The localization of the motoneurons supplying the hindlimb muscles of the mouse

1981 ◽  
Vol 293 (1069) ◽  
pp. 477-508 ◽  
Keyword(s):  
Muscle Mass ◽  
Intramuscular Injection ◽  
Hindlimb Muscles ◽  
Lateral Motor Column ◽  
Spinal Segments ◽  
Muscle Nerve ◽  
Absolute Correlation ◽  
Deep Flexors ◽  
L1 And L2 ◽  
Ventral Muscle

The method of retrograde axonal transport of horseradish peroxidase (HRP) has been used to localize the motoneurons that innervate the mouse hindlimb musculature. Motoneurons were labelled following either intramuscular injection of an HRP solution or application of HRP to the cut end of a muscle nerve. When intramuscular injection was used the nerves to adjacent muscles were cut and deflected from the injection site to prevent motoneurons projecting to these muscles being labelled with HRP. For some muscles this procedure was inadequate since the nerves to adjacent muscles were too short to enable adequate deflexion. The motoneurons projecting to these muscles were labelled by the method of cut nerve exposure. The motoneurons that project to a single muscle or a group of muscles were organized as longitudinal columns. The positions of such motonuclei within the lateral motor column were similar in different animals for any given muscle or muscle group. Motoneurons innervating the anterior and medial femoral muscles were located in spinal segments L1 and L2. Motoneurons innervating the remaining hindlimb muscles were found in segments L3-L5. Topographic relationships between muscle motonuclei were in general found to be similar to those described for the cat. The principal differences to be noted between the two species were that the adductors motonucleus did not overlap with the hamstrings motonucleus in the mouse. Also the motonuclei supplying the deep flexors of the crural musculature and intrinsic musculature of the foot were located more ventrally relative to the posterior crural motonucleus in the mouse as compared to the cat. Consideration of muscle homologies between vertebrate classes enabled comparisons of the localization of motonuclei between the mouse and the other species studied. It was found that topographical relations between motonuclei were similar in all the species so far studied. There was no absolute correlation between the rostrocaudal position of a motonucleus and the position in the hindlimb of the muscle that it innervated. In general, motonuclei innervating muscles derived from the dorsal muscle mass were located lateral to motonuclei innervating muscles derived from the ventral muscle mass. Furthermore, within each muscle mass there is a relationship between rostrocaudal position of a motonucleus and the anteroposterior position of the muscle it supplies. Thus there is a relation between position of a motonucleus within the spinal cord and the derivation from the embryonic muscle mass of the muscle that it supplies.

Pathway selection by chick lumbosacral motoneurons during normal development

1981 ◽  
Vol 214 (1194) ◽  
pp. 1-18 ◽  
Keyword(s):  
Cell Death ◽  
Early Stage ◽  
Spinal Nerves ◽  
Functional Connections ◽  
Hindlimb Muscles ◽  
Lateral Motor Column ◽  
Normal Period ◽  
Axon Retraction ◽  
Muscle Nerve ◽  
Specific Muscle

Pathways taken by motoneuron axons from the lumbosacral lateral motor column to individual hindlimb muscles have been characterized throughout the normal period of outgrowth and the establishment of specific functional connections in the chick embryo. Axon pathways from individual cord segments were identified after injections of horseradish peroxidase (HRP) directly into the cord. Labelled motoneuron axons were then traced through the plexus and major nerve trunks to termi­nation sites within the limb. At stages 23-24 labelled axons within spinal nerves have just reached the base of the limb and have begun to converge and form the crural and the ischiadic plexus. Even at this early stage, before periods of muscle cleavage, motoneuron cell death and muscle nerve formation, axons show no evidence of widespread random distribution within the limb. Rather, they generally maintain their anterior-posterior position as far as the base of the limb. At stages 27-30, although axons to individual muscles were found to course in discrete tracts within the plexus and nerve trunks they also changed their topographical position with respect to other axons. Axon pathways to single muscles were characterized by tracing retrogradely labelled axons back to the cord after injections of HRP into specific muscle nerves. Axons destined for a single muscle are intermingled with other axons in the spinal nerves and proximal plexus but by the distal plexus have converged to form a discrete tract which then diverges as an individual muscle nerve at more distal levels. These observations exclude models for the establishment of specific connections in which there is widespread testing of the environment with removal of projection errors by cell death and/or axon retraction. They also exclude models that require axons to maintain their topographical position with respect to each other throughout their course.

