Longus Capitis Research Articles

Gravity load related asymmetries in the sagittal vestibulo-collic reflex.

EMG recordings of the neck muscles (biventer cervicis, complexus, splenius, longus capitis) of decerebrate cats were obtained during pitch and roll stimulations (sinusoidal stimulation: 30 degrees p-p amplitude, 0.2 Hz frequency). Most of the EMG responses to pitch showed activation peaks leading the position stimuli by 56 degrees and inhibition peaks leading by 11 degrees. Conversely, in response to roll the activation peak led by 16 degrees and the inhibition peak by 10 degrees. The activation peaks of the pitch responses were, thus, more asymmetric and more leading than those of the roll responses. Consequently, the harmonic distortion coefficient was significantly higher in pitch than in roll. Moreover, when the vertical semicircular canals were activated in absence of otolithic modulation, the pitch and roll responses maintained the same difference in timing observed in the presence of otolithic coactivation. It appeared that the simultaneous stimulation of both anterior semicircular canals (pitch) induces a greater lead than that of combined anterior and posterior canals (roll). Thus the timing of neck muscle responses to vestibular stimulation depends on the pair of activated vertical semicircular canals.

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

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 degrees) in the 0.025-1.39 Hz frequency domain (corresponding velocity range 2.5 degrees-141 degrees/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 (electro-oculography, 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).(ABSTRACT TRUNCATED AT 400 WORDS)

Ｔｏｒｎｗａｌｄｔ氏病例

Although persistence of the bursa pharyngea is observed in 4% of human adults, it is usually asymptomatic without inflammation. To date, there have been 10 reports of Tornwaldt's disease in Japan. In some of these reports, the authors confused the name of disease, so the actual number of cases of true Tornwaldt's disease is smaller. Our patient with Tornwaldt's disease is reported because of the rarity of the condition. A 41-year-old man complained of occipital and temporal headache with symptoms similar to cervical vertigo. Horizontal nystagmus was seen in suspending and rotaing head positions. A 1.5cm diameter round mass covered with slightly injected mucosa was present in the midline of the posterior nasopharyngeal wall. MRI revealed a well-defined oval cyst between the nasopharyngeal mucosa and the vertebrae. In the coronal image, the cyst was located in the midline between the longus capitis muscles, and in the sagittal image, the cyst had a tear-drop shape. The cystic mass was removed by a trans-palatal approach using a contact Nd-YAG laser. Histological examination revealed a cyst lined with ciliated columnar epithelium and the presence of numerous inflammatory cells. The patient was relieved of his symptoms 1 week after surgery. We considered that the cervical vertigo-like symptoms were caused by irritation of the sympathetic plexus surrounding the basilar artery induced by inflammation of the cyst, and that MR imaging was very useful in the diagnosis of Tornwaldt's disease.

Torque vectors of neck muscles in the cat

Anatomical texts describe the neck musculature without measurements of muscle locations or quantitative estimates of pulling actions (torques). This study is based on measurements in stereotaxic coordinates of cat neck muscle origins and insertions, and neck intervertebral rotation axes. Torque vectors in three dimensions were calculated for 14 pairs of dorsal and ventral muscles that insert on the skull or first cervical vertebra. Predicted torque vectors were in general agreement with qualitative statements in the literature. Biventer cervicis and the rectus capitis major, medius, and minor muscles act mainly to raise the head, and longus capitis acts almost exclusively to lower the head. Longissimus capitis, sternomastoid, and cleidomastoid act mainly to roll the head. Complexus acts about equally to raise the head and rool it. Splenius and occipitoscapularis have torque in all three coordinate directions. Torques were altered by changing the pitch of the head with respect to the neck. The calculated neck muscle torques did not correspond to previously reported directions of neck muscle excitation during the vestibulocollic reflex. The neck musculature appears to be a complex, multidimensional system that presents interesting problems in motor control.

Axonal trajectories of inhibitory vestibulocollic neurons activated by the anterior semicircular canal nerve and their synaptic effects on neck motoneurons in the cat

