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PubMed1975

The cardioregulatory system of crayfish: neuroanatomy and physiology.

1. The anatomical arrangement of the cardioregulatory nerves and their physiological activity during cardiac modulation were analysed in Procambarus clarkii. 2. The bilaterally arranged pairs of cardioinhibitors and cardioaccelerator axons, in nerves SN II and SN III respectively, were physiologically identified by correlating spikes in SN II and SN III with the same spikes in the dorsal nerve, which innervates the heart. 3. The cardioinhibitor neurone fired tonically in varied sporadic bursts. During periods of cardiac inhibition, however, this neurone discharged in a long chain of spikes at a characteristic frequency of 40-50Hz. 4. The cardioaccelerator neurone fired tonically at 2-3 Hz but on occasion its activity reached 12 Hz. 5. Three inhibitory cardiac reflexes were analysed. The sensory modalities for the reflexes included (a) stretch of the dorsal pericardial wall, (b) chemical stimulation of coxal hair sensilla with glucose and (c) tactile stimulation of hair sensilla in and below the gill chamber, on the antennae, the antennules and on the anterior cephalothorax. 6. The discharge of both cardioinhibitor neurones showed a weak temporal correlation suggesting a common presynaptic drive, while the pair of cardioaccelerators appeared to have a reciprocal relationship with the cardioinhibitors.

Animals↗
PubMed1980

Cardiac, aortic, pericardial, and pulmonary receptors in the dog.

Afferent nerve activity from left and right atrial, left and right ventricular, interventricular septal, papillary muscle, pericardial, aortic and pulmonary vascular receptors was recorded from the left T3 white ramus communicans and the innominate, dorsal, recurrent, ventromedial, craniovagal and caudovagal cardiac nerves in alpha-chloralose-anesthetized dogs. The receptors were localized and the nature of the stimuli required to excite these receptors was also determined. Some ventricular receptors were excited during maximal contraction of the myocardium. Other ventricular and aortic receptors were stimulated by elevation of intracardiac or aortic pressure. The pericardial, atrial, and papillary muscle receptors were excited by stretching the surrounding tissue. The discharge patterns of these receptors were not always synchronous with the events of the cardiac cycle. The stimuli required to excite each type of receptor (ventricular, atrial, etc.) and their resultant discharge patterns were not identical for all of the receptors. Excitation of cardiac receptors with sympathetic afferents resulted in 1--2 spikes per cardiac cycle, whereas receptors with vagal afferents resulted in bursts of spikes per cardiac cycle.

Action Potentials↗
PubMed1976

The pectoral anatomy of selected Ostariophysi. I. The Characiniformes.

The muscles and bones of the pectoral fin of Serrasalmus nattereri, the piranha, resemble those of generalized, lower teleosts with specializations related to a body shape adapted for high-speed carnivory; the pectoral fins being highly mobile with strong ligaments to the rays. The presence of two occipital nerves appears primitive, while the emergence of the subclavian artery within the branchial cavity, as in Gasteropelecus sternicla, appears specialized. The muscles and bones of the latter fish, a fresh-water flying fish, are specialized for self-propelled, aerial flight in the fusion of the right and left girdles greatly expanded for insertions of complex appendicular (flight) muscles, and in the consolidation of the rays and radials into one functional unit moving vertically in flight through contraction of vertical, massive ventral flight muscles. The bony pectoral anatomy of Electrophorus electricus, the electric eel, is specialized in having a mobile joint between the primary girdle and the cleithrum, the former being suspended vertically from the cleithrum by ligaments. The proximal radials and rays are very numerous and vertically aligned. The cleithrum is shaped to accommodate the extensive sternohyoid and pharyngocleithral muscles. The sheet-like appendicular muscles extend beyond the special joint and control its movement. The deeper muscles do not cross this joint. The arterial system is specialized in lacking a deep brachial artery.

Animals↗
PubMed2005

Pectoral nerve conduction studies: technique in healthy subjects and evaluation of brachial plexopathy.

