Behavioral profile of amisulpride in agonistic encounters between male mice

Amisulpride is a substituted benzamide derivative that acts as a selective dopamine D2/D3 receptor antagonist. Although the anti‐aggressive properties of neuroleptic drugs are well known, the effects of amisulpride on agonistic interactions have not been explored, and there are no studies comparing acute and subchronic effects of this compound on aggression in rodents. In this study, we examined the action of amisulpride (5–25 mg/kg, i.p), administered acutely or subchronically for 10 days, on agonistic behavior elicited by isolation in male mice. Individually housed mice were exposed to anosmic "standard opponents" 30 min after drug administration, and the encounters were videotaped and evaluated using an ethologically based analysis. After acute treatment, amisulpride (5–20 mg/kg) exhibited an ethopharmacological profile characterized by a marked decrease of offensive behaviors (threat and attack) without an impairment of motor activity. By contrast, the anti‐aggressive action of the highest dose used (25 mg/kg) was accompanied by a weak increase of immobility. Body care was also significantly enhanced after treatment with the drug (20 and 25 mg/kg), emphasizing the involvement of dopaminergic receptors in this behavior. After subchronic treatment, no tolerance to amisulpride anti‐aggressive activity was observed. Overall, this behavioral profile is similar to that observed by other atypical neuroleptics. Aggr. Behav. 25:225–232, 1999. © 1999 Wiley‐Liss, Inc.     

Motor sequence learning in children with recovered and persistent developmental stuttering: preliminary findings

PurposePrevious studies have associated developmental stuttering with difficulty learning new motor skills. We investigated non-speech motor sequence learning in children with persistent developmental stuttering (CWS), children who have recovered from developmental stuttering (CRS) and typically developing controls (CON).MethodsOver the course of two days, participants completed the Multi-Finger Sequencing Task, consisting of repeated trials of a10-element sequence, interspersed with trials of random sequences of the same length. We evaluated motor sequence learning using accuracy and response synchrony, a timing measure for evaluation of sequencing timing. We examined error types as well as recognition and recall of the repeated sequences.ResultsCWS demonstrated lower performance accuracy than CON and CRS on the first day of the finger tapping experiment but improved to the performance level of CON and CRS on the second day. Response synchrony showed no overall difference among CWS, CRS and CON.Learning scores of repeated sequences did not differ from learning scores of random sequences in CWS, CRS and CON. CON and CRS demonstrated an adaptive strategy to response errors, whereas CWS maintained a high percentage of corrected errors for both days.ConclusionsOur study examined non-speech sequence learning across CWS, CRS and CON. Our preliminary findings support the idea that developmental stuttering is not associated with sequence learning per se but rather with general fine motor performance difficulties.     

Muscular fitness,motor competence,and processing speed in preschool children

ABSTRACT

The aim of this study was to examine the relationship between muscular fitness and motor competence and processing speed in preschool children. Eighty-four preschool-aged children were recruited and underwent assessments for muscular fitness (muscular endurance and power), motor competence, and then participated in an auditory oddball task. The findings showed that muscular fitness and motor competence were associated with shorter reaction times after controlling for confounding factors. These findings provide tentative support for a positive association between muscular fitness and motor competence and processing speed in preschool children.

abbreviations:

Reaction time (RT); Institutional Review Board (IRB); Basic Motor Ability Test-Revised (BMAT); Body mass index (BMI); Preschool Children Fitness Programme (PCFP); Intraclass correlation coefficients (ICC); Thinking Creatively in Action and Movement test (TCAM); Inter-stimulus interval (ISI); Insulin-like growth factor 1 (IGF-1); Brain-derived neurotrophic factor (BDNF)     

Ageing effects on the attention demands of walking

Attention demands of walking were determined in six male and six female young adults (mean 26.3 yr) and 12 gender-matched healthy, active older adults (mean 71.1 yr) using a dual task procedure with a reaction time (RT) secondary task. In three conditions an auditory stimulus, a visual stimulus and both stimuli (auditory/visual) were presented. Relative to no-walking baselines, increased RT was found in all conditions revealing an attentional cost of normal walking. When participants traversed the laboratory walkway and also positioned one of their feet within a target area on the ground, attention demands were greater than in unconstrained walking. In the targeting task, RTs to the visual stimulus were longer than for the auditory stimulus due to the interference associated with viewing both the stimulus monitor and the foot-target. Older participants' RTs in the visual and auditory/visual conditions, but not in the auditory condition, were significantly longer than for the young group in both walking tasks but RTs for young and older adults were not different in no-walking baseline trials. Inspection of mean RT functions at time intervals following gait initiation (0-3000 ms from the first step) suggested a fluctuating attentional cost of walking with increased demands associated with contingencies requiring step length regulation. The findings have applied significance in demonstrating the possibility of increased falls and pedestrian accident risk in older individuals in dual task situations such as road crossing.     

Antiaggressive and motor effects of the DA release inhibitor CGS 10746B

In the present study the effects of a wide range of doses of the dopamine release inhibitor CGS 10746B were evaluated in spontaneous activity and in aggressive behaviour using the paradigm of isolation‐induced aggression. The two higher doses (8 and 16 mg/kg) produced a decrease in spontaneous motor activity. Antiaggressive effects were observed after administration of doses from 4 mg/kg upwards. At this dose, CGS 10746B diminished threat and attack, and although an increase in immobility was observed, no impairment of other motor behaviours was presented. With higher doses, aggression was practically abolished but with a concomitant effect on many other behaviours. When animals were separated depending on their latency of attack, those that showed a long attack latency (LAL) presented a stronger response to 4 mg/kg than those that had a short attack latency (SAL), which were not affected in their aggression by this dose. We can conclude that presynaptic dopamine function is necessary for the normal expression of aggressive behaviours, since CGS 10746B reduces aggression at doses that do not affect spontaneous motor activity. Aggr. Behav. 27:382–390, 2001. © 2001 Wiley‐Liss, Inc.     