The musculature and nervous system of the plerocercoid larva of Dibothriorhynchus grossum (Rud.)

Parasitology ◽  
1941 ◽  
Vol 33 (4) ◽  
pp. 373-389 ◽  
Author(s):  
Gwendolen Rees
Keyword(s):  
Nervous System ◽  
Muscle Mass ◽  
Nerve Cells ◽  
The Body ◽  
Lateral Nerve ◽  
Posterior Median ◽  
The Brain ◽  
Ventral Muscle ◽  
Nerve Cords ◽  
Extrinsic Muscles

1. The structure of the proboscides of the larva of Dibothriorhynchus grossum (Rud.) is described. Each proboscis is provided with four sets of extrinsic muscles, and there is an anterior dorso-ventral muscle mass connected to all four proboscides.2. The musculature of the body and scolex is described.3. The nervous system consists of a brain, two lateral nerve cords, two outer and inner anterior nerves on each side, twenty-five pairs of bothridial nerves to each bothridium, four longitudinal bothridial nerves connecting these latter before their entry into the bothridia, four proboscis nerves arising from the brain, and a series of lateral nerves supplying the lateral regions of the body.4. The so-called ganglia contain no nerve cells, these are present only in the posterior median commissure which is therefore the nerve centre.

Muscle growth, cell number, type and morphometry in single and twin fetal lambs during mid to late gestation

2000 ◽  
Vol 12 (6) ◽  
pp. 319 ◽  
Author(s):  
S. A. McCoard ◽  
W. C. McNabb ◽  
S. W. Peterson ◽  
S. N. McCutcheon ◽  
P. M. Harris
Keyword(s):  
Muscle Mass ◽  
Litter Size ◽  
Muscle Growth ◽  
Cell Number ◽  
Late Gestation ◽  
Postnatal Life ◽  
Cross Sectional ◽  
Hindlimb Muscles ◽  
Full Complement ◽  
Gastrocnemius Muscles

Muscle growth, myofibre number, type and morphometry were studied in large hindlimb muscles of single and twin fetal lambs during mid to late gestation. Placental insufficiency, evident by lower total placentome weight and number per fetus, resulted in reduced fetal weights from 100 to 140 days gestation in twins compared with singletons (at 140 days: 5016 108 g v. 5750 246 g, respectively; P<0.05). However, competition between littermates did not consistently reduce muscle mass (15–22%) until 140 days gestation. Apparent myofibre number increased with age, indicating that the full complement of myofibres in some large hindlimb muscles may be achieved during early postnatal life. Litter size did not impact on apparent myofibre number in the semitendinosus, plantaris or gastrocnemius muscles. However, a transient effect on myofibre number in the adductor femoris muscle was observed from 80–120 days gestation. The phenotypic maturation of myofibres was unaffected by increasing litter size. Smaller muscle mass in twins was associated with smaller myofibre cross-sectional area in the semitendinosus, adductor femoris and gastrocnemius muscles at 140 days gestation. A similar trend was observed for the plantaris muscle. These results indicate that while competition between littermates for nutrients in late gestation can impact on both fetal and muscle mass, the fetus has the capacity to buffer against the effects of restricted nutrient supply on myofibre hyperplasia and phenotypic maturation, but myofibre hypertrophy is compromised.

Metabolic responses to head-down suspension in hypophysectomized rats

1993 ◽  
Vol 75 (6) ◽  
pp. 2718-2726 ◽  
Author(s):  
C. R. Woodman ◽  
C. M. Tipton ◽  
J. Evans ◽  
J. K. Linderman ◽  
K. Gosselink ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Time Course ◽  
Citrate Synthase ◽  
O2 Consumption ◽  
Hindlimb Muscles ◽  
Impaired Ability ◽  
Norepinephrine Concentration ◽  
Hindlimb Muscle ◽  
Before And After ◽  
Hypophysectomized Rats

