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At least 775 records · Page 43Linked to original sources
PubMed1999

Neuropeptides in insect sensory neurones: tachykinin-, FMRFamide- and allatotropin-related peptides in terminals of locust thoracic sensory afferents.

Sensory afferents in the thoracic ganglia of the locust Locusta migratoria were labelled with antisera to different neuropeptides: locustatachykinins, FMRFamide and allatotropin. The locustatachykinin-immunoreactive (LTKIR) sensory fibres were derived from the legs and entered the ventral sensory neuropil of each of the thoracic ganglia via nerve 5. In the thoracic neuropil, the LTKIR sensory fibres formed a distinct plexus of terminations ventrally in the ipsilateral hemisphere. The peripheral cell bodies of the sensory neurones could not be revealed, but lesion experiments indicated that origin of the LTKIR fibres was the tarsus of each leg. Possibly the thin fibres are from tarsal chemoreceptors. Double labelling immunocytochemistry revealed that all the LTKIR sensory fibres contained colocalized FMRFamide immunoreactivity. A larger population of sensory fibres reacted with antiserum to moth (Manduca sexta) allatotropin. By means of double labelling immunocytochemistry, we could show that the LTKIR fibres constituted a subpopulation of the larger set of allatotropin-like immunoreactive fibres. Thus some sensory fibres may contain colocalized peptides related to locustatachykinins, FMRFamide-related peptide(s) and allatotropin-like peptide. A separate non-overlapping small set of sensory fibres in nerve 5 reacted with an antiserum to serotonin. Sensory fibres of the other nerves of the ventral nerve cord, including the abdominal ganglia, did not react with the peptide antisera. Since acetylcholine is the likely primary neurotransmitter of insect sensory fibres, it is possible that the peptides and serotonin are colocalized with this transmitter and serve modulatory functions in a subset of the leg afferents.

Amputation, Surgical↗
PubMed1990

Vascular changes in the chest wall after unilateral resection of the intercostal nerves in the growing rabbit.

In young, growing white New Zealand rabbits the third, fourth, and fifth intercostal nerves were resected anteriorly on the right side. Six months later the animals developed structural left convex scoliosis, with a Cobb angle ranging from 15 to 31 degrees. The vascular structure changes of the anterior chest wall were evaluated by measuring surface temperature and fluorescein intensity of the pectoral muscles, and the capillary density of the pectoral and intercostal muscle and periosteal parts of the ribs after angiography. In five normal control rabbits there was neither scoliotic deformity nor significant differences in the examined vascular variables between the right and left sides. In the animals undergoing resection, the temperature of the pectoral muscle on the side of the denervation--the right side--was significantly increased (p less than 0.05), but the difference was not correlated to the degree of scoliosis. The fluorescence index was significantly greater (p less than 0.05) on the right than on the left side, this difference being fairly strongly correlated to the degree of scoliosis. The capillary densities of the costal periosteum and the intercostal and the pectoral muscle were significantly greater (p less than 0.05) on the right than on the left side, and the difference was positively correlated to the degree of scoliosis. The volume density of the periosteum of the ribs was likewise significantly greater on the right. These results demonstrate that unilateral resection of the intercostal nerves significantly increases the vascularity of the structures on the denervated side of the thorax.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1979

Regional differences in the timing of synapse elimination in skeletal muscles of the neonatal rabbit.

The time course of disappearance of polyneuronal innervation during development was studied electrophysiologically in skeletal muscles of the rabbit. There were differences of up to a week in the estimated time of onset of synapse elimination in various muscles, with a tendency for the process to begin earlier in muscles situated more anteriorly in the body. There were also differences among muscles in the peak rate of synapse loss during maturation, but these differences do not appear to be related to position in the body or to contractile properties of the muscle.

Aging↗
PubMed1975

Central and peripheral neural respiratory activity in the mature sheep foetus and newborn lamb.

Activity from respiratory neurones in the medulla, the phrenic and intercostal nerves was recorded in 25 foetal sheep, exteriorized a few days before term from ewes given a spinal anaesthetic, and from nine newborn lambs, anaesthetized with an allobarbitone-urethane mixture. In 12 foetuses, there was little or no sustained respiratory activity, central activity consisting of tonically discharging expiratory and other neurones and silent inspiratory neurones. In the remaining 13 foetuses, respiratory activity was periodic or continuous and it was possible to confirm that the motor component of the respiratory reflex was mature, that apnoea was not due to medullary depression, that foetal respiration was unaffected by chemoreceptor stimulation, by noise, by light, by electrical stimulation of the sciatic nerve and only slightly by inflation or deflation of the lungs. All these stimuli were effective shortly after birth. Occlusion of the umbilical cord caused poorly sustained gasps in the "non-breathing" foetuses and in the "breathing" foetuses, abolition of inspiratory and expiratory activity in the medulla and the onset of gasps and flattening of the electro-corticogram. Rhythmic respiration resumed after release of the cord with a latency which varied with the duration and severity of the asphyxia. This type of respiratory depression was not reflex but due to a direct, central action of hypoxia. The sequence of respiratory events at birth is discussed.

