***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: INTRODUCTION We used transcranial magnetic stimulation ( TMS ) to investigate 3 weeks of unilateral leg strength training on ipsilateral motor cortex ( iM1 ) excitability , and short-latency intracortical inhibition ( SICI ) . METHODS Right leg dominant participants ( n = 14 ) were r and omly divided into either a  strength training ( ST )  or  control group . The ST group completed 9 training sessions ( 4 sets of 6 to 8 repetitions of single right leg squats ) . RESULTS We observed a 41 % increase in right leg strength , and a 35 % increase in strength of the untrained left leg ( P < 0.01 ) . There was a significant increase in motor evoked potential ( MEP ) amplitude recruitment curve for the untrained left leg ( P < 0.01 ) . SICI of the iM1 decreased by 21 % for the untrained left leg ( P < 0.01 ) . CONCLUSIONS The findings provide evidence for corticomotor adaptation for unilateral leg strength training within the iM1 that is modulated by changes in interhemispheric inhibition Purpose To test whether long-term cortical adaptations occur bilaterally following  chronic unilateral training  with a simple motor task . Methods Participants ( n = 34 ) were r and omly allocated to a training or control groups . Only the former completed a 4-week maximal-intensity isometric training of the right first dorsal interosseus muscle through key pinching . Maximal strength was assessed bilaterally in four different movements progressively less similar to the training task : key , tip and tripod pinches , and h and grip . Transcranial magnetic stimulation was used to probe , in the left and right primary h and motor cortices , a number of st and ard tests of cortical excitability , including thresholds , intra-cortical inhibition and facilitation , transcallosal inhibition , and sensory-motor integration . Results Training increased strength in the trained h and , but only for the tasks specifically involving the trained muscle ( key + 8.5 % ; p < 0.0005 ; tip + 7.2 % ; p = 0.02 ) . However , the effect size was small and below the cutoff for meaningful change . H and grip and tripod pinch were instead unaffected . There was a similar improvement in strength in the untrained h and , i.e. , a cross-education effect ( key + 6.4 % ; p = 0.02 ; tip + 4.7 % ; p = 0.007 ) . Despite these changes in strength , no significant variation was observed in any of the neurophysiological parameters describing cortico-spinal and intra-cortical excitability , inter-hemispheric inhibition , and cortical sensory-motor integration . Conclusions A 4-week maximal-intensity unilateral training induced bilaterally spatial- and task-specific strength gains , which were not associated to direct or crossed cortical adaptations . The observed long-term stability of neurophysiological parameters might result from homeostatic plasticity phenomena , aim ed at restoring the physiological inter-hemispheric balance of neural activity levels perturbed by the exercise . Trial registration number Clinical Trials.gov identifier NCT02010398 Behavioural studies indicate that a newly acquired motor skill is rapidly consoli date d from an initially unstable state to a more stable state , whereas neuroimaging studies demonstrate that the brain engages new regions for performance of the task as a result of this consolidation . However , it is not known where a new skill is retained and processed before it is firmly consoli date d. Some early aspects of motor skill acquisition involve the primary motor cortex ( M1 ) , but the nature of that involvement is unclear . We tested the possibility that the human M1 is essential to early motor consolidation . We monitored changes in elementary motor behaviour while subjects practised fast finger movements  that rapidly improved in movement acceleration and muscle force generation . Here we show that low-frequency , repetitive transcranial magnetic stimulation of M1 but not other brain areas specifically disrupted the retention of the behavioural improvement , but did not affect basal motor behaviour , task performance , motor learning by subsequent practice , or recall of the newly acquired motor skill . These findings indicate that the human M1 is specifically engaged during the early stage of motor consolidation This study employed longitudinal measures of evoked spinal reflex responses ( Hoffman reflex , V wave ) to investigate changes in the activation of muscle and to determine if there are " linked " neural adaptations in the motor pathway following isometric resistance training .  