Visual-Motor Integration Problems in Low Birth Weight Infants

This paper represents a review of the research that focuses on a population of strong clinical interest on a national and international scale—infants born with low birth weight (LBW). Among the numerous developmental deficits commonly associated with this group, one of the most frequently cited problems is poor fine- and visual-motor integration. In addition to the direct perceptual-motor development concern, the literature provides a reasonable case that such deficits place this population at increased risk for subnormal academic performance and difficulties with specific daily living (self-help) activities. By assessing the infant at an early age and designing specific strategies for intervention, clinical psychologists can play a major role in improving fine- and visual-motor behavior in this population.     

Ocular motor indicators of executive dysfunction in fragile X and Turner syndromes

Fragile X and Turner syndromes are two X-chromosome-related disorders associated with executive function and visual spatial deficits. In the present study, we used ocular motor paradigms to examine evidence that disruption to different neurological pathways underlies these deficits. We tested 17 females with fragile X, 19 females with Turner syndrome, and 40 females with neither disorder who comprised the comparison group. Group differences emerged for both the fragile X and Turner syndrome groups, each relative to the comparison group: Females with fragile X had deficits in generating memory-guided saccades, predictive saccades, and saccades made in the overlap condition of a gap/overlap task. Females with Turner syndrome showed deficits in generating memory-guided saccades, but not during either the predictive saccade or gap/overlap task. Females with Turner syndrome, but not females with fragile X, showed deficits in visually guided saccades and anti-saccades. These findings indicate that different brain regions are affected in the two disorders, and suggest that different pathways lead to the similar cognitive phenotypes described for fragile X and Turner syndromes.     

Frequency and pattern of voluntary pedalling is influenced after one week of heavy strength training

Changes in voluntary rhythmic leg movement characteristics of freely chosen cadence (reflecting movement frequency) and tangential pedal force profile (reflecting movement pattern) were investigated during 4 weeks of (i) heavy hip extension strength training (HET, n = 9), (ii) heavy hip flexion strength training (HFT, n = 9), and (iii) no intervention (CON, n = 9). Training consisted of three 5RM–10RM sets per session, with two sessions/week. Submaximal ergometer cycling was performed before the training period (pretest) and after every week of training (test A1, A2, A3, and posttest). Strength increased by on average 25% in HET and 33% in HFT. Freely chosen cadence was only changed in HET, occurring already after 1 week of training. Thus, percentage reductions of cadence in HET at test A1, A2, A3, and posttest, with respect to the pretest value, amounted for maximally on average 17%, or 14 rpm, and were larger than the corresponding changes in CON (p = .037). Percentage increases in minimum tangential pedal force in HET at test A1, A2, A3, and posttest, with respect to the pretest value, were larger than the corresponding changes in CON (p = .024). Heavy hip flexion strength training did not cause such alterations.     

Left-hemisphere activation is associated with enhanced vocal pitch error detection in musicians with absolute pitch

The ability to process auditory feedback for vocal pitch control is crucial during speaking and singing. Previous studies have suggested that musicians with absolute pitch (AP) develop specialized left-hemisphere mechanisms for pitch processing. The present study adopted an auditory feedback pitch perturbation paradigm combined with ERP recordings to test the hypothesis whether the neural mechanisms of the left-hemisphere enhance vocal pitch error detection and control in AP musicians compared with relative pitch (RP) musicians and non-musicians (NM). Results showed a stronger N1 response to pitch-shifted voice feedback in the right-hemisphere for both AP and RP musicians compared with the NM group. However, the left-hemisphere P2 component activation was greater in AP and RP musicians compared with NMs and also for the AP compared with RP musicians. The NM group was slower in generating compensatory vocal reactions to feedback pitch perturbation compared with musicians, and they failed to re-adjust their vocal pitch after the feedback perturbation was removed. These findings suggest that in the earlier stages of cortical neural processing, the right hemisphere is more active in musicians for detecting pitch changes in voice feedback. In the later stages, the left-hemisphere is more active during the processing of auditory feedback for vocal motor control and seems to involve specialized mechanisms that facilitate pitch processing in the AP compared with RP musicians. These findings indicate that the left hemisphere mechanisms of AP ability are associated with improved auditory feedback pitch processing during vocal pitch control in tasks such as speaking or singing.     

Responsiveness and functional connectivity of the scene-sensitive retrosplenial complex in 7–11-year-old children

Brain imaging studies have identified two cortical areas, the parahippocampal place area (PPA) and the retrosplenial complex (RSC), that respond preferentially to the viewing of scenes. Contrary to the PPA, little is known about the functional maturation and cognitive control of the RSC. Here we used functional magnetic resonance imaging and tasks that required attention to scene (or face) images and suppression of face (or scene) images, respectively, to investigate task-dependent modulation of activity in the RSC and whole-brain functional connectivity (FC) of this area in 7–11-year-old children and young adults. We compared responsiveness of the RSC with that of the PPA. The RSC was selectively activated by scene images in both groups, albeit less than the PPA. Children modulated activity between the tasks similarly in the RSC and PPA, and to the same extent as adults in PPA, whereas adults modulated activity in the RSC less than in PPA. In children, the whole brain FC of the RSC was stronger in the Sf than Fs task between the left RSC and right fusiform gyrus. The between groups comparison suggested stronger FC in children than adults in the Sf task between the right RSC and the left inferior parietal lobule and intraparietal sulcus. Together the results suggest that the function of the RSC and the related networks undergo dynamic changes over the development from 7–11-year-old children to adulthood.