Cytoarchitecture and musculotopic organization of the facial motor nucleus in Cebus apella monkey

The architecture and musculotopic organization of the facial motor nucleus in the Cebus apella monkey (a New World primate) were investigated using histological techniques and a multiple labelling strategy, in which horseradish peroxidase‐conjugated neuroanatomical tracers (CTB‐HRP and WGA‐HRP) and fluorescent tracers were injected into individual facial muscles. The facial motor nucleus was formed by multipolar motoneurons and had an ovoid shape, with its rostrocaudal axis measuring on average 1875 µm. We divided the nucleus into four different subnuclei: medial, intermediate, dorsal and lateral. Retrograde labelling patterns revealed that individual muscles were innervated by longitudinal functional columns of motoneurons. The columns of the orbicularis oculi, zygomaticus, orbicularis oris, auricularis superior, buccinator and platysma muscles were located in the dorsal, intermediate, lateral, medial, lateral and intermediate subnuclei, respectively. However, the motoneuron columns of the levator labii superioris alaeque nasi muscle and frontalis muscle could not be associated with a specific subnucleus. The present results confirm previous studies regarding the musculotopic organization of the facial motor nucleus. However, we observed some particularities in terms of the relative size of each column in C. apella, which might be related to the functional and behavioral importance of each muscle in the particular context of this primate.     

Histological characterization of neurones innervating functionally different muscles of Locusta

The innervation of four functionally different muscles (subalar, remotor 1, remotor 2, pleuroalar), all served by the same nerve branch, was studied in both winged segments of the locust, Locusta migratoria. Several anatomical techniques were applied: With the cobalt backfill and silver intensification technique four cell types (motoneurone, dorsal unpaired median neurone, common inhibitory neurone, and small median neurone) were demonstrated. Serial sections enabled the morphology of the motoneurones to be described in more detail and in respect to a possible functional organization of the arborizations. A differential staining technique allowed us to stain various neurones in different colours in the same preparation. With this technique the anatomy of both the "rostral" and the "caudal" subalar motoneurones could be described in parallel, thus avoiding errors in comparison due to possible individual variations from preparation to preparation. Axon counts in the peripheral nerve branch enabled us to compile a list of the total innervation for each muscle. Results from other orthopterans are integrated and whether differences in the dendritic fields might be of functional significance is discussed.     

Magnetic Resonance Imaging Assessment of Abductor Muscles Shortly After Curved Periacetabular Osteotomy

BackgroundCurved periacetabular osteotomy (CPO) is performed via an anterior approach without detachment of the hip abductor muscles. This study aimed to evaluate the abductor muscle status shortly after CPO on magnetic resonance imaging (MRI).MethodsWe prospectively evaluated 38 hips in 38 patients 1 week and 3 months after CPO between October 2017 and July 2019. The status of the abductor muscles was assessed on MRI using the following criteria: grade 0, normal; grade I, strain/edema; grade II, partial tear; and grade III, complete tear. We also evaluated associations between muscle status and patients’ characteristics.ResultsOne week after CPO, the gluteus maximus was classified as grade 0 in all patients. The gluteus medius was grade 0 in 84.2% of patients and grade I in 15.8%. The gluteus minimus was grade I in 55.3% of patients and grade II in 44.7%. Three months after CPO, both the gluteus maximus and gluteus medius were grade 0 in all patients, while the gluteus minimus was still grade I in 47.4%. There were no significant differences between patients with a grade 0 and grade I gluteus minimus at 3 months after CPO in patients’ characteristics (age and body mass index) or clinical scores (Harris Hip Score and Japanese Orthopedics Association score).ConclusionBoth the gluteus minimus and medius showed abnormal appearances on MRI 1 week after CPO, whereas only the gluteus minimus showed abnormalities 3 months after CPO. This abductor muscle status did not affect the postoperative Harris Hip Score or Japanese Orthopedics Association score.     

Effects of myofascial release applied to neck muscles and craniocervical flexor training in patients with chronic myofascial TMD: A single arm study

ObjectiveTo evaluate the effects of myofascial trigger point release applied to superficial neck muscles and strengthening of the deep flexor muscles in subjects with myofascial temporomandibular disorders (mTMD).MethodsFourteen women (23.4 ± 3.32 years old) presenting with mTMD and trigger points (TrPs) in the sternocleidomastoid, suboccipital, and upper trapezius muscles were included in this study. They were evaluated on two occasions during a baseline period (3 weeks apart) with no intervention and a third time after a 5-weeks intervention protocol. Outcome measures included pressure pain threshold (PPT) over the masticatory muscles, mandibular function, orofacial pain intensity, maximum mouth opening, and the craniocervical flexion test. All women received 10 treatment sessions that included strain-counterstrain technique applied to TrPs found in the prior listed superficial neck muscles and stabilization exercise using a pressure biofeedback for the deep neck flexor muscles. One-way ANOVA or correspondent non-parametric tests as well as effects sizes were used to compare the outcomes at baseline and after the treatment.ResultsStatistically significant improvements were found in the PPT over left masseter and temporalis (p < 0.05) (mean difference (MD) of 0.50 and 0.42 kg/cm²), orofacial pain intensity (MD = −3.39 points), mandibular function (MD = −7.22 points) and performance of the deep cervical muscles (MD = 130.42 points) compared to baseline period. Effect sizes were moderate or large.ConclusionThe protocol intervention may have positive effects in patients with mTMD. However, studies with better methodological quality need to be performed to confirm those effects.Registrationensaiosclinicos.gov.br (RBR-7x828q);     