OBJECTIVE: To define the optimal nerve conduction study (NCS) technique of the pectoral nerves and evaluate its clinical utility. DESIGN: Prospective electrophysiologic study with healthy controls. SETTING: Electrophysiologic laboratory in a large general hospital. PARTICIPANTS: Thirty healthy controls and 10 patients with cervical root or brachial plexus pathologies. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Correlation of pectoral NCS with electromyography and magnetic resonance imaging. RESULTS: For pectoral NCS, the mean values +/- standard deviation of onset latency, amplitude, and interside amplitude ratio (ratio of smaller over larger amplitude) were 2.01+/-0.22 ms, 11.75+/-2.21 mV, and .95+/-.04 mV, respectively. Subject age correlated significantly with both onset latency (r=.46, P<.001) and amplitude (r=-.34, P<.008). All 5 patients with brachial plexopathy had amplitude ratios below the normal limit of controls (.87). However, this was not seen for all 5 patients with cervical spondylotic radiculopathy. CONCLUSIONS: The pectoral NCS technique is feasible in healthy subjects. It is useful when differentiating brachial plexopathy from cervical root lesions.

Adult↗
PubMed2002

Dose-related attenuation of cardiac sympathetic nerve activity and intracardiac conduction with thoracic epidural clonidine in alpha-chloralose-anesthetized cats.

Epidural clonidine produces hypotension, bradycardia and sympatholysis. We studied the dose-effects of thoracic epidural and intravenous clonidine (1 to 8 microg/kg) on cardiac sympathetic nerve activity (CSNA), hemodynamics and intracardiac conduction in cats anesthetized with alpha-chloralose. Mean arterial pressure was decreased with epidural clonidine doses above 2 microg/kg, and to a greater extent with 4 microg/kg than 8 microg/kg. Sinus heart rate, Wenckebach atrial rate and CSNA were significantly decreased and corrected sinus node recovery time and Atrium-His interval were significantly prolonged with doses above 2 microg/kg. Vagotomy induced no significant change in these parameters. Thoracic epidural clonidine doses above 2 microg/kg caused a similar extent of sympatholysis. Less of CSNA decrease and hemodynamic changes by intravenous clonidine suggested that sympatholysis caused by epidural clonidine was primarily mediated by spinal mechanism, although hemodynamic changes were influenced by clonidine systemically redistributed from epidural space. Vagal facilitation played no role in suppression of the sinoatrial and AV nodal functions.

Anesthesia↗
PubMedDate not supplied

Hemodynamic response to in situ latissimus dorsi muscle stimulation: implications in dynamic cardiomyoplasty.

Dynamic cardiomyoplasty (DCM) involves the electrical stimulation of a pedicled latissimus dorsi muscle flap wrapped around the falling ventricle as a means of cardiac assist. To further elucidate a potential neurohumoral mechanism for improvement of cardiac output after myoplasty, we evaluated the hemodynamic effects of in situ stimulation of the latissimus dorsi muscle (in the absence of cardiomyoplasty). In seven mongrel dogs, a nerve cuff electrode (Medtronic 6901) was placed around the left thoracodorsal nerve (TDN). This was attached to a pulse generator (Medtronic, Itrel 7420), delivering a 4.0 volt, 0.19 second on, 0.81 second off, 33 Hz, 210 microsecond pulse width, cyclic bursts similar to that used in DCM. Stroke volume index (SVI) and other hemodynamic parameters as well as plasma norepinephrine (NE) levels were measured at five stages: baseline, stimulator on at 0, 2, and 5 minutes, and stimulator off at 30 minutes after. The animals were then subjected to 4 weeks of rapid pacing at 240 beats/min (Medtronic 8329) to induce heart failure, and as the rapid pacing was discontinued, measurements were repeated as above. After rapid pacing, cardiac function was significantly depressed, and NE was elevated (133 +/- 69 versus 500 +/- 353 pg/mL, p < 0.05). In the normal hearts, TDN stimulation increased SVI, heart rate, systemic pressure, and NE levels. In heart failure, however, no significant changes in cardiac function and NE levels were noted. In conclusion, our data indicate that in the normal hearts, afferent impulses from TDN stimulation alone may augment cardiac function by means of a neurohumoral effect that is not seen in severe heart failure. The implications of these findings in DCM are discussed.

Animals↗
PubMed2006

The surgical anatomy of the ansa pectoralis.