Twenty healthy , sedentary males were r and omly assigned to either the trained ( n = 10 ) or control group ( n = 10 ) . The training protocol consisted of 12 sessions of isometric resistance training of the plantar flexor muscles over a 4-wk period . All subjects were tested prior to and after the 4-wk period . To estimate changes in spinal excitability , soleus Hoffman ( H ) reflex and M wave recruitment curves were produced at rest and during submaximal contractions . Recruitment curves were analyzed using the slope method ( Hslp/Mslp ) . Modulation of efferent neural drive was assessed through evoked V wave responses ( V/Mmax ) at 50 , 75 , and 100 % maximal voluntary contraction ( MVC ) . After 4 weeks , MVC torque increased 20.0 + /- 13.9 % ( mean + /- SD ) in the trained group . The increase in MVC was accompanied by significant increases in the rate of torque development ( 42.5 + /- 13.3 % ) , the soleus surface electromyogram ( 60.7 + /- 30.8 % ) , voluntary activation ( 2.8 + /- 0.1 % ) , and the rate of activation ( 48.7 + /- 24.3 % ) . Hslp/Mslp was not altered by training ; however , V/Mmax increased 57.3 + /- 34.2 % during MVC . These results suggest that increases in MVC observed in the first few days of isometric resistance training can be accounted for by an increase in the rate of activation at the onset of muscle contraction . Augmentation of muscle activation may be due to increased volitional drive from supraspinal centers Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more The purpose of this study was to investigate age-related differences in short-term training adaptations in cortical excitability and inhibition . Thirty young ( 21.9 ± 3.1 years ) and 30 older ( 72.9 ± 4.6 years ) individuals participated in the study . Each participant was r and omly assigned to a control ( n = 30 ) or a resistance training ( n = 30 ) group , with equal numbers of young and older subjects in each group . Participants completed 2 days of testing , separated by 2 weeks during which time the training group participated in resistance training of the ankle dorsiflexor muscles three times per week . During each testing session , transcranial magnetic stimulation was used to generate motor evoked potentials ( MEPs ) and silent periods in the tibialis anterior . Hoffmann reflexes ( H-reflexes ) and compound muscle action potentials ( M-waves ) were also evoked via electrical stimulation of the peroneal nerve . At baseline , young subjects had higher maximum voluntary contraction ( MVC ) force ( p = 0.002 ) , larger M-wave amplitude ( p < 0.001 ) , and longer duration silent periods ( p = 0.01 ) than older individuals , with no differences in the maximal amplitude of the MEP ( p = 0.23 ) or H-reflex ( p = 0.57 ) . In the trained group , MVC increased in both young ( 17.4 % ) and older ( 19.8 % ) participants ( p < 0.001 ) , and the duration of the silent period decreased by ~15 and 12 ms , respectively ( p < 0.001 ) . Training did not significantly impact MEP ( p = 0.69 ) or H-reflex amplitudes ( p = 0.38 ) . There were no significant changes in any measures in the control group ( p ≥ 0.19 ) across the two testing sessions . These results indicate that a reduction in cortical inhibition may be an important neural adaptation in response to training in both young and older adults OBJECTIVE : To test the feasibility of creating a valid and reliable checklist with the following features : appropriate for assessing both r and omised and non-r and omised studies ; provision of both an overall score for study quality and a profile of scores not only for the quality of reporting , internal validity ( bias and confounding ) and power , but also for external validity . DESIGN : A pilot version was first developed , based on epidemiological principles , review s , and existing checklists for r and omised studies . Face and content validity were assessed by three experienced review ers and reliability was determined using two raters assessing 10 r and omised and 10 non-r and omised studies . Using different raters , the checklist was revised and tested for internal consistency ( Kuder-Richardson 20 ) , test-retest and inter-rater reliability ( Spearman correlation coefficient and sign rank test ; kappa statistics ) , criterion validity , and respondent burden . MAIN RESULTS : The performance of the checklist improved considerably after revision of a pilot version . The Quality Index had high internal consistency ( KR-20 : 0.89 ) as did the subscales apart from external validity ( KR-20 : 0.54 ) . Test-retest ( r 0.88 ) and inter-rater ( r 0.75 ) reliability of