Rats exposed to head-down suspension (HDS) exhibit reductions in maximal O2 consumption (VO2max) and atrophy of select hindlimb muscles. This study tested the hypothesis that an endocrine-deficient rat exposed to HDS would not exhibit reductions in VO2max or hindlimb muscle mass. Hypophysectomized (HYPX) and sham-operated (SHAM) rats were tested for VO2max before and after 28 days of HDS or cage control (CC) conditions. No significant reductions in VO2max were observed in HYPX rats. In contrast, SHAM-HDS rats exhibited a significant reduction in absolute (-16%) and relative (-29%) measures of aerobic capacity. Time course experiments revealed a reduction in VO2max in SHAM-HDS rats within 7 days, suggesting that cardiovascular adjustments to HDS occurred in the 1st wk. HDS was associated with atrophy of the soleus (-42%) in SHAM rats, whereas HYPX rats exhibited atrophy of the soleus (-36%) and plantaris (-13%). SHAM-HDS rats had significantly lower (-38%) soleus citrate synthase activities per gram muscle mass than SHAM-CC, but no significant differences existed between HYPX-HDS and -CC rats. HDS rats had an impaired ability to thermoregulate, as indicated by significantly greater temperature increases per unit run time, compared with their CC counterparts. Pretreatment plasma epinephrine levels were significantly lower in HYPX than in SHAM rats. Norepinephrine concentration was similar for all groups except HYPX-HDS, in which it was significantly higher. HDS had no significant effect on thyroxine or triiodothyronine. SHAM-HDS rats had significantly lower concentrations of testosterone and growth hormone.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Fine-mapping of muscle weight QTL in LG/J and SM/J intercrosses

2010 ◽  
Vol 42A (1) ◽  
pp. 33-38 ◽  
Author(s):  
A. Lionikas ◽  
R. Cheng ◽  
J. E. Lim ◽  
A. A. Palmer ◽  
D. A. Blizard
Keyword(s):  
Body Weight ◽  
Muscle Mass ◽  
The Body ◽  
Mouse Strains ◽  
Muscle Weight ◽  
Hindlimb Muscles ◽  
Measured Weight ◽  
Genome Wide ◽  
A Genome ◽  
Underlying Mechanisms

Genetic variation plays a substantial role in variation in strength, but the underlying mechanisms remain poorly understood. The objective of the present study was to examine the mechanisms underlying variation in muscle mass, a predictor of strength, between LG/J and SM/J strains, which are the inbred progeny of mice selected, respectively, for high and low body weight. We measured weight of five hindlimb muscles in LG/J and SM/J males and females, in F1 and F2 intercrosses, and in an advanced intercross (AI), F34, between the two. F2 mice were genotyped using 162 SNPs throughout the genome; F34 mice were genotyped at 3,015 SNPs. A twofold difference in muscle mass between the LG/J and SM/J mouse strains was observed. Integrated genome-wide association analysis in the combined population of F2 and AI identified 22 quantitative trait loci (QTL; genome-wide P < 0.05) affecting muscle weight on Chr 2 (2 QTL), 4, 5, 6 (7 QTL), 7 (4 QTL), 8 (4 QTL), and 11 (3 QTL). The LG/J allele conferred greater muscle weight in all cases. The 1.5-LOD QTL support intervals ranged between 0.3 and 13.4 Mb (median 3.7 Mb) restricting the list of candidates to between 5 and 97 genes. Selection for body weight segregated the alleles affecting skeletal muscle, the most abundant tissue in the body. Combination of analyses in an F2 and AI was an effective strategy to detect and refine the QTL in a genome-wide manner. The achieved resolution facilitates further elucidation of the underlying genetic mechanisms affecting muscle mass.