Somatic location, axonal trajectories and synaptic effects of inhibitory vestibulocollic neurons which were activated by selective stimulation of the anterior semicircular canal nerve (ACN) were studied in the anesthetized cat. ACN stimulation evoked disynaptic inhibitory postsynaptic potentials (IPSPs) in neck flexor motoneurons. This was seen in all the (64/64) tested motoneurons innervating the ipsilateral (i-) longus capitis (LC) and the i-sternocleidomastoideus (SCM) muscles and in 86% (38/44) of the motoneurons innervating the contralateral (c-) LC muscle. The inhibitory relay neurons, identified by orthodromic and antidromic responses to stimulation of the ACN and the i- and c-LC motoneuron pools, were classified as VCi (vestibulocollic neurons sending an axon to the i-LC motoneuron pool) and VCc (vestibulocollic neurons sending an axon to the c-LC motoneuron pool) neurons. Neither VCi nor VCc neurons were activated antidromically by localized stimulation of the ascending medial longitudinal fasciculus (asc. MLF) or the 3rd nuclei. They were located in the medial, descending and ventral lateral vestibular nuclei. It was also observed that VCi neurons produced unitary IPSPs in i-LC and i-SCM motoneurons in the C1 segment. Inhibitory synapses were estimated to be on the cell somata and/or the proximal dendrites of the motoneurons.

Electrophysiological study of ipsilateral vestibulo-collic reflex by the posterior semicircular canal stimulation

In 12 anesthetized cats, the posterior semicircular canal nerve (PCN) stimulation evoked disynaptic EPSPs (excitatory postsynaptic potentials) in the ipsilateral neck flexor motoneurons innervating longus capitis muscles in the C1 and C2 segment (i-C1LCmn and i-C2LCmn). The mean latency and maximum amplitude of the EPSPs in the i-C1LCmn and i-C2LCmn were 1.8 and 1.9 ms, and 340 and 350 microV, respectively. Concerning the latency and amplitude of the EPSPs, there were no differences in the i-C1LCmn and i-C2LCmn. The unit activities of 9 PCN-activated vestibulo-collic neurons sending axon to the ipsilateral motoneuron pool of longus capitis muscles in the C2 segment (i-C2LCmnp) were also observed. These neurons were activated orthodromically from the PCN stimulation with latencies of 1.3ms (mean) and with latencies of 1.2ms from the i-C2LCmnp stimulation antidromically. The cell body of these vestibulo-collic neurons located in the ventrolateral part of the lateral nucleus.

Axonal trajectories of posterior canal-activated secondary vestibular neurons and their coactivation of extraocular and neck flexor motoneurons in the cat.

Unit activities of 148 secondary vestibular neurons related to the posterior semicircular canal were recorded extracellularly in anesthetized cats. Axonal projections of these neurons were examined by their antidromic responses to stimulation of the excitatory target motoneurons of the contralateral (c-) inferior rectus muscle (IR) and bilateral (bi-) motoneuron pools of longus capitis muscles, neck flexors, in the C1 segment (C1LC). The neurons were classified into 4 groups according to their axonal projections. The first group of neurons, termed vestibulo-oculo-collic (VOC) neurons, sent axon collaterals both to the c-IR motoneuron pool and to the c-C1LC motoneuron pool. The majority of them (72%) were located in the descending nucleus. The second group of neurons were termed vestibuloocular (VO) neurons and sent their axons to the c-IR motoneuron pool but not to the cervical cord. Most of them (86%) were located in the medial nucleus. The third group of neurons, termed vestibulo-collic (contralateral) (VCc) neurons, sent axons to the c-C1LC motoneuron pool via the contralateral ventral funiculus but not to the oculomotor nuclei. They were mostly (75%) found in the descending nucleus. The last group of neurons were vestibulo-collic (ipsilateral) (VCi) neurons, which gave off axons to the ipsilateral (i-) C1LC motoneuron pool via the ipsilateral ventral funiculus but not to the oculomotor nuclei. One of them also sent an axon collateral to the c-C1LC motoneuron pool. The majority of them (74%) were located in the ventral part of the lateral nucleus. It was also observed in some of the VOC and VCi neurons that they produced unitary EPSPs in the c-C1LC and i-C1LC motoneurons, respectively. Their synaptic sites were estimated to be on the cell somata and/or proximal dendrites of the motoneurons.

Muscle spindle distribution of masticatory and prevertebral muscles with special reference to histological properties of pouch and biological significance in red kangaroo, Macropus rufus

