motor movements (ranging from mild tremors to myoclonic jerks) in a dose-dependent manner. The neurochemical and behavioral profiles of CHF2819 suggest that this orally active novel AChEI could be of clinical interest for the treatment of Alzheimer-type dementia associated with multiple neurotransmitter abnormalities in the brain. In particular, CHF2819 might be a useful therapeutic drug for AD patients with cognitive impairment accompanied by depression.

Acetylcholine↗
PubMed1994

Effect of the nigrostriatal dopamine system on acquired neural responses in the striatum of behaving monkeys.

Dysfunction of the nigrostriatal dopamine system results in marked disorders of movement such as occur in Parkinson's disease. Functions of this dopamine-containing projection system were examined in monkeys trained in a classical conditioning task, and the effects of striatal dopamine depletion were tested. Unilateral dopamine loss substantially reduced the acquired sensory responsiveness of striatal neurons monitored electrophysiologically. This effect was ipsilateral and selective, and could be reversed by apomorphine. These results suggest that the primate nigrostriatal system modulates expression of neuronal response plasticity in the striatum during sensorimotor learning.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed2000

Task-dependent modulation of the sensorimotor transformation for smooth pursuit eye movements.

To investigate the transformation of retinal image velocity into smooth pursuit eye velocity, eye movements were measured in the presence of two moving targets. In the first experiment, the targets were identical in all respects except for direction of motion, and the monkey was not cued to attend to either target. In this experiment, smooth pursuit eye velocity elicited by two targets was the vector average of the response evoked by each target alone. In subsequent experiments, we examined the effects of stimulus and task parameters on the selectivity of pursuit. When the targets were made different colors and monkeys were cued for the color of the rewarded target, their pursuit eye movements were biased in the direction of the rewarded target, but still showed a substantial influence of the nonrewarded target (distractor). It did not matter whether the same target color was used for an entire session or whether the color was randomized from trial to trial. Reducing uncertainty about the axis of motion of the rewarded target also had little effect. However, the pattern of image motion appeared to have a substantial effect; radial image motion favored averaging, and winner-take-all pursuit was found only with nonradial image motion. We conclude that the sensorimotor interface for pursuit uses a flexible decision rule that can vary continuously from vector averaging to winner-take-all. We present a simple recurrent network model that reflects this range of behavior. The model has allowed us to identify three computational elements (selection bias, competitive inhibition, and response normalization) that should be taken into consideration in future models of smooth pursuit.

Analysis of Variance↗
PubMed1995

The effects of D-cycloserine and MK-801 on the performance of rats in two spatial learning and memory tasks.

The present study was undertaken to investigate the effects of modulation of the N-methyl-D-aspartate (NMDA) receptor on learning and memory. Thus, the performance of rats treated with D-cycloserine, a partial agonist at the glycine recognition site of the NMDA receptor complex, and MK-801, a noncompetitive NMDA receptor antagonist, either alone or concurrently were assessed in radial arm maze and water maze tasks. Administration of MK-801 (0.1 mg/kg, i.p.) impaired acquisition in the water maze (increased escape latency and distance) and working memory in the radial arm maze (increased re-entries) in rats. Moreover, in the radial arm maze, MK-801 disrupted locomotion (increased latencies and decreased arm entries per minute) and impaired the acquisition of reference memory (increased number of errors) performance of rats. D-Cycloserine (0.03, 0.3, 1.0, 3.0, 10 mg/kg, i.p.) had no effects on acquisition or memory performance of control or MK-801-treated rats in either of these tasks. However, D-cycloserine (0.03, 0.3, 3.0 mg/kg) reversed the MK-801-induced disruption in locomotion. Furthermore, 3.0 mg/kg D-cycloserine increased behavioral activity and also decreased the time needed to complete the task in control animals. To conclude, our results suggest that the consequences of NMDA receptor modulation on learning and memory processes and sensorimotor functions may be functionally different or have distinct anatomical locations.

Adaptation, Psychological↗
PubMed2004

NF-kappaB p50-deficient mice show reduced anxiety-like behaviors in tests of exploratory drive and anxiety.