Animals↗
PubMed1985

Reflex responses evoked in the adrenal sympathetic nerve to electrical stimulation of somatic afferent nerves in the rat.

The present study was initiated to determine the role of somatic A (myelinated) and C (unmyelinated) afferent fibers in both responses of increases and decreases in adrenal sympathetic nerve activities during repetitive mechanical pinching and brushing stimulations of the skin in anesthetized rats with central nervous system (CNS) intact. Accordingly, changes in adrenal sympathetic nerve activity resulting from repetitive and single shock electrical stimulation of various spinal afferent nerves, especially the 13th thoracic (Th13) spinal nerve and the sural nerve, were examined in urethane/chloralose-anesthetized rats. Repetitive electrical stimulation of A afferent fibers in Th13 spinal or sural nerve decreased the adrenal nerve activity similarly as brushing stimulation of skin of the lower chest or hindlimb did, while repetitive stimulation of A plus C afferent fibers of those nerves increased the adrenal nerve activity as pinching stimulation of those skins did. Single shock stimulation of spinal afferent nerves evoked various reflex components in the adrenal nerve: an initial depression of spontaneous activity (the early depression); the following reflex discharge due to activation of A afferent fibers (the A-reflex); a subsequent reflex discharge due to activation of C afferent fibers (the C-reflex); and following post-excitatory depressions. These reflexes seem to be mediated mainly via supraspinal pathways since they were abolished by spinal transection at the C1-2 level. Although the supraspinal A- and C-reflexes could be elicited from stimulation of a wide variety of spinal segmental afferent levels, the early depression was more prominent when afferents at spinal segments closer to the level of adrenal nerve outflow were excited. It is suggested that the decreased responses of the adrenal nerve during repetitive electrical stimulation of A afferent nerve fibers are attributable to summation of both the early depression and post-excitatory depression evoked by single shock stimulation, while the increased responses during repetitive stimulation of A plus C afferent fibers are attributable to summation of the C-reflex after single shock stimulation. In spinalized rats, repetitive stimulation of Th13 always increased the adrenal nerve activities regardless of whether A fibers alone or A plus C fibers were stimulated, just as brushing and pinching of the lower chest skin always increased them. The increased responses in spinal animals seem to be related to the fact that single electrical stimuli of Th13 produced A- and C-reflexes of spinal origin without clear depressions.

Adrenal Glands↗
PubMed1989

Post-axillary dissection pain in breast cancer due to a lesion of the intercostobrachial nerve.

Seven patients with breast carcinoma and post-axillary dissection pain are described. They complained about pain in the axilla, inner side of the upper arm and/or shoulder. All had undergone a partial or radical breast amputation including an axillary lymph node dissection. On neurological examination all had evidence of a lesion of the intercostobrachial nerve. The pain was not associated with lymphedema and only one patient had undergone radiotherapy to the axillary and supraclavicular area. Post-axillary dissection pain is probably a more appropriate name than the usual post-mastectomy pain for this syndrome. During the dissection, the intercostobrachial nerve is often lesioned, which may give rise to neuropathic pain of that nerve.

Adult↗
PubMed1988

Neurotization of the remaining latissimus dorsi muscle following muscle flap transplant.

The neurotization of the remaining latissimus dorsi muscle at the donor site is a useful technique in children. It is performed during the same surgical procedure as the free vascularized flap and consists of a neurolysis of the thoracodorsal nerve into three to five fascicles, and introducing them into three to five different openings in the muscle fibers. This technique is important in young patients for avoiding functional long-term sequelae such as scoliosis and developmental muscular defects of the vertebral column. Three cases are reported, with evaluation by electromyography and biopsy.

Adolescent↗
PubMed1979

Outpatient breast surgery under intercostal block anesthesia.

During the past 3 years, we have performed various breast operations in 320 patients under local anesthesia, using intercostal nerve block. The amount of local anesthetic solution required has been about 20 ml 1% lidocaine for blocking both sides, and an additional 24 ml of 0.5% lidocaine during the surgery. This dosage is well within safe limits. We have found that various breast operations, ranging from augmentation mammaplasty to a staged reconstruction after mastectomy, can be done with this method of anesthesia. The complications attributable to the nerve block were nil in our series.

Ambulatory Care↗
PubMed1984

Respiratory failure following intercostal nerve blockade.

A case of respiratory failure following postoperative intercostal nerve blockade is described. A possible mechanism is postulated and the evidence in favour of intercostal blockade in patients with chronic airways disease is questioned. The need for caution when managing such patients with regional blockade is emphasised.