下肢肌肉功能模型应用软件的开发与应用

目的建立人体下肢肌肉功能的数学模型并编写相应的计算机软件,为人体运动过程中的下肢各肌肉力学描述及评估提供快速可靠的数据支持。方法利用现有的国人下肢肌肉附着点的三维坐标数据及其与体表骨性形态学参数的回归方程等相关研究成果,利用VisualC++6.0平台,编写下肢肌肉功能评定软件。结果软件系统可输出任意模拟姿态或实际运动过程中的下肢肌肉功能参数。结论本研究成果可从肌肉动力学层面来指导运动员的专项力量训练,提高运动成绩,也可应用于相关医学领域。     

Adductor pollicis. The missing interosseous

Summary This paper highlights the many similarities between the adductor pollicis and the palmar interossei. In particular it compares their anatomy, innervation and function. It suggests that adductor pollicis should be considered as the first palmar interosseous and that this view simplifies the teaching of hand anatomy and the tests of ulnar nerve function. Further support for the view that adductor pollicis is the thenar counterpart of the second, third and fourth palmar interossei is gained from studies of the literature on hand evolution, in particular published details of fossil records and dissection of primate hands.

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L'adducteur du pouce : l'interrosseux perdu

Résumé Cet article souligne les nombreuses similitudes qui existent entre le m. adducteur du pouce et le m. premier inter-osseux palmaire. Il compare en particulier l'anatomie l'innervation et la fonction de ces muscles. Le m. adducteur du pouce semble bien devoir être considéré comme le m. premier inter-osseux palmaire et ce point de vue simplifie l'enseignement de l'anatomie de la main ainsi que l'évaluation de la fonction du nerf ulnaire. Des arguments supplémentaires en faveur de l'hypothèse d'un m. adducteur du pouce qui serait la contre-partie thénarienne des second, troisème et quatrième mm. inter-osseux palmaires proviennent de l'étude de la littérature concernant la phylogénèse de la main et en particulier des résultats d'études portant sur les fossiles et les dissections de mains de primates.

     

Functional coupling of the stabilizing eye and head reflexes during horizontal and vertical linear motion in the cat

Summary The otolith contribution and otolith-visual interaction in eye and head stabilization were investigated in alert cats submitted to sinusoidal linear accelerations in three defined directions of space: up-down (Z motion), left-right (Y motion), and forward-back (X motion). Otolith stimulation alone was performed in total darkness with stimulus frequency varying from 0.05 to 1.39 Hz at a constant half peak-to-peak amplitude of 0.145 m (corresponding acceleration range 0.0014–1.13 g) Optokinetic stimuli were provided by sinusoidally moving a pseudorandom visual pattern in the Z and Y directions, using a similar half peak-to-peak amplitude (0.145 m, i.e., 16.1°) in the 0.025–1.39 Hz frequency domain (corresponding velocity range 2.5°–141°/s). Congruent otolith-visual interaction (costimulation, CS) was produced by moving the cat in front of the earth-stationary visual pattern, while conflicting interaction was obtained by suppressing all visual motion cues during linear motion (visual stabilization method, VS, with cat and visual pattern moving together, in phase). Electromyographic (EMG) activity of antagonist neck extensor (splenius capitis) and flexor (longus capitis) muscles as well as horizontal and vertical eye movements (electrooculography, EOG) were recorded in these different experimental conditions. Results showed that otolith-neck (ONR) and otolith-ocular (OOR) responses were produced during pure otolith stimulation with relatively weak stimuli (0.036 g) in all directions tested. Both EMG and EOG response gain slightly increased, while response phase lead decreased (with respect to stimulus velocity) as stimulus frequency increased in the range 0.25–1.39 Hz. Otolith contribution to compensatory eye and neck responses increased with stimulus frequency, leading to EMG and EOG responses, which oppose the imposed displacement more and more. But the otolith system alone remained unable to produce perfect compensatory responses, even at the highest frequency tested. In contrast, optokinetic stimuli in the Z and Y directions evoked consistent and compensatory eye movement responses (OKR) in a lower frequency range (0.025–0.25 Hz). Increasing stimulus frequency induced strong gain reduction and phase lag. Oculo-neck coupling or eye-head synergy was found during optokinetic stimulation in the Z and Y directions. It was characterized by bilateral activation of neck extensors and flexors during upward and downward eye movements, respectively, and by ipsilateral activation of neck muscles during horizontal eye movements. These visually-induced neck responses seemed related to eye velocity signals. Dynamic properties of neck and eye responses were significantly improved when both inputs were combined (CS). Near perfect compensatory eye movement and neck muscle responses closely related to stimulus velocity were observed over all frequencies tested, in the three directions defined. The present study indicates that eye-head coordination processes during linear motion are mainly dependent on the visual system at low frequencies (below 0.25 Hz), with close functional coupling of OKR and eye-head synergy. The otolith system basically works at higher stimulus frequencies and triggers Synergist OOR and ONR. However, both sensorimotor subsystems combine their dynamic properties to provide better eyehead coordination in an extended frequency range and, as evidenced under VS condition, visual and otolith inputs also contribute to eye and neck responses at high and low frequency, respectively. These general laws on functional coupling of the eye and head stabilizing reflexes during linear motion are valid in the three directions tested, even though the relative weight of visual and otolith inputs may vary according to motion direction and/or kinematics.     