Detailed anatomical knowledge of the pectoral nerves is of clinical importance in surgeries as diverse as limb neurotization, mastectomy, orthopedic procedures and operations related to trauma. The brachial plexus of 200 cadavers were examined in an attempt to clarify the normal origins, courses and variations of the nerves with special emphasis on the ansa pectoralis (AP). In 75% the MPN arose from the anterior division of the inferior trunk of the brachial plexus and in 25% it arose from the medial cord. In 40% of specimens, the LPN arose from a single contributing nerve (anterior division of the superior trunk, 11%; anterior division of the middle trunk 18%; lateral cord, 11%). In the remaining 60% of specimens, the LPN arose from the fusion of two rootlets derived variably from the anterior divisions of the superior and middle trunks and the lateral cord. A single AP was found to be present bilaterally in 200 (100%) of the specimens. Classification of the AP was based upon its origin from the upper or lower rootlet of the LPN, the LPN itself, or from the deep branch of the LPN. AP-1 (42%) arose from the deep branch of the LPN; AP-2 (28%) arose directly from the LPN; AP-3 (25%), arose from the lower rootlets of the LPN and rarely, the AP arose from the upper rootlet of the LPN and crossed posterior to the lower rootlet to communicate with the MPN (AP-4, 5%). Irrespective of the aforementioned types, the AP was found to be present, crossing the second segment of the axillary artery in 90% of the specimens. These results could prove useful during the preoperative planning of neurotization and other surgical procedures involving the axilla.

Aged↗
PubMed2000

Sonographic measurement of needle insertion depth in paravertebral blocks in women.

Single-injection paravertebral block offers adequate unilateral analgesia for thoracic and upper abdominal surgery. This technique is easy to learn but there is a risk, albeit low, of pleural puncture. The aim of the study was to determine whether sonographic measurements of the distances from the skin to the transverse process and to the parietal pleura are useful for calculating the required depth of needle insertion. Before puncture of the paravertebral space, the distances from the skin to the transverse process and to the parietal pleura were measured by sonography. The deviation of the needle from the horizontal plane was measured and an angle correction for the insertion depth was calculated. Twenty-two women undergoing elective unilateral breast surgery were studied. Sonographic visualization of the transverse process and the parietal pleura and measurement of their distances from the skin was successful in all women. Puncture of the paravertebral space failed in one obese woman. There was a very close correlation between needle insertion depth from the skin to the transverse process and the distance measured by ultrasound if angle correction was used (adjusted r2=0.95). Similarly, there was excellent correlation between the angle-corrected ultrasound distance from the skin to the parietal pleura and the distance from the skin to the paravertebral space (adjusted r2=0.92).

Aged↗
PubMed2000

Neuropathology of bouncer Long Evans, a novel dysmyelinated rat.

BACKGROUND AND PURPOSE: Spontaneous animal mutants affected by abnormal formation of myelin in the central nervous system (CNS) are useful in studies on myelinogenesis and remyelination leading to better understanding of cellular and molecular interactions involved in myelin repair. A novel rat mutant, Bouncer Long Evans (LE-bo) is severely dysmyelinated, but with exceptional longevity, and its clinical and pathologic phenotype are described. METHODS: Clinical observations, genetic studies, and determination of longevity were performed in a colony of rats, including carriers of LE-bo phenotype producing the mutant animals. Comprehensive histologic studies were performed on all perfusion-fixed tissues, and ultrastructural examination of the optic nerve and thoracic part of the spinal cord also was done in rats 1 to 14 weeks old. RESULTS: The LE-bo phenotype is characterized by whole body tremor, progressively severe ataxia, and severe seizure activity. The LE-bo phenotype is transferred as an autosomal recessive trait and is stable. The LE-bo rat can survive in good health beyond 45 weeks. Neuropathologic changes include severe global dysmyelination, with thin uncompacted myelin sheaths in young rats forming no major dense line, whereas the myelin sheaths of the peripheral nervous system appear normal. Oligodendrocytes degenerate with apparently progressing accumulation of membranous material in the perikaryon. Large numbers of immature glial cells were detected in the CNS of LE-bo rats at 4 to 14 weeks. CONCLUSION: The LE-bo rat is severely dysmyelinated due to inability of its oligodendrocytes to form myelin sheaths. Similarities of the LE-bo rat and Long Evans Shaker (les) rat neuropathologic features, such as severe dysmyelination, lack of major dense line in uncompacted myelin sheaths, apparent proliferation of oligodendroglial cells, and considerable longevity, are striking and suggest that a LE-bo mutation may functionally affect the myelin basic protein gene.

