Breast conservation surgery "BCS" for breast cancer.
Explore the source record for details and available documents.
Breast Neoplasms↗
Biomedical subjects
D A Hopkins
Publications and source records attributed to D A Hopkins.
Activity of in vivo atrial and ventricular neurons in chronically decentralized canine hearts.
The spontaneous activity of 175 neurons located in the ventral right atrial and ventral interventricular ganglionated plexi was recorded in eight anesthetized dogs, the hearts of which were chronically decentralized at least 2 wk before recordings were made. Ganglia were subsequently identified anatomically in the immediate vicinity of the recording sites. Spontaneous activity was correlated with the cardiac cycle in 57% of the atrial and 62% of the ventricular neurons and with the respiratory cycle in 29% of the atrial and 28% of the ventricular neurons. Spontaneous cardiovascular-related activity was recorded when systemic arterial pressure was between 80 and 175 mmHg. The activity of 23 atrial and 15 ventricular neurons was altered when discrete regions of the heart were mechanically distorted by gentle touch. These data imply that cardiac ganglionated plexi contain afferent neurons that receive inputs from limited regions of the heart. The spontaneous activity generated by intracardiac neurons was not altered when extracardiac tissues were distorted. These results demonstrate that neurons in ganglia on chronically decentralized hearts can generate spontaneous activity, a large fraction of which is correlated with cardiovascular or respiratory events.
Adipose Tissue↗
Adaptation of NASA technology for the optimum design of orthopedic knee implants.
NASA technology originally developed for designing aircraft turbine-engine blades has been adapted and applied to orthopedic knee implants. This article describes a method for tailoring an implant for optimal interaction with the environment of the tibia. The implant components are designed to control stresses in the bone for minimizing bone degradation and preventing failures. Engineers expect the tailoring system to improve knee prosthesis design and allow customized implants for individual patients.
Aerospace Medicine↗
Topography and synaptology of mamillary body projections to the mesencephalon and pons in the rat.
The anterograde and retrograde transport of horseradish peroxidase conjugated to wheat germ agglutinin (WGA-HRP) was used to study the anatomical organization of descending projections from the mamillary body (MB) to the mesencephalon and pons at light and electron microscopic levels. Injections of WGA-HRP into the medial mamillary nucleus resulted in dense anterograde and retrograde labeling in the ventral tegmental nucleus, while injections in the lateral mamillary nucleus resulted in dense anterograde labeling in the dorsal tegmental nucleus pars dorsalis and dense anterograde and retrograde labeling in the pars ventralis of the dorsal tegmental nucleus. Anterogradely labeled fibers in the mamillotegmental tract diverged from the principal mamillary tract in an extensive dorsocaudally oriented swath of axons which extended to the dorsal and ventral tegmental nuclei, and numerous axons turned sharply ventrally and rostrally to terminate topographically in the dorsomedial nucleus reticularis tegmenti pontis and rostromedial pontine nuclei. The anterograde labeling in these two precerebellar relay nuclei was distributed near the midline such that projections from the lateral mamillary nucleus terminated mainly dorsomedial to the terminal fields of projections from the medial mamillary nucleus. In the dorsal and ventral tegmental nuclei, labeled axon terminals contained round synaptic vesicles and formed asymmetric synaptic junctions primarily with small diameter dendrites and to a lesser extent with neuronal somata. A few labeled terminals contained pleomorphic vesicles and formed symmetric synaptic junctions with dendrites and neuronal somata. Labeled axon terminals were also frequently found in synaptic contact with retrogradely labeled dendrites and neuronal somata in the dorsal and ventral tegmental nuclei. These findings indicate that neurons in the dorsal and ventral tegmental nuclei are reciprocally connected with MB projection neurons. In the nucleus reticularis tegmenti pontis and medial pontine nuclei, labeled axon terminals contained round synaptic vesicles and formed asymmetric synaptic junctions primarily with small diameter dendrites. The present study demonstrates that projections from the medial and lateral nuclei of the MB are topographically organized in the mesencephalon and pons. The synaptic morphology of mamillotegmental projections suggests that they may have excitatory influences primarily on the distal dendrites of neurons in these brain regions.
Afferent Pathways↗
Activity of in vivo canine ventricular neurons.