Isovelocity investigation of the lengthening behaviour of the erector spinae muscles

The purpose of this study was to investigate the force-velocity (F/) relationship for the erector spinae muscles in submaximal activation movements, with particular attention to their response during lengthening movements and at lower shortening contraction velocities. Dynamic models that predict lower back muscle forces require reasonable representations of the modulating effect of instantaneous velocity. Ten males were observed performing trunk flexion and extension in the sagittal plane under constant load. Contraction velocities were measured as the first derivative from a devise sensitive to changes in spine curvature, and controlled by a visual feedback system while a constant load was applied through a chest harness. The erector spinae exhibited a yielding phenomenon which causes an abrupt drop in force during constant velocity stretching under constant, submaximal, stimulation. The findings were consistent with previous isovelocity muscle lengthening experiments. Yielding appeared dependent on the level of load/activation supporting the theory of a state-variableF/ relationship. The eccentric behaviour of the lower erectors (L3) seemed independent of velocity and length, while that of the upper erectors (T9) showed a dependence on length. At lower concentric velocities, concavity in torque-velocity curves was noted after a threshold velocity. The findings of this study strongly reinforce the notion that theF/ length relationship is not a continuous hyperbolic relationship during muscle shortening and that the commonly modelled force augmentation effect of lengthening is incorrect, at least for submaximal activation of the extensors of the lower back.     

PNS单体Rb_l对豚鼠心脏乳头肌动作电位和收缩力的影响

目的 :了解PNS单体Rbl对豚鼠心脏乳头肌动作电位和收缩力的影响。方法 :运用带有动作电位和收缩力分析软件控制的细胞内微电极技术 ,研究了三七皂苷 (PNS)单体Rbl对豚鼠正常心脏乳头肌动作电位 (AP)各特征参数及收缩力 (FC)的影响。结果 :Rb1 1 0～ 30 μmol·L- 1 分别使APD 2 0 ,APD 90明显缩短 ,FC显著下降 (P<0 .0 1 ,n =5) ,并可降低高钾诱发的豚鼠乳头肌慢反应动作电位的动作电位幅值 (APA)及零相最大上升速率(Vmax) (P <0 .0 5 ,n =5)。但对静息电位 (RP) ,APA ,Vmax及AP的超射值 (OS)无明显影响 (P >0 .0 5 ,n =5)。另外 ,Rbl可浓度依赖性地抑制乳头肌收缩力 (FC) ,RP ,APA不随Rbl剂量增加而产生明显变化 ,呈典型的兴奋 收缩脱藕联。结论 :其效应可能通过阻滞钙通道而产生     

4种氨基甙类抗生素对膈肌和四肢肌肉的松弛作用

目的　探讨氨基甙类抗生素—阿贝卡星 (arbekacin ,ABK) ,阿司霉素 (astromicin ,ASTM) ,异帕咪星 (isepamicin ,ISP)和奈替咪星 (netilmicin ,NTL)在家兔的膈肌 ,前胫骨肌和比目鱼肌的神经肌肉抑制作用。方法　将 2 4只家兔平均分成 4组 ,戊巴比妥静脉麻醉下分别游离膈神经 -膈肌 ,胫神经 -前胫骨肌和腓总神经 -比目鱼肌 ,然后在膈肌表面和肢体肌远端肌腱固定连接肌张力换能测定装置以及在上述神经固定神经刺激电极 ,给予频率为 0 1Hz ,持续 0 1ms ,间隔 10s的超强电刺激。采用累积剂量给药法分别静脉注射以上被验 4种抗生素 ,记录刺激神经所诱发的肌肉等张颤搐强度 ,评价抗生素在 3种肌群不同神经肌肉抑制作用。结果　 4种抗生素在以上 3种骨骼肌肌群均表现不同程度的抑制作用 ,在初期剂量给药时 ,膈肌对药物的敏感性较明显 ,比目鱼肌表现相对最弱。抗生素作用于这 3种肌群的ED50 值大小顺序为比目鱼肌 >前胫骨肌 >膈肌和ED95值大小顺序为比目鱼肌 >膈肌 >前胫骨肌。抗生素在前胫骨肌和比目鱼肌的ED50 值约分别为膈肌的 1 5和 2 7倍。 4种抗生素间神经肌肉抑制作用强度顺序为NTL >ABK >ASTM >ISP。这些抗生素引起的神经肌肉抑制作用可以被新斯的明和钙剂所拮抗。结论　 4种氨基甙类抗生素在膈肌相