Animals↗
PubMed1993

Chronic stimulation enhances extramyocardial collateral blood flow after a cardiomyoplasty.

We have previously demonstrated that collateral blood flow can be established between skeletal muscle and myocardium in animals that have undergone a latissimus dorsi cardiomyoplasty. We have also shown that 5 minutes after the thoracodorsal nerve is electrically stimulated at 1.25 Hz, there is a sixfold increase in the collateral blood flow between the latissimus dorsi and the heart. In this experiment, we hypothesized that chronic stimulation of a latissimus dorsi cardiomyoplasty would result in a sustained increase in the latissimus-derived collateral blood flow. In 24 adult male goats, an ameroid constrictor was placed around a branch of the circumflex coronary artery, and a latissimus dorsi cardiomyoplasty was performed. After a rest period of about 1 week, the latissimus dorsi cardiomyoplasties were stimulated continuously at a 2-Hz frequency for 6 weeks. Collateral blood flow between the muscle and the heart was then measured with colored microspheres. Sixteen animals survived to the final experiment, and collaterals developed in 10. In these 10 animals, the latissimus collaterals continuously delivered 0.17 +/- 0.03 mL.g-1 x min-1 (mean +/- the standard error) of blood to ischemic myocardium. This flow represents 24.0% +/- 3.9% of the flow measured to normal myocardium. These results demonstrate that in an animal model of coronary artery disease, chronic electrical stimulation of a latissimus dorsi cardiomyoplasty maintains an elevated level of latissimus-derived collateral blood flow to the myocardium.

Animals↗
PubMed1991

[The muscular arch of the axilla and its nerve supply in Japanese adults].

We examined 94 axillary regions of 47 Japanese adults and found the muscular arch of the axilla (Maa) in five sides of three cadavers as well as the tendinous arch of the axilla (Taa) in two sides of two cadavers. The results are summarized as follows: 1) The frequency of Maa was 6.4% of the total bodies and 5.3% of the sides in this series. 2) In the left side of a 57-year-old male (No. 427), Maa was attached to the surface of the coracobrachialis muscle after fusing with the dorsal surface of the inserting tendon of the pectoralis quartus muscle. Both muscles were supplied by the caudal pectoral nerve (Npc) from the medial pectoral nerve. Moreover, in this same specimen, the sternalis muscle was recognized on the ventral surface of the pectoralis major muscle. In the left side of a 93-year-old female (No. 386), the cranial part of the muscular arch of the axilla (Cpa) was extended to the coracoid process by a tendon and attached to the abdominal part of the pectoralis major by two muscle bundles supplied by independent branches from Npc. One muscle bundle was attached to the lower margin of the abdominal part of the pectoralis major on the same plane, and the other bundle was located on the dorsal surface of the abdominal part. In a 74-year-old female (No. 411), the well-developed lateral part of the muscular arch of the axilla (Lpa) was attached to the inferior side of the tendinous arch. According to Ruge (1914) and Kasai et al. (1977), this arch was in the transition of the muscle bundle of Cpa to the arch. In the right side of the same specimen, only the thoracodorsal nerve (Ntd) was distributed into Lpa, whereas in the left side, only Npc supplied branches to Lpa. 3) The axillary arch was classified into 8 types based on the form and the supplying nerve of Cpa and Lpa. Cpa consisting of the muscle bundle is Type I, and Cpa consisting of the tendinous arch is Type II. We proposed that only Type II-A, with Cpa as tendinous arch and no Lpa, be designated as Taa (found in two cases), and the others as Maa. The following types were found in this study: Type I-A, consisting of only Cpa supplied by Npc (two cases); Type I-D, consisting of Cpa supplied by Npc and Lpa supplied by Ntd (one case); Type II-B, consisting of the tendinous arch and Lpa supplied by Npc (one case); Type II-D, consisting of the tendinous arch and Lpa supplied by Ntd (one case). 4) From the above findings, it can be suggested that Maa of varying shapes have been formed by a portion of the latissimus dorsi muscle supplied by Ntd, together with the pectoralis subcutaneous muscle, consisting of the pectoralis abdominalis, humeroabdominalis, humerodorsalis and ventrolateralis muscles supplied by Npc. The latter three muscles were proposed by Ura (1937) as the panniculus carnosus muscle, which was well developed in some lower mammalian orders. However, early investigators suggested that Maa was derived from the panniculus. Maa might have occurred as a rudimentary phylogenetic remainder in an early human embryonic stage.