The spontaneous activity of 113 neurons located in the ganglionated plexus in the epicardial fat overlying the cranial portion of the ventral intraventricular groove and the origin of the circumflex coronary artery was recorded in ten anesthetized dogs. Ganglia that contained varying numbers of neurons, some with two or more nucleoli, were subsequently identified anatomically in the vicinity of the recording sites. Spontaneous activity was correlated with the cardiac cycle in 81% and with the respiratory cycle in 17% of the identified neurons. The spontaneous cardiovascular-related activity occurred in relation to specific phases of the cardiac cycle when arterial pressure was between approximately 80 and 175 mmHg. When systolic pressures fell below approximately 80 mmHg or increased above approximately 175 mmHg, neurons displaying cardiovascular-related activity were inactive. The activity of 62% of all identified neurons was altered when discrete regions of the heart or pulmonary tissue were mechanically distorted by gentle touch. In many instances mechanical distortions of tissues were still able to alter neuronal activity following acute decentralization. Single stimuli or trains of stimuli delivered to the vagosympathetic complexes, stellate ganglia, or cardiopulmonary nerves generated bursts of activity in ganglionic neurons. Spontaneous activity occurred whether the ganglia were connected to the central nervous system or acutely decentralized. It is concluded that some neurons located on the canine ventricle display spontaneous activity that is related to cardiovascular or respiratory dynamics. The results also demonstrate that ventricular neurons can be influenced by sympathetic or parasympathetic efferent axons as well as cardiac mechanoreceptors.
Adipose Tissue↗
Activity of canine in situ left atrial ganglion neurons.
The responses of 135 spontaneously active neurons were recorded from ganglionated plexi located in the three epicardial fat pads on the ventral surface of the left atrium of ten dogs. Ganglia, some of which were adjacent to the recording sites, containing varying numbers of neurons were identified throughout these fat pads. Spontaneous activity in 50% of the identified neurons was correlated with specific phases of the cardiac cycle when arterial systolic pressure was between approximately 70 and 180 mmHg and in 28% it was correlated with the respiratory cycle. More neurons displaying cardiovascular-related activity were recorded when systolic pressure was increased after administration of positive inotropic agents or aortic occlusion. However, when systolic pressure increased above approximately 150 mmHg the number of active neurons decreased, and when pressure reached approximately 180 mmHg no activity was recorded. The activity of 36% of identified neurons was altered when discrete regions of the heart, great thoracic vessels, lungs, neck, upper limb, chest wall, or abdominal wall were mechanically distorted by gentle touch. After acute decentralization of the intrathoracic nervous system some neurons still displayed spontaneous cardiovascular- or respiratory-related activity. Single stimuli or trains of stimuli delivered to the vagosympathetic complexes, stellate ganglia, or cardiopulmonary nerves activated neurons in intact or acutely decentralized preparations. It is concluded that ventral left atrial ganglionated plexi neurons display activity related to cardiovascular or respiratory dynamics, and that these neurons are influenced by sympathetic and parasympathetic efferent axons, as well as by cardiac and other mechanoreceptors.
Adipose Tissue↗
Cardiac responses to electrical stimulation of discrete loci in canine atrial and ventricular ganglionated plexi.
The purpose of the present study was to examine cardiac effects induced by electrical stimulation (1-4 V, 1 ms, 200 Hz) of discrete loci within the ganglionated plexi located on canine atria and ventricles. When 20 loci in the right atrial ventral ganglionated plexi of 11 anesthetized open-chest dogs were stimulated, bradycardia and/or right and left atrial force suppression occurred when, on average, 15% of these loci were stimulated. Bradycardia and atrial force suppression were elicited when, on average, 8% of 15 loci in the left atrial ventral ganglionated plexi of eight dogs was stimulated. When these loci were restimulated after acute decentralization, cardiac responses were attenuated or occasionally eliminated. After atropine (1 mg/kg iv) administration, repeat stimulation of loci in the right but not left atrial ganglionated plexus induced tachycardia. Stimulation of loci in the right ventricular ganglionated plexus after the subsequent administration of desipramine (1 mg/kg iv) in six dogs resulted in an increase in right ventricular conus intramyocardial pressure. After hexamethonium administration (10 mg/kg iv, followed by a continuous infusion of 1 mg.kg-1.min-1), sympathetic responses were no longer elicited from one of the five dogs in which loci in the right atrial ganglionated plexi and from two of the six dogs in which loci of the right ventricular ganglionated plexus had elicited responses. We conclude that atrial and ventricular ganglionated plexi contain efferent parasympathetic, efferent sympathetic, and afferent neurons.