the Quality Index were good . Reliability of the subscales varied from good ( bias ) to poor ( external validity ) . The Quality Index correlated highly with an existing , established instrument for assessing r and omised studies ( r 0.90 ) . There was little difference between its performance with non-r and omised and with r and omised studies . Raters took about 20 minutes to assess each paper ( range 10 to 45 minutes ) . CONCLUSIONS : This study has shown that it is feasible to develop a checklist that can be used to assess the method ological quality not only of r and omised controlled trials but also non-r and omised studies . It has also shown that it is possible to produce a checklist that provides a profile of the paper , alerting review ers to its particular method ological strengths and weaknesses . Further work is required to improve the checklist and the training of raters in the assessment of external validity The present study has investigated the long-term changes in the organisation of the corticomotor projection to the h and in a group of subjects who had sustained a subcortical hemispheric stroke up to 15 years previously and had subsequently recovered normal or near-normal motor function .  Transcranial magnetic cortical stimulation ( TMCS ) was employed to map the topography of the primary corticomotor projection to the h and and to obtain measures of cortical motor threshold , long-latency intracortical inhibition and corticospinal conduction . Changes in motor threshold and in motor-evoked potential ( MEP ) amplitude and latency in keeping with persisting impairment of conduction in the corticospinal pathway were still present in the majority of subjects , whereas the duration of the post-MEP silent period , reflecting the strength of long-latency intracortical inhibition , was usually normal . Topographic shifts in the corticomotor representation relative to the unaffected side were found in the majority of subjects . In some the shifts were in the mediolateral axis suggesting reorganisation within the primary motor cortex , while in the others anteroposterior shifts were present in keeping with recruitment of premotor or post central cortex . The present findings indicate that changes in the physiological properties of the corticomotor projection to the h and are frequently present in subjects who have recovered motor function after a subcortical stroke and may persist indefinitely . We postulate that these changes are the result of reorganisation at cortical level and that cortical reorganisation is one of the processes which contribute to motor recovery after a subcortical lesion and which may compensate for persisting impairment of conduction in the corticospinal pathway The purpose of this study was to investigate the effects of 4-week ( 16 sessions ) unilateral , maximal isometric strength training on contralateral neural adaptations . Subjects were r and omised to a strength training group ( TG , n = 15 ) or to a control group ( CG , n = 11 ) . Both legs of both groups were tested for plantar flexion maximum voluntary isometric contractions ( MVCs ) , surface electromyogram ( EMG ) , H-reflexes and V-waves in the soleus ( SOL ) and gastrocnemius medialis ( GM ) superimposed during MVC and normalised by the M-wave ( EMG/MSUP , HSUP/MSUP , V/MSUP , respectively ) , before and after the training period . For the untrained leg , the TG increased compared to the CG for MVC torque ( 33 % , P < 0.01 ) , SOL EMG/MSUP ( 32 % , P < 0.05 ) and SOL V/MSUP ( 24 % , P < 0.05 ) . For the trained leg , the TG increased compared to the CG for MVC torque ( 40 % , P < 0.01 ) , EMG/MSUP ( SOL : 38 % , P < 0.05 ; GM : 60 % , P < 0.05 ) and SOL V/MSUP ( 72 % , P < 0.01 ) . HSUP/MSUP remained unchanged for both limbs . No changes occurred in the CG . These results reinforce the concept that enhanced neural drive to the contralateral agonist muscles contributes to cross-education of strength Paired-pulse transcranial magnetic stimulation ( TMS ) was used to assess the effectiveness of intracortical inhibition ( ICI ) acting on corticospinal neurons controlling three intrinsic h and 
    Output:
    
In untrained healthy participants , the corticospinal response to strength training is characterised by reduced intracortical inhibition and cortical silent period duration , rather than changes in corticospinal excitability .
These data demonstrate that strength training targets intracortical inhibitory networks within the primary motor cortex ( M1 ) and corticospinal pathway , characterising an important neural adaptation to strength training