Aged↗
PubMed2005

Histamine contributes to ischemia-related activation of cardiac spinal afferents: role of H1 receptors and PKC.

Myocardial ischemia activates cardiac spinal afferents that transmit the nociceptive information leading to chest pain and elicit excitatory cardiovascular reflexes. Previous studies have shown that histamine is increased in coronary sinus blood during myocardial ischemia and that this autacoid stimulates abdominal visceral afferents. The present investigation evaluated the role of endogenous histamine in stimulation of ischemically sensitive cardiac spinal afferents. Nerve activity of single-unit cardiac afferents was recorded from the left sympathetic chain or rami communicans (T2-T5) in anesthetized cats. Sixty-four cardiac afferents were identified. Injection (5-30 microg/kg) of histamine into the left atrium (LA) stimulated 7 ischemically sensitive cardiac afferents resulting in a significant increase in their activity in a dose-dependent manner. Also, LA injection of histamine (10 microg/kg) stimulated 7 of 8 ischemically insensitive cardiac spinal afferents. Administrations of 2-(3-chlorophenyl)histamine (250 microg/kg, LA), a specific H1 receptor agonist and histamine (10 microg/kg, LA), stimulated 9 other ischemically sensitive cardiac afferents (0.48 +/- 0.10 to 1.40 +/- 0.20 imp/s). In contrast, dimaprit (500 microg/kg, LA), an H2 receptor agonist, stimulated only one of the 9 afferents and thus did not alter their overall activity (0.40 +/- 0.09 to 0.54 +/- 0.09 imp/s). (R)alpha-Methyl-histamine (500 microg/kg, LA), an H3 receptor agonist, did not stimulate any of the 9 afferents. Pyrilamine (300 microg/kg, i.v.), a selective H1 receptor antagonist, attenuated the activity of 8 afferents during 5 min of ischemia from 3.32 +/- 0.38 to 1.87 +/- 0.28 imp/s and abolished the response of 9 other cardiac afferents to histamine. Finally, administration of PKC-(19-36) (30 microg/kg, i.v.), a selective inhibitor of protein kinase C, attenuated the response of 8 cardiac afferents to histamine by 32%. These data indicate that endogenous histamine contributes to activation of cardiac sympathetic afferents during myocardial ischemia through H1 receptors and that the action of histamine on these cardiac afferents is partially dependent on the intracellular PKC pathway.

Afferent Pathways↗
PubMed1976

Carotid sinus, aortic and subclavian baroreceptor activities during cardiopulmonary bypass in rabbits.

10Carotid sinus (SIN), aortic (AO) and subclavian (SUB) baroreceptor activities were recorded from intact nerves during experiments using cardiopulmonary bypass in 11 rabbits. These activities (number of impulses/second) were expressed as a percentage of basal activity observed before artificial circulation (AC). The preparation remained in a relative, "stable period" for up to 45 minutes. Then, a progressive decrease occurred in maximal arterial pressure (AP max) in the 11 experiments (fig. 2,4). 20 According to the level of arterial pressure the "stable period", our experiments can be divided into two groups: a) Group I (6 rabbits) with AP max greater than or equal 90 mm Hg; in this group, the correlation coefficients between pressure levels and nervous activities calculated during the period 0-70 min after the onset of AC, were positive (fig. 3) and statistically significant, as we could expect (AO, p less than 0.02; SIN, p less than 0.01; SUB, p less than 0.01). b) Group II (5 rabbits) with AP max less than 90 mm Hg; surprisingly, in this group no positive correlation was found between levels and nervous activities, which were generally very high (fig. 5). 30 Experiments were performed in 18 other rabbits in order to check the nature of the higher activities recorded in group II. These high activities were not of chemoreceptor or efferent origin, and, thus, were thought to be indeed really from baroreceptive fibres. 40 Ten experiments under AC were carried out to test the reactivity of baroreceptors in response to induced increase and decrease of pressure. The responses were qualitatively normal (i.e. an increase of pressure produced an increase in the nervous discharge), but in group II, the operative point was set at a higher level (fig. 6). 50 A possible, time-dependent, shift in the baroreceptor response curve under AC can account for these findings by giving, in some cases the illusion of a negative correlation between baroreceptor activity and arterial pressure (fig. 8). 60 The above mentioned shift in the baroreceptor response curve could be related to a change in sympathetic control of baroreceptors,resulting in a higher activity, and initiating and/or maintaining hypotension.