Animals↗
Mamillary body in the rat: topography and synaptology of projections from the subicular complex, prefrontal cortex, and midbrain tegmentum.
The retrograde and anterograde transport of horseradish peroxidase conjugated to wheat germ agglutinin (WGA-HRP) has been used to trace afferent connections of the rat mamillary body (MB) at the light and electron microscopic levels. Injections of WGA-HRP into different parts of the MB resulted in heavy retrograde labeling in the subicular complex, medial prefrontal cortex, and dorsal and ventral tegmental nuclei. Injections of WGA-HRP into each of these brain regions, respectively, resulted in anterograde labeling with specific distributions and characteristic synaptic organizations in the MB. Projections from the rostrodorsal and caudoventral subiculum terminated in a topographically organized laminar fashion in the medial mamillary nucleus bilaterally, whereas afferent projections from the presubiculum and parasubiculum terminated only in the lateral mamillary nucleus. Labeled axon terminals which originated from the subicular complex were characterized by round vesicles and formed asymmetric synaptic junctions with small-diameter dendrites and dendritic spines in the medial and lateral mamillary nuclei. Projections from the prefrontal cortex originated mainly in the infralimbic area and to a lesser degree in the prelimbic and anterior cingulate areas. Injections of tracer into these brain regions gave rise to dense labeling of axon terminals in the medial mamillary nucleus, pars medianus, and in the anterior dorsomedial portion of the pars medialis. The labeled terminals were characterized by round vesicles and formed asymmetric synaptic junctions with small-diameter dendrites and dendritic spines. Projections from the dorsal tegmental nucleus terminated in the ipsilateral lateral mamillary nucleus, whereas afferent projections from the anterior and posterior subnuclei of the ventral tegmental nucleus terminated topographically in the medial mamillary nucleus. The ventral tegmental nucleus, pars anterior projected to the midline region of the medial nucleus and the dorsolateral and ventromedial subdivisions of the pars posterior projected to medial and lateral parts of the medial nucleus, respectively. In contrast to the synaptic morphology of subicular complex and medial prefrontal cortex axon terminals in the MB, labeled axon terminals in the MB which originated from the midbrain tegmentum were characterized by pleomorphic vesicles and formed symmetric synaptic junctions with neuronal somata and proximal dendrites as well as distal dendrites and dendritic spines.(ABSTRACT TRUNCATED AT 400 WORDS)
Afferent Pathways↗
Viscerotopic representation of the upper alimentary tract in the rat: sensory ganglia and nuclei of the solitary and spinal trigeminal tracts.
The aim of this study was to map the viscerotopic representation of the upper alimentary tract in the sensory ganglia of the IXth and Xth cranial nerves and in the subnuclei of the solitary and spinal trigeminal tracts. Therefore, in 172 rats 0.5-65 microliters of horseradish peroxidase (HRP), wheat germ agglutinin-HRP, or cholera toxin-HRP were injected into the trunks and major branches of the IXth and Xth cranial nerves as well as into the musculature and mucosa of different levels of the upper alimentary and respiratory tracts. The results demonstrate that the sensory ganglia of the IXth and Xth nerves form a fused ganglionic mass with continuous bridges of cells connecting the proximal and distal portions of the ganglionic complex. Ganglionic perikarya were labeled in crude, overlapping topographical patterns after injections of tracers into nerves and different parts of the upper alimentary tract. After injections into the soft palate, pharynx, esophagus, and stomach, anterograde labeling was differentially distributed in distinct subnuclei in the nucleus of the tractus solitarius (NTS). Palatal and pharyngeal injections resulted primarily in labeling of the interstitial and intermediate subnuclei of the NTS and in the paratrigeminal islands (PTI) and spinal trigeminal complex. Esophageal and stomach wall injections resulted in labeling primarily of the subnucleus centralis and subnucleus gelatinosus, respectively. The distribution of upper alimentary tract vagal-glossopharyngeal afferents in the medulla oblongata has two primary groups of components, i.e., a viscerotopic distribution in the NTS involved in ingestive and respiratory reflexes and a distribution coextensive with fluoride-resistant acid-phosphatase-positive regions of the PTI and spinal trigeminal nucleus presumably involved in visceral reflexes mediated by nociceptive or chemosensitive C fibers.