Targeted disruption of Hoxd-10 affects mouse hindlimb development

Development ◽  
1997 ◽  
Vol 124 (22) ◽  
pp. 4505-4514 ◽  
Author(s):  
E.M. Carpenter ◽  
J.M. Goddard ◽  
A.P. Davis ◽  
T.P. Nguyen ◽  
M.R. Capecchi
Keyword(s):  
Spinal Cord ◽  
Regional Identity ◽  
Nerve Fibers ◽  
Mutant Mice ◽  
Sesamoid Bone ◽  
Sacral Plexus ◽  
Targeted Disruption ◽  
Lateral Motor Column ◽  
Spinal Segments ◽  
Underlying Causes

Targeted disruption of the Hoxd-10 gene, a 5′ member of the mouse HoxD linkage group, produces mice with hindlimb-specific defects in gait and adduction. To determine the underlying causes of this locomotor defect, mutant mice were examined for skeletal, muscular and neural abnormalities. Mutant mice exhibit alterations in the vertebral column and in the bones of the hindlimb. Sacral vertebrae beginning at the level of S2 exhibit homeotic transformations to adopt the morphology of the next most anterior vertebra. In the hindlimb, there is an anterior shift in the position of the patella, an occasional production of an anterior sesamoid bone, and an outward rotation of the lower part of the leg, all of which contribute to the defects in locomotion. No major alterations in hindlimb musculature were observed, but defects in the nervous system were evident. There was a decrease in the number of spinal segments projecting nerve fibers through the sacral plexus to innervate the musculature of the hindlimb. Deletion of a hindlimb nerve was seen in some animals, and a shift was evident in the position of the lumbar lateral motor column. These observations suggest a role for the Hoxd-10 gene in establishing regional identity within the spinal cord and imply that patterning of the spinal cord may have intrinsic components and is not completely imposed by the surrounding mesoderm.

Evidence for axonal ‘decision regions’ in the axolotl peripheral nervous system

Development ◽  
1988 ◽  
Vol 102 (4) ◽  
pp. 823-836
Author(s):  
S. Wilson ◽  
N. Holder
Keyword(s):  
Nervous System ◽  
Peripheral Nervous System ◽  
Spatial Organization ◽  
Retrograde Transport ◽  
Branch Points ◽  
Spinal Nerves ◽  
Lateral Motor Column ◽  
Decision Region ◽  
Muscle Nerve ◽  
Axial Musculature

Horseradish peroxidase (HRP) was employed to analyse the spatial organization of axons within nerves of the axolotl peripheral nervous system. HRP applications to the lateral motor column, spinal nerves and muscle nerve branches were examined after orthograde or retrograde transport. Axons change relative positions at particular limb regions, notably at the limb plexi, but also at branch points at other limb levels. Such areas of axon reorganization (termed ‘decision regions’ in line with Tosney & Landmesser (1985) J. Neurosci. 5, 2345) are interspersed by lengths of nerve in which axons run parallel to one another. A decision region is also described which involves only axons destined for axial musculature. The detailed anatomy of axon groups is discussed in terms of the likely mechanisms responsible for its formation during development. We conclude that, despite considerable variation in nerve pattern not seen in higher vertebrates, neuromuscular specificity in the axolotl limb is established largely by local pathway cues guiding axons to their appropriate targets.

Intramuscular β2-agonist administration enhances early regeneration and functional repair in rat skeletal muscle after myotoxic injury

2008 ◽  
Vol 105 (1) ◽  
pp. 165-172 ◽  
Author(s):  
James G. Ryall ◽  
Jonathan D. Schertzer ◽  
Tammy M. Alabakis ◽  
Stefan M. Gehrig ◽  
David R. Plant ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Side Effects ◽  
Cardiac Hypertrophy ◽  
Muscle Mass ◽  
Intramuscular Injection ◽  
Therapeutic Potential ◽  
Cardiovascular Effects ◽  
Skeletal Muscle Regeneration ◽  
Cardiovascular Side Effects ◽  
The Right