The masticatory and prevertebral muscles of two embryos and four young including a newborn and the pouch of two mothers of the red kangaroo were examined microscopically. Furthermore, four older young of the red kangaroo were examined macroscopically to define the tooth eruption. The results obtained are as follows: 1. The initial muscle spindles are already observed in the prevertebral muscles of the newborn young of 21 mm in cranio-rump length (CRL), the number of spindles being 223 (right side) -110 (left side) in the longus capitis, 81 (r) -70 (1) in the longus colli, 31 (r) -39 (1) in the rectus capitis lateralis and 5 (r) -9 (1) in the rectus capitis anterioris. 2. The initial muscle spindles are observed in the masticatory muscles of the young of 68 mm in CRL and 28 g in body weight, which is much delayed than in the prevertebral muscles; the number of spindles being 33 (right) - 46 (left) in the masseter and 173 (r) - 187 (1) i n the temporal muscle. 3. The medial and lateral pterygoid muscles are devoid of the muscle spindles. The jaw opening muscles are also devoid of them. 4. In the frontal incisors there is seen the beginning of calcification of the dentine and enamel and in the molars there is seen the beginning of the dentinal calcification at the cuspal pulp in the older young of 125 mm in CRL and 86 g in body weight. 5. In the skin with less hair lining the inner surface of the pouch, abundant large sweat glands are well observed, especially surrounding the basal region of the nipple and in the pleat formation of the skin. 6. The lactiferous mammary gland is enlarged, the lobules being divided by the interlobular muscle fiber tissue and enwrapped by the muscular capsule. The milk is squirted by the glandular muscle contraction from the gland to the nipple, to which the baby attaches itself. 7. The musculature of the pouch wall is developed to form the sphincter muscle of the pouch orifice. The sphincter muscle would play an important role in conditioning the optimum temperature and moisture of the pouch for the naked baby inside the pouch. 8. The apocrine perfume would play an important role in guiding the blind baby on the journey to the pouch after birth and the apocrine product would also take an important part in maintaining the optimum humidity of the pouch to accommodate the baby. 9. During the long period of stay in the pouch, the masticatory and locomotive systems and their neuromuscular mechanism related to the herbivorous mastication become fully established and then the young leaves the pouch to feed on the animal's proper diet. The pouch is like an incubator for the immature baby.

Spatial and temporal response properties of the vestibulocollic reflex in decerebrate cats.

Vestibulocollic reflex responses of several neck muscles in decerebrate cats were studied during angular rotations of the whole body in a large number of vertical and horizontal rotation planes, at frequencies from 0.07 to 1.6 Hz. Vestibulocollic responses were compared to eye muscle and forelimb muscle vestibular responses. Electromyographic activity was recorded by fine wires inserted in biventer cervicis, complexus, longus capitis, obliquus capitis inferior, occipitoscapularis, rectus capitis major, splenius, lateral rectus, and triceps brachii. At frequencies of approximately 0.5 Hz and above, neck muscle electromyographic response gains were sinusoidal functions of stimulus orientation within a set of vertical or horizontal planes, and a muscle's response phase remained constant across rotation planes, or reversed by 180 degrees. Response patterns at high frequencies were consistent with vestibulocollic reflex activation by semicircular canals through brain circuitry that modifies canal dynamics. At frequencies of approximately 0.5 Hz and above, the stimulus orientation in which a given neck muscle's response was maximal remained nearly constant across frequencies. Thus, we used responses to rotations at high frequencies to calculate axes of maximal response of each muscle in three-dimensional space. Lateral rectus, obliquus, and to a lesser extent, splenius and longus capitus were activated predominantly by horizontal rotations. Biventer was activated predominantly by pitch, triceps predominantly by roll, and complexus, occipitoscapularis, and rectus major significantly excited by rotations in all three coordinate planes. In some cases, at frequencies less than 0.5 Hz, neck muscle response phase varied depending on the vertical plane in which the cat was rotated, and the optimal response plane was poorly defined and varied with frequency. These responses indicated that, at some frequencies, neck muscle activity can result from summation of inputs with differing spatial orientation and dynamics (spatial-temporal convergence). Differences between responses to vertical and horizontal rotations suggested that low-frequency spatial-temporal convergence behavior of the vestibulocollic reflex during vertical rotations was due to convergent semicircular canal and otolith receptor inputs.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent projections from the rat longus capitis muscle studied by transganglionic transport of HRP.

Using the method of transganglionic transport of horseradish peroxidase (HRP) according to Mesulam (1978), the course and central terminations of the afferents from the longus capitis muscle were studied in the rat. Application of HRP to the cut muscle nerves was followed by heavy labeling of a considerable number of cell bodies of different sizes in the spinal ganglia C2 and C3. The labeled central processes follow two distinct main routes: one to the external cuneate nucleus, which is known to project ipsilaterally to the cerebellum, the other to the central cervical nucleus (CCN) of the spinal cord. The latter nucleus contains dense arborizations and terminals of muscle afferents in close relationship to medium sized cells which project contralaterally to the cerebellum. This could be shown in double labeling experiments with HRP as a tracer for primary afferents and Nuclear yellow for the cerebellar pathway. The labeled area of CCN extends from the fourth cervical segment up to the medulla oblongata where it lies laterally adjacent to the hypoglossal nucleus, though clearly separated from the latter. In the cervical part of CCN, dendrites of neck muscle motoneurons arborize within the area of afferent terminals. Besides the external cuneate and the central cervical nuclei, afferent projections were seen in lamina X, partly in close contact with the central canal, and in more lateral areas of lamina VII. In contrast to results from studies on other neck muscles, no reaction product was observed in dorsal horn laminae I-VI.