Animals↗
Ganglionic distribution of afferent neurons innervating the canine heart and cardiopulmonary nerves.
The ganglionic distribution of the perikarya of afferent axons in cardiopulmonary nerves or the heart was studied in 64 dogs by injecting horseradish peroxidase into physiologically identified cardiopulmonary nerves or different regions of the heart. In 6 additional dogs, horseradish peroxidase was injected into the aortic arch, pericardial sac, left ventricular cavity or the skin. After injections into cardiopulmonary nerves, retrogradely labeled perikarya were found in the ipsilateral nodose ganglion and the ipsilateral C7-T7 dorsal root ganglia. After injections into different regions of the heart, retrogradely labeled neurons were found in the nodose ganglia bilaterally and in the C6-T6 dorsal root ganglia bilaterally. Many more retrogradely labeled neurons were found in the nodose ganglia in comparison to the dorsal root ganglia. The largest numbers of retrogradely labeled perikarya in the dorsal root ganglia occurred in the T 2-4 ganglia following nerve or heart injections. Following injections into specific regions of the heart or individual physiologically identified cardiopulmonary nerves, regional distributions of labeled neurons could not be identified within or among ganglia with respect to the structures injected. Perikarya in dorsal root ganglia which were labeled after heart injections ranged in area from 436-3280 microns 2 (X = 1279 +/- 51 S.E.M.) while after skin injections labeled perikarya ranged in area from 224-5701 microns 2 (X = 1631 +/- 104 S.E.M.). The results show that the afferent innervation of the canine heart is provided by neurons located throughout the nodose ganglia and to a lesser degree in the C6-T6 dorsal root ganglia bilaterally. The bilateral distribution of cardiac afferent neurons raises questions regarding mechanisms underlying unilateral symptoms frequently associated with heart disease.
Animals↗
Mamillary body in the rat: a cytoarchitectonic, Golgi, and ultrastructural study.
The present study provides a comprehensive light and electron microscopic analysis of the anatomical organization of the rat mamillary body. The cytoarchitecture and morphology of mamillary neurons were investigated with the aid of Nissl-stained and Golgi-impregnated sections cut in transverse, horizontal, and sagittal planes. The ultrastructural features of the mamillary nuclei were correlated with observations made on Golgi material. The mamillary body is comprised of a lateral and a medial nucleus, the latter being subdivided into five major subnuclei: pars lateralis, pars basalis, pars medialis, pars medianus, and pars posterior. The perikarya are medium-sized or small with the proportions of each differing among subnuclei. The largest perikarya are found in the lateral mamillary nucleus (cell area 257.0 microns2) and have 2-5 radially oriented aspiny dendrites that are often beaded. Small cells predominate in the pars lateralis (cell area 116.3 microns2) and pars basalis (cell area 118.3 microns2), whereas the pars medialis (cell area 196.7 microns2), pars medianus (cell area 136.5 microns2), and pars posterior (cell area 154.6 microns2) contain mainly medium-sized cells. The dendrites of most cells in the medial nucleus are radially oriented and exhibit a variety of spines including numerous short stubby spines, spines with thin necks that end in spherical swellings, and long thin spines. Neuronal somata are often closely apposed with no intervening glial processes and contain eccentrically located nuclei with one or more invaginations of the nuclear envelope. Two main classes of axon terminals were identified in the mamillary body. One type contains round vesicles and forms asymmetric synaptic junctions (RA) with dendrites and dendritic spines. RA terminals rarely contact neuronal somata and proximal dendrites in the MB. The second type contains pleomorphic vesicles and forms mainly symmetric synaptic junctions (PS) with neuronal somata as well as dendrites and spinous processes. Dense-cored vesicles were frequently seen in both types of terminals. Both types of terminals often synapse with two adjacent dendrites and are also found near or adjacent to each other on the same dendrite. A quantitative analysis indicated that the numbers of RA terminals in the medial nucleus almost equals the numbers of PS terminals, whereas the lateral mamillary nucleus contains considerably more PS (64%) than RA terminals (36%).
Animals↗
Activity of in vivo canine cardiac plexus neurons.