Aged↗
PubMed1980

Effects of intercostal nerve blocks on pulmonary mechanics in healthy men.

Bilateral block of the 5th through the 11th intercostal nerves was induced in 16 healthy men. In eight of the men, bupivacaine 0.25% was used and in the other eight, etidocaine 0.5%. Before and after induction of the block flow/volume curves, maximal airway pressures, and pulmonary compliance, were recorded, and helium spirometry and multiple and single breath nitrogen wash-outs were performed. There were no differences between the results in the two groups, and the material was therefore pooled. Total lung capacity was decreased by 4%. There was no increase in residual volume, though the maximal expiratory airway pressure decreased by 7%. There was an 8% decrease in functional residual capacity. Pulmonary recoil appeared to be unchanged, as also did the effort-independent peak expiratory flow rates. According to the pulmonary nitrogen clearance index, the overall pulmonary time constant did not alter, while the slope of the alveolar plateau in the single breath nitrogen wash-out test increased by 9%. The significance of the latter finding is unclear, but it is concluded that the nerve block had no obvious effects on pulmonary mechanics, the changes observed rather being attributable to effects on the chest wall.

Adult↗
PubMed1978

Interaction of descending spinal sympathetic pathways and afferent nerves.

With the use of computer-aided techniques, the interaction of descending spinal sympathetic pathways and afferent nerve fibers (cervical dorsal roots and tibial nerve) in regulation of thoracic (T2) preganglionic nerve activity was investigated in anesthetized, vagotomized, and paralyzed cats. High-frequency activation of a sympathoinhibitory pathway (ventrolateral funiculus) depressed the evoked discharges in the T2 preganglionic nerve elicited by stimulation of a sympathoexcitatory pathway (dorsolateral funiculus) and the spinal component of the somatosympathetic reflex. Submaximal evoked responses were also inhibited through baroreceptor reflex activation (blood pressure elevations up to 225 mmHg). Facilitation of the spinal component of the somatosympathetic reflex occurred during stimulation of the excitatory pathway. Carotid occlusion (baroreceptor inactivation) facilitated the submaximal evoked discharges from stimulation of the descending excitatory pathway. These data support the contention that sympathetic nerve activity can be modified by the integration of excitatory and inhibitory impulses at the spinal level.

Afferent Pathways↗
PubMed1977

Neonatal chest wall afferents and regulation of respiration.

We have studied two groups of eight preterm infants, relating chest wall afferent information to respiratory timing. Rib cage and abdominal motion were monitored by magnetometers and flow and tidal volume via a face mask. In the first group, studies were done in REM sleep when spontaneously occurring distortion of the rib cage occurred and a significant linear relationship between the rate of distortion of the chest wall and shortening of the inspiratory time (Ti) was found in all infants. Reduction in this distortion by the use of continuous positive airway pressure (CPAP) or continuous negative pressure at the body surface (CNeg) was associated with a significant (P less than 0.01) lengthening of Ti. Absence of changes in Ti when pressure was applied in quiet sleep suggested that lung volume or chemical changes were not involved. In the second group of infants we artificially generated the afferent inflow by using vibratory stimuli applied in one intercostal interspace and produced a significant (P less than 0.05) shortening in Ti. We suggest that the distortion of the rib cage in REM sleep generates afferent information from intercostal muscle spindles that is related to the rate of distortion and this, via a supraspinal reflex, inhibits phrenic motoneuron discharge. It may then be of importance in the etiology of apneic episodes in these infants. Applied pressure may be of benefit because it reduces an inhibitory afferent inflow.

Afferent Pathways↗
PubMed1989

Mechanical arrangement of the parasternal intercostals in the different interspaces.

When the parasternal intercostal in a single interspace is selectively denervated in dogs with diaphragmatic paralysis, it continues to shorten during both quiet and occluded inspiration. In the present studies, we have tested the hypothesis that this passive parasternal inspiratory shortening is due to the action of the other parasternal intercostals. Changes in length of the denervated third right parasternal were measured in eight supine phrenicotomized animals. We found that 1) the inspiratory muscle shortening increased after denervation of the third left parasternal but gradually decreased with denervation of the parasternals situated in the second, fourth, and fifth interspaces; 2) the muscle, however, always continued to shorten during inspiration, even after denervation of all the parasternals; 3) stimulating selectively the third left parasternal caused a muscle lengthening; and 4) bilateral stimulation of the parasternals in the second or the fourth interspace produced a muscle shortening. We conclude that 1) the two parasternals situated in the same interspace on both sides of the sternum are mechanically arranged in series, whereas the parasternals located in adjacent interspaces are mechanically arranged in parallel; and 2) if a denervated parasternal continues to shorten during inspiration, this is in part because of the action of the parasternals in the adjacent interspaces and in part because of other inspiratory muscles of the rib cage, possibly the external intercostals and the levator costae.

Animals↗