Morphology and function of the feeding apparatus in Dermophis mexicanus (Amphibia: Gymnophiona)

The morphology and mechanics of feeding in Dermophis mexicanus were studied using descriptive anatomical, cinematographic and electromyographic approaches. The lower jaw has a retroarticular process extending one-third of the total jaw length, and an articulation that restricts anteroposterior movements. Muscles from three anatomically distinct sites, the temporal fossa, the lateral surface of the neck, and the subvertebral region, act to execute the bite during feeding on earthworms. Muscles in the first of these sites are comparable to the jaw adductors of other vertebrates, while those in the second two represent morphological and functional departures. The large interhyoideus muscle and the elongate retroarticular process are modified to function in jaw closing. The longus capitis muscles appear to act to depress the cranium at the cranio-vertebral joint, a motion that occurs simultaneously with maximum jaw closing. The latter two muscles appear to have greater importance for feeding in Dermophis than do the temporal adductors, and the evolution of this specialized arrangement may be related to the demands for a reduced cross-sectional area of the head in these burrowing vertebrates.

Musculi longus capitis et splenius der Ratte und innervierende Motoneurone

The nuclei for the nerves of a dorsal (m. splenius) and a ventral (m. longus capitis) neck muscle of the rat were retrogradely labeled by applying horseradish peroxidase (HRP) to the respective cut muscle nerves. Motoneurons of both muscles were analyzed for their localization, diameter of perikarya, and area of dendritic arborization. The nucleus of m. longus capitis is situated dorsomedially, the nucleus of m. splenius ventromedially within the ventral horn. Thus, the relative positions of the two nuclei are inverse to those of their muscles, with the more ventral nucleus innervating the more dorsal muscle.

Identification of muscle afferents which activate interneurons in the intermediate nucleus.

Identification of muscle afferents which activate interneurons in the intermediate nucleus.M E Lucas, and W D WillisM E Lucas, and W D WillisPublished Online:01 Mar 1974https://doi.org/10.1152/jn.1974.37.2.282MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByPeripheral inflammation is associated with increased glutamic acid decarboxylase immunoreactivity in the rat spinal cordNeuroscience Letters, Vol. 128, No. 2Presynaptic inhibition of muscle spindle and tendon organ afferents in the mammalian spinal cordTrends in Neurosciences, Vol. 13, No. 12PAD patterns of physiologically identified afferent fibres from the medial gastrocnemius muscleExperimental Brain Research, Vol. 71, No. 3Detection of synchrony in the discharge of a population of neurons. II. Implementation and sensitivity of a synchronization indexJournal of Neuroscience Methods, Vol. 13, No. 1Electrophysiological characteristics of lumbosacral evoked potentials in patients with established spinal cord injuryElectroencephalography and Clinical Neurophysiology/Evoked Potentials Section, Vol. 59, No. 2Ultrastructure of muscle spindle afferent terminations in lamina VI of the cat spinal cordBrain Research, Vol. 288, No. 1-2Parallel processing of somatosensory information: A theoryBrain Research Reviews, Vol. 6, No. 1Afferent projections from the rat longus capitis muscle studied by transganglionic transport of HRPAnatomy and Embryology, Vol. 166, No. 2The cytoarchitecture of gabaergic neurons in rat spinal cordBrain Research, Vol. 238, No. 2Axonal trajectory of single group Ia and Ib fibers in the cat spinal cordNeuroscience Letters, Vol. 8, No. 4Supplement to bibliography on muscle receptors: Their morphology, pathology, physiology, and pharmacologyExperimental Neurology, Vol. 55, No. 3Axonal projections of spinal interneurones excited by group I afferents in the cat, revealed by intracellular staining with horseradish peroxidaseBrain Research, Vol. 118, No. 1 More from this issue > Volume 37Issue 2March 1974Pages 282-93 https://doi.org/10.1152/jn.1974.37.2.282PubMed4273643History Published online 1 March 1974 Published in print 1 March 1974 Metrics