The activity of 394 spontaneously active neurons located in the ganglionated plexus of the ventral epicardial fat pad overlying the right atrium and pulmonary veins was recorded. Ganglia that contained various numbers of neurons, many with two or more nucleoli, were identified adjacent to the recording sites. Spontaneous activity was correlated with the cardiac cycle in 39% and with the respiratory cycle in 8% of the identified neurons. Neuronal activity occurred in specific phases of the cardiac cycle when arterial pressure was between approximately 70 and 175 mmHg. During increases in systolic pressure induced by positive inotropic agents or aortic occlusion, responses of neurons that displayed cardiovascular-related activity were enhanced. These responses persisted after acute decentralization. The activity of 14% of all identified neurons was altered when discrete regions of the heart, great thoracic vessels, or lungs were mechanically distorted by gentle touch. Trains of stimuli, but not single stimuli, delivered to the vagosympathetic complexes, stellate ganglia, or cardiopulmonary nerves activated ganglionic neurons in intact or acutely decentralized preparations. It is concluded that the activity of some cardiac ganglion neurons is related to cardiovascular or respiratory dynamics and that some of these neurons receive inputs from sympathetic and parasympathetic efferent axons as well as from cardiac mechanoreceptors.
Adipose Tissue↗
Viscerotopic representation of the upper alimentary tract in the medulla oblongata in the rat: the nucleus ambiguus.
The nucleus ambiguus has been reported to innervate various thoracic and abdominal viscera in addition to the musculature of the upper alimentary tract. However, the literature is contradictory as to how different regions of the nucleus ambiguus innervate specific organs. Therefore, a systematic investigation of the viscerotopic organization of the nucleus ambiguus was undertaken. In 102 rats, 0.5-10.0 microliter of HRP, WGA-HRP, cholera toxin-HRP or fluorescent tracers were injected into the IXth, Xth, and XIth cranial nerves and the major branches of the Xth as well as organs supplied by them. The results demonstrate that the nucleus ambiguus in the rat is made up of two major longitudinal divisions: a dorsal division comprised of three rostrocaudally aligned subdivisions representing the special visceral efferent component, and a ventral division comprised of at least two subdivisions representing the general visceral efferent component. The dorsal division corresponds to the nucleus ambiguus in the narrow sense and comprises a rostral esophagomotor compact formation, an intermediate pharyngolaryngomotor semicompact formation, and a caudal laryngomotor loose formation. Each of these formations displays a characteristic dendroarchitecture. The stylopharyngeal and cricothyroid motoneurons are displaced rostrad from the main pharyngeal and laryngeal motoneuronal pools. Thyropharyngeal (lower constrictor) motoneurons occupy the rostral half of the semi-compact formation and hyopharyngeal (middle constrictor) motoneurons its entire length. The ventral division of the nucleus ambiguus corresponds to the external formation, extends along the entire length of the medulla oblongata, and contains preganglionic neurons innervating the heart and supradiaphragmatic structures innervated by the glossopharyngeal and the superior laryngeal nerves.
Animals↗
Distribution of neuropeptide-like immunoreactivity in intact and chronically decentralized middle cervical and stellate ganglia of dogs.
Neuropeptide-like immunoreactivity to antisera raised against Leu- and Met-enkephalin, vasoactive intestinal peptide (VIP), neuropeptide Y (NPY) and substance P (SP) have been studied immunohistochemically in middle cervical and stellate ganglia of dogs. To investigate the relationship of the peptides to one another as well as to preganglionic and postganglionic neurons, intact and chronically decentralized middle cervical and stellate ganglia were studied. Ganglia were processed for immunohistochemistry in unoperated dogs and in dogs two weeks after unilateral ganglionic decentralization. The immunoreactivity for each peptide had a characteristic distribution in the ganglia. These distributions differed from one another and from the distribution of cardiac postganglionic sympathetic neurons. Camera lucida drawings of peptide distributions were made to compare different peptides and counts were made to determine the percentages of cells immunoreactive for a given peptide. The results demonstrated that enkephalin-like immunoreactivity in axons was present in both the stellate and middle cervical ganglia, but was heaviest in the caudal 2/3 of the stellate ganglia. Enkephalin-like immunoreactive fibers formed pericellular baskets around stellate ganglion neurons. VIP-like immunoreactive cell bodies and processes were distributed sparsely, but widely, in the stellate ganglia and to a lesser extent in the middle cervical ganglia. One of two commercial antisera to SP resulted in immunoreactive staining of cell bodies and processes in the stellate ganglia. SP-like immunoreactivity in neurons represented about 10% or less of the cells in the stellate ganglia. At least 80-85% of the neurons in the stellate and middle cervical ganglia were immunoreactive for NPY antisera. Decentralization eliminated enkephalin-like immunoreactive staining in the middle cervical and stellate ganglia, but not the VIP-, NPY- and SP-like immunoreactive staining of neurons in these ganglia. In summary, the enkephalin-like immunoreactive axons in the thoracic autonomic ganglia appear to be derived from extrinsic neurons, most likely from preganglionic spinal neurons. VIP-, SP- and NPY-like immunoreactivity were not significantly affected by decentralization. The results provide anatomical evidence for substrates related to neuropeptidergic synaptic mechanisms in thoracic autonomic ganglia.