Animals↗
PubMed1988

Integration of gut function by sympathetic reflexes.

1. The spinal sympathetic outflow that innervates the gastrointestinal tract, including its blood vessels, has an impressive representation quantitatively, yet little is known about the functions of this system and its peripheral or central organization. Electrical stimulation or section of the splanchnic nerves have variable effects on the GI tract and does not, therefore, lead to a deeper understanding of the system. 2. The targets of the sympathetic supply of the GI tract are blood vessels, nonvascular (sphincteric) smooth musculature, myenteric neurones, submucous neurones and gut associated lymphoid tissues. The corresponding functions associated with these targets are regulation of blood flow (particularly through the mucosa) and resistance to flow, of motility, of secretion and absorption and of immune responses. Little is known about the effects of the sympathetic nervous system on the latter function. 3. The sympathetic postganglionic neurones are (at least in the guinea-pig) neurochemically characterized with respect to the targets. Neurones projecting to blood vessels contain neuropeptide Y in addition to noradrenaline, while neurones projecting to the submucous plexus contain somatostatin. No neuropeptide has been detected to date in neurones projecting to the myenteric plexus. 4. Transmission through guinea-pig prevertebral ganglia in vitro have been studied electrophysiologically. The following functions have been demonstrated: (a) transmission and distribution of preganglionic impulse activity to the targets in a relay-like fashion; (b) mediation of peripheral intestinointestinal reflexes between different sections of the GI tract; (c) integration of activity from the spinal cord and from various peripheral sources. The first function may apply particularly to the sympathetic pathway innervating blood vessels. Whether the second function occurs in vivo is questionable. The third function is the most important one for pathways involved in the regulation of motility and probably secretion and absorption. 5. Only limited information is available on preganglionic neurones projecting to prevertebral ganglia. Neurones regulating blood vessels are probably located in the intermediolateral cell column, and non-vascular visceral preganglionic neurones are situated medial to this cell column in the intermediate zone of the spinal cord. Vascular (vasoconstrictor) neurones exhibit a reflex pattern which is largely dependent on the brain stem. Spinal cord transection rostral to the sympathetic outflow causes an immediate abolition of basal and reflex activity in these neurones.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1993

Endoscopic procedures of the upper-thoracic sympathetic chain. A review.

The upsurge of endoscopic surgical procedures now includes procedures of the thoracic sympathetic chain. The number of articles on this issue is rapidly increasing. This article reviews the indications for as well as the technique, complications, side effects, and results of endoscopic upper-thoracic sympathetic ablation. Since 1977, nearly 900 cases have been described in the literature. The main indication is usually hyperhidrosis. The described techniques vary in detail, but the common denominators are simplicity, expedience, minimal surgical trauma, few complications, and low cost compared with standard methods of open surgery. The results are excellent, durable, and stand well compared with results of previous open techniques. Due to the overwhelming advantages of endoscopic methods, we can foresee an increasing adoption of these techniques and a subsequent relegation of the various open surgical procedures of the upper-thoracic sympathetic chain.

Humans↗
PubMed1997

Mutant molecular motors disrupt neural circuits in Drosophila.

A dominant negative mutation, Glued1, that codes for a component of the dynactin complex, disrupted the axonal anatomy of leg sensory neurons in Drosophila. To examine neuron structure in mutant animals, a P[Gal4] enhancer trap targeted expression of lacZ to the sensory neurons and thereby labeled neurons in the femoral chordotonal organ and their axons within the central nervous system. When these sensory axons were examined in the Glued1 mutant specimens, they were observed to arborize abnormally. This anatomical disruption of the sensory axons was associated with a corresponding disruption in a reflex. Normally, the tibial extensor motor neurons were excited when the femoral-tibial joint was flexed, but this resistance reflex was nearly absent in mutant animals. We used the P[Gal4] insertion strains to target expression of tetanus toxin light chain to these sensory neurons in wild-type animals and showed that this blocked the resistance reflex and produced a phenocopy of the Glued result. We conclude that disruption of the dynein-dynactin complex disrupts sensory axon path finding during metamorphosis, and this in turn disrupts synaptic connectivity.

Animals↗