The ubiquitous transcription factor nuclear factor (NF)-kappaB plays a prominent role in regulation of inflammatory immune responses and in cell survival. Recently, it has been found to be active in neurons, and mice lacking NF-kappaB subunits p50 or p65 show deficits in specific cognitive tasks. Here we demonstrate a strikingly low level of anxiety-like behavior in the p50(-/-) mouse. In an open field, the mutant mice showed significantly less defecation, more rearing, and more time spent in the center compartment relative to wild type control mice. The p50(-/-) mice also spent more time investigating a novel object placed in the open field. On the elevated plus maze, p50(-/-) mice spent more time on the open arms and had increased numbers of open arm entries relative to wild type. In group housing conditions, they did not establish dominant-subordinate hierarchies, whereas wild type control animals did so, in part, by whisker barbering and conspecific allogrooming. In tests of general health, sensorimotor function, and daily activity on a circadian rhythm, p50(-/-) mice were normal. Thus, absence of the p50 subunit of the NF-kappaB transcription factor, which results in altered NF-kappaB transcriptional activity in cells throughout the body and brain, alters neuronal circuitry underlying manifestation of emotional behavior. The p50 subunit appears to play a role in normal expression of certain forms of anxiety.

Animals↗
PubMed2006

Cerebellar vermis involvement in cocaine-related behaviors.

Although the cerebellum is increasingly being viewed as a brain area involved in cognition, it typically is excluded from circuitry considered to mediate stimulant-associated behaviors since it is low in dopamine. Yet, the primate cerebellar vermis (lobules II-III and VIII-IX) has been reported to contain axonal dopamine transporter immunoreactivity (DAT-IR). We hypothesized that DAT-IR-containing vermis areas would be activated in cocaine abusers by cocaine-related cues and, in healthy humans, would accumulate DAT-selective ligands. We used BOLD fMRI to determine whether cocaine-related cues activated DAT-IR-enriched vermis regions in cocaine abusers and positron emission tomography imaging of healthy humans to determine whether the DAT-selective ligand [11C]altropane accumulated in those vermis regions. Cocaine-related cues selectively induced BOLD activation in lobules II-III and VIII-IX in cocaine users, and, at early time points after ligand administration, we found appreciable [11C]altropane accumulation in lobules VIII-IX, possibly indicating DAT presence in this region. These data suggest that parts of cerebellar vermis mediate cocaine's persisting and acute effects. In light of prior findings illustrating vermis connections to midbrain dopamine cell body regions, established roles for the vermis as a locus of sensorimotor integration and motor planning, and findings of increased vermis activation in substance abusers during reward-related and other cognitive tasks, we propose that the vermis be considered one of the structures involved in cocaine- and other incentive-related behaviors.

Adult↗
PubMed2003

Neurological dysfunctions versus regional infarction volume after focal ischemia in Mongolian gerbils.

BACKGROUND AND PURPOSE: With advances in the therapy of stroke at the postacute phase, the use of animal models for chronological and region-specific evaluation of neurological function has become increasingly important. Our aim was to test long-term behavioral dysfunction in gerbils after focal ischemia and to correlate the results with the regional distribution of infarction in the coordinating cortical regions. METHODS: Repetitive unilateral hemispheric ischemia (two 10-minute occlusions, 5-hour interval) was induced in Mongolian gerbils. The elevated body swing test (EBST), bilateral asymmetry test (BAT), and T-maze test were performed to assess asymmetrical motor behavior, somatosensory deficit, and spatial cognitive dysfunction during 4 weeks after ischemia. The results were correlated against the regional infarction volume of the primary motor, somatosensory, and primary visual cortices at 4 weeks after ischemia. RESULTS: In all postischemic gerbils, persistent sensorimotor and cognitive dysfunctions were detectable throughout the postischemic period. Histological examination revealed that a cortical zone of infarction surrounded the selective neuronal death in the ipsilateral cerebral hemisphere. The regional infarction volumes of the primary motor, somatosensory, and visual cortices were significantly correlated with the scores of the EBST, BAT, and T-maze test, respectively. These combinations had the highest regression coefficient of all pairs. CONCLUSIONS: Postischemic motor and somatosensory functions were significantly correlated with regional infarction volumes in the corresponding cortical regions. In gerbils, visual abnormality could be independently detected by the T-maze test. Such regional analyses of ischemic lesions would be useful for investigating the functional outcomes of stroke therapy.

Animals↗
PubMed1990

A region in the dorsolateral striatum of the rat exhibiting single-unit correlations with specific locomotor limb movements.