Animals↗
Re-investigation of the innervation of the thymus gland in mice and rats.
Central to the postulated relationship between the brain and the immune system has been evidence for the direct neural innervation of primary organs of the immune system. It has been reported previously that the thymus gland in rats and mice receives a substantial innervation from the "retrofacial" nucleus of the brain stem and ventral horn cells of the upper cervical spinal cord. Based on the proximity of the thymus to thoracic viscera and neck musculature known to receive motor fibers from these same areas of the brain stem and spinal cord, we examined the possibility that retrogradely labeled cells in the brain stem and spinal cord following injections of tracers into the thymus are due to spread of tracer into the esophagus and neck musculature. Small injections (0.5-2.0 microliter) of wheatgerm agglutinin-horseradish peroxidase (WGA-HRP) were made into the thymus, the esophagus, and the longus colli muscle of rats or mice. Also, the effects of a unilateral cervical vagotomy on cholinesterase activity in the thymus were examined. Finally, the source of the sympathetic supply to the thymus and the presence of catecholamine and cholinesterasic fibers in the thymus was reassessed. Injections of WGA-HRP into the thymus produced little or no labeling in the brain stem and spinal cord. In contrast, control injections into the esophageal wall resulted in numerous intensely labeled cells in the compact formation of the nucleus ambiguus, irrespective of the rostral-caudal level of the esophageal injection. Similarly, tracer injections into the longus colli muscle resulted in numerous intensely labeled cells in the ventral horn of the upper cervical spinal cord. Unilateral vagotomy did not alter cholinesterase activity in the thymus even though it was largely depleted in the ipsilateral nucleus ambiguus. The histochemical studies verified a major sympathetic innervation of the thymus gland. In keeping with this result, in animals in which no labeled cells were observed in the brain stem or spinal cord following thymus injection, labeled cells were, however, observed in the sympathetic chains from the superior cervical ganglia caudal to the T3 ganglia. In summary, all labeled cells in the brain stem and cervical spinal cord observed following tracer injections into the thymus can be accounted for by spread of the tracer into surrounding structures, leading to spurious labeling.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Anatomy of human extrinsic cardiac nerves and ganglia.
The anatomy of the human extrinsic cardiac nerves and ganglia was reinvestigated because descriptions of human cardiac innervation vary, detailed analyses of subhuman mammalian cardiac innervation reveal considerable similarities among species and the anatomic pattern of cardiac innervation observed in subhuman mammals differs significantly from those described for humans. The presence of a consistent pattern of cardiac innervation in subhuman mammals raised the question as to whether a similar pattern exists in humans. To investigate this, the cervical and thoracic autonomic nerves and ganglia were dissected in 13 embalmed and 10 autopsy cadavers. All major sympathetic cardiopulmonary nerves were found to arise from the stellate ganglia and the caudal halves of the cervical sympathetic trunks below the level of the cricoid cartilage. These sympathetic cardiopulmonary nerves usually consisted of 3 nerves on the right side and 4 on the left. In contrast to widely accepted reports, no sympathetic cardiopulmonary nerves were found to arise from the superior cervical ganglia or the thoracic sympathetic trunks inferior to the stellate ganglia. Parasympathetic cardiopulmonary nerves were found to arise from the recurrent laryngeal nerves and the thoracic vagi immediately distal to them. These nerves interconnected with sympathetic cardiopulmonary nerves anterior and posterior to the main pulmonary artery to form the ventral and dorsal cardiopulmonary plexuses. These plexuses contained relatively large discrete nerves as well as smaller interconnections. Emerging from these plexuses to innervate the ventricles were 3 distinct relatively large cardiac nerves, the right and left coronary cardiac nerves and the left lateral cardiac nerve. In addition to these 3 major nerves, small cardiac nerves arose from the plexuses and the thoracic vagi. Histologic examination of representative dissections confirmed the presence of neural tissue and identified the locations of neuronal cell bodies in these structures. Cell bodies were located in the nodose, superior cervical, middle cervical, stellate and thoracic sympathetic ganglia. The middle cervical ganglia varied in size and number. Neuronal cell bodies were found in the cervical and thoracic sympathetic trunks and in small mediastinal ganglia located along the courses of the cardiopulmonary and cardiac nerves. Marked similarities exist between the anatomy of the cardiopulmonary nerves and ganglia of humans and baboons.