Systemic administration of β2-adrenoceptor agonists (β2-agonists) can improve skeletal muscle regeneration after injury. However, therapeutic application of β2-agonists for muscle injury has been limited by detrimental cardiovascular side effects. Intramuscular administration may obviate some of these side effects. To test this hypothesis, the right extensor digitorum longus (EDL) muscle from rats was injected with bupivacaine hydrochloride to cause complete muscle fiber degeneration. Five days after injury, half of the injured muscles received an intramuscular injection of formoterol (100 μg). Muscle function was assessed at 7, 10, and 14 days after injury. A single intramuscular injection of formoterol increased muscle mass and force-producing capacity at day 7 by 17 and 91%, respectively, but this effect was transient because these values were not different from control levels at day 10. A second intramuscular injection of formoterol at day 7 prolonged the increase in muscle mass and force-producing capacity. Importantly, single or multiple intramuscular injections of formoterol did not elicit cardiac hypertrophy. To characterize any potential cardiovascular effects of intramuscular formoterol administration, we instrumented a separate group of rats with indwelling radio telemeters. Following an intramuscular injection of formoterol, heart rate increased by 18%, whereas systolic and diastolic blood pressure decreased by 31 and 44%, respectively. These results indicate that intramuscular injection can enhance functional muscle recovery after injury without causing cardiac hypertrophy. Therefore, if the transient cardiovascular effects associated with intramuscular formoterol administration can be minimized, this form of treatment may have significant therapeutic potential for muscle-wasting conditions.

scholarly journals The magnitude of the exercise pressor reflex is influenced by the active skeletal muscle mass in the decerebrate rat

2020 ◽  
Vol 318 (1) ◽  
pp. R30-R37
Author(s):  
Juan A. Estrada ◽  
Guillaume P. Ducrocq ◽  
Marc P. Kaufman
Keyword(s):  
Lactic Acid ◽  
Muscle Mass ◽  
Calcaneal Tendon ◽  
Thin Fiber ◽  
Exercise Pressor Reflex ◽  
Hindlimb Muscles ◽  
Pressor Responses ◽  
Decerebrate Rat ◽  
Pressor Reflex ◽  
Stimulation Of

The exercise pressor reflex is composed of two components, namely the muscle mechanoreflex and the muscle metaboreflex. The afferents evoking the two components are either thinly myelinated (group III) or unmyelinated (group IV); in combination they are termed “thin fiber afferents.” The exercise pressor reflex is often studied in unanesthetized, decerebrate rats. However, the relationship between the magnitude of this reflex and the number of thin fiber afferents stimulated by muscle contraction is unknown. This lack of knowledge prompted us to test the hypothesis that the magnitude of the exercise pressor reflex was directly proportional to the amount of muscle mass activated. Muscle mechanoreceptors were stimulated by stretching the calcaneal tendon. Likewise, muscle metaboreceptors were stimulated by injecting lactic acid into the arterial supply of the hindlimb muscles. In addition, both muscle mechanoreceptors and metaboreceptors were stimulated by statically contracting the hindlimb muscles. We found that simultaneous bilateral (both hindlimbs) stimulation of thin fiber afferents with stretch, lactic acid, and static contraction evoked significantly greater pressor responses than did unilateral (one hindlimb) stimulation of these afferents. In addition, the magnitude of the pressor responses to bilateral simultaneous stimulation of thin fiber afferents evoked by stretch, lactic acid, and contraction was not significantly different from the magnitude of the sum of the pressor responses evoked by unilateral stimulation of these afferents by stretch, lactic acid, and contraction. We conclude that the magnitude of the exercise pressor reflex and its two components is dependent on the number of afferents stimulated.

Transverse Myelitis from Intraarterial Penicillin

Neurosurgery ◽  
1984 ◽  
Vol 15 (4) ◽  
pp. 552-556 ◽  
Author(s):  
Wesley W. Stafford ◽  
Hernando Mena ◽  
Walter S. Piskun ◽  
Michael R. Weir
Keyword(s):  
Spinal Cord ◽  
Muscle Mass ◽  
Intramuscular Injection ◽  
Transverse Myelitis ◽  
Rapid Progression ◽  
Benzathine Penicillin ◽  
Thoracic Region ◽  
Intravascular Injection ◽  
Small Muscle ◽  
Standard Techniques

Abstract A child was given intramuscular benzathine penicillin and experienced manifestations of sudden, irreversible transection of the spinal cord in the lower thoracic region. The biopsy supported an intravascular injection with occlusion of the spinal vasculature as the etiological mechanism. A review of similar cases reveals a recurring pattern-intramuscular injection with standard techniques and sites into a small muscle mass without evident blood return followed by rapid progression of paralysis. The problem seems to turn upon an inability to recognize the inadvertent intraarterial injection.

Sign in / Sign up

Export Citation Format

Share Document