1. To examine the activity of single units in the lateral striatum of the awake rat with respect to sensorimotor function, 788 units were recorded during locomotion and passive testing. The focus of this report is on 138 units (18%) that fired in relation to sensorimotor activity of a single limb. The remaining units were related to other body parts (16%), to general body movement (38%), or were unresponsive (28%). 2. Firing rates of limb-related units were near zero during resting behavior but increased markedly during treadmill locomotion. Each of the 138 units exhibited a rhythmic pattern of discharge in phase with the locomotor step cycle. Passive testing revealed that 86/97 units tested (89%) responded to passive manipulation of a single limb, exhibiting increased firing rates. Of these, 77 (90%) were related to contralateral and 9 (10%) to ipsilateral limbs. Sixty-one units (71%) were related to a forelimb and 25 (29%) to a hindlimb. Of the 86 units responding to passive manipulation. 34/48 units tested (71%) also responded to cutaneous stimulation of the same limb but no other part of the body. 3. To study in greater detail the rhythmic unit discharges in phase with the locomotor step cycle, computer-synchronized videotape recordings were used to generate perimovement time histograms constructed around discrete locomotor movements of each limb (n = 17 units). Activity of each unit was shown to be restricted to a specific portion of a particular limb's step cycle. The majority of units discharged throughout (8 units) or during a portion of (3 units) the swing phase, whereas other units fired during a portion of stance (3 units), footfall (2 units), or foot off (1 unit). 1. The specificity of unit firing was further demonstrated by the finding that rhythmic discharges, related to discrete locomotor limb movements in the forward direction, were completely absent during spontaneous deviations such as backward or disrupted locomotion. 5. Units related to limb movement were located in the far lateral, especially the dorsolateral, subregion of the striatum. This subregion extend rostrocaudally from A-P +1.6 to -1.0 mm relative to bregma. No clear somatotopic organization was observed, but this issue requires further study. 6. These results show that functional representations of individual limbs can be demonstrated in the lateral striatum of the rat, within a subregion containing terminals of projections from somatic sensorimotor cortex.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1981

Effects of infraorbital nerve section on survival, growth, and suckling behaviors of developing rats.

Previous studies on sensory control of nursing in the rat have emphasized local olfactory cues. This study examined the role of tactile sensory processes by surgical section of the infraorbital nerve in rats at 17, 12, 7, and less than 1 day of postnatal age. All sectioned rats showed anesthesia of snout, upper lip, and vibrissal pads, and severe impairment of nipple attachment for at least the first day after denervation. Seven-day-old pups failed to recover, and all died after 3-6 days of relentless weight loss. Seventeen-day-old pups showed no weight loss after denervation if already weaned to solid food, but they lost weight for 3 days, and 25% failed to recover. Behavioral observations showed that denervated pups were activated by the mother's ventrum and probed for the nipple in the appropriate area but failed to focus head sweeping or licking and mouthing on the nipple itself and did not attach even when the nipple was inserted into the intact sensory areas of the mouth. Recovery after nerve section did not appear to be due to nerve regeneration. The data show that tactile cues are not necessary for normal nursing in the rat and suggest that important tactile sensorimotor adaptations may occur during the early and late phases of nursing.

Afferent Pathways↗
PubMed2002

Motor cortex activation is related to force of squeezing.

Primate studies have demonstrated that motor cortex neurons show increased activity with increased force of movement. In humans, this relationship has received little study during a power grip such as squeezing, and has previously only been evaluated across a narrow range of forces. Functional MRI was performed in eight healthy subjects who alternated between rest and right hand squeezing at one of three force levels. During scanning, motor performances were recorded using a dynamometer. At each force level, activation volume was measured within left sensorimotor cortex, right sensorimotor cortex, and a midline supplementary motor area. In left sensorimotor cortex, % signal change was also assessed. The range of force generated across the three force levels varied from 4.9 N to 276 N. In left sensorimotor cortex, activation volume increased significantly with greater force. The % signal change also increased with greater force and correlated closely with activation volume. In supplementary motor area, activation volume increased significantly with increasing force, but with greater intersubject variability. In right sensorimotor cortex, a trend for larger activation volumes with greater force did not reach significance. The laterality index, an expression of the relative degree of contralateral vs. ipsilateral sensorimotor cortex activation, did not change across the three force levels. Increased force of squeezing is associated with increased contralateral sensorimotor cortex and supplementary motor area activation. This relationship was found across the full spectrum of forces that the human hand is capable of generating. Use of a valid, reliable method for assessing motor behavior during functional MRI may be important to clinical applications.

Adult↗