Adult↗
Observations on the afferent and efferent organization of the vagus nerve and the innervation of the stomach in the squirrel monkey.
Horseradish peroxidase was injected into the cervical vagus nerve or stomach wall of adult squirrel monkeys. Following cervical vagus nerve injections, labelled afferent fibres were present in the tractus solitarius and labelled fibres and terminals were present in medial and lateral parts of the nucleus of the tractus solitarius (NTS) ipsilaterally. Afferent labelling was also seen in the ipsilateral commissural nucleus and in the area postrema. Labelling was present contralaterally in caudal levels of the medial parts of the NTS, in the commissural nucleus, and in the area postrema. Afferent projections to the ipsilateral pars interpolaris of the spinal trigeminal nucleus and to the substantia gelatinosa of the C1 segment of the spinal cord were also labelled. Following injections of HRP into the anterior and posterior stomach walls, the tractus solitarius was labelled bilaterally. Afferent labelling was concentrated bilaterally in the dorsal parts of the medial division of the NTS, i.e., in the subnucleus gelatinosus, and in the commissural nucleus. The regions of NTS immediately adjacent to the tractus solitarius were largely unlabelled. Injections of HRP into the cervical vagus nerve resulted in heavy retrograde labelling of neurons in the ipsilateral dorsal nucleus of the vagus (DMX) and in the nucleus ambiguus (NA). In addition a few neurones were labelled in the intermediate zone between these two nuclei. Retrogradely labelled neurons were also present in the nucleus dorsomedialis in the rostral cervical spinal cord and in the spinal nucleus of the accessory nerve. Injections of HRP into the left cricothyroid muscle in two cases resulted in heavy retrograde labelling of large neurons in the left NA. Following stomach wall injections of HRP retrograde labelling of neurons was seen throughout the rostrocaudal and mediolateral extent of the DMX; there was no apparent topographical organization of the projection. In these cases, a group of labelled smaller neurons was found lying ventrolateral to the main part of the NA through its rostral levels. This study in a primate indicates that a large vagal afferent projection originates in the stomach wall and terminates primarily in the subnucleus gelatinosus of the NTS and in the commissural nucleus with a distribution similar to that described previously in studies in several subprimate mammalian species. The present results and those of other studies suggest some degree of segregation of visceral input within different subnuclei of the NTS.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Ultrastructure of the dorsal motor nucleus of the vagus nerve in monkey with a comparison of synaptology in monkey and cat.
Neurons of the dorsal motor nucleus of the vagus nerve were studied following injections of horseradish peroxidase into the vagus nerve in a monkey (Macaca fascicularis). In frozen sections, the dorsal motor nucleus appeared to be completely filled by labeled medium-sized (20-30 micron in long axis) neurons. Labeled dendrites from these neurons often extended outside the borders of the nucleus into the nucleus of the tractus solitarius. In 1 micron thick plastic sections and ultrathin sections of the dorsal motor nucleus, two distinct types of neurons were observed with the light and electron microscope. Medium-sized neurons with abundant cytoplasm and an oval nucleus were retrogradely labeled with HRP, while small (10-15 micron in long axis) neurons with a paucity of organelles and an invaginated nucleus remained unlabeled. Medium-sized neurons outnumbered the small neurons by approximately five to one. The synaptic organization of the dorsal motor nucleus in monkey was studied and compared with that in cat. The porportions of different types of axosomatic synapses were similar in both species. Terminals containing round vesicles and making symmetrical or asymmetrical contact with the postsynaptic structure were more common than synaptic terminals containing pleomorphic vesicles. In both species, there was a slightly greater synaptic density on the medium-sized neurons than on the small neurons. The synaptic density in the monkey dorsal nucleus was greatest on the smallest dendrites in the neuropil and least on the somata.
Animals↗