Reorganization of peptidergic systems during brain regeneration in Eisenia fetida (Oligochaeta, Annelida)

After the extirpation of the brain reorganization of the peptidergic (FMRFamide, neuropeptide Y, proctolin) systems was studied in the newly forming cerebral ganglion of the annelid Eisenia fetida. During regeneration, all immunoreactive fibres appear on the 1st-2nd postoperative day. At the beginning of regeneration, immunoreactive neurons and fibres form a mixed structure in the wound tissue. On the 3rd postoperative day, FMRFamide positive and neuropeptide Y-immunoreactive, while on the 7th postoperative day proctolin-immunoreactive neurons appear in the loose wound tissue. From the 25th postoperative day a capsule gradually develops around it. The neurons of the preganglion move to the surface of the newly appearing preganglion. The number of these cells gradually increase, and by the 72th-80th postoperative days the localization and number of peptide-immunoreactive neurons is similar to that in the intact one. The neurons of all examined peptidergic systems may originate from the neuroblasts, situated on the inner and outer surface of the intact ganglia (e.g. suboesophageal and ventral cord ganglia). In addition FMRFamide and proctolin immunoreactive neurons may take their derive by mitotic proliferation from the pharyngeal neurons, too.     

Time of origin of cells in the histiogenesis of the spinal cord]

In order to establish the moment of appearance of neuroblasts and ectoglia of the spinal cord the autoradiographic study with the use of H3-thymidine and C14-thmidine injected to pregnant mice with the intervals between injections 121/2 or 24 hours was undertaken. It was establised that spinal neurons were removed from the nervous tube beginning from the 10th up to 13th days of embroyogenesis. The motoneurons of the anterior horn were the first to appear (10th-12th days), the neurons of the intermideate zone were the next to appear (11th - 12th days) and the last were the neurons of posterior horn (13th day). Beginning from the 13th day of embryogenesis there appeared the ectoglia which migrated following meurblasts two days later. The saturation of the grey matter with glial cells and the saturation of the white matter with Schwann cells was brought about by means of additional multiplication at the site of the glioblasts removed from the nervous tube. The main function of the matrix layer neuroepithelium of the nervous tube as a provider of cells to the spinal cord terminated on the 15th day of embryogenesis.     

The development of the neurons of the glossopharyngeal (IX) and vagal (X) sensory ganglia in chick embryos

The timetable of cell generation, neuronal death and neuron numbers in the fused proximal glossopharyngeal (IX) and vagal (X) ganglion and distal IX and X ganglia were studied in normal and nerve growth factor (NGF) treated chick embryos. 3H-thymidine was injected between the 3rd and 7th days of incubation and embryos sacrificed on the 11th day. Neurons in the distal IX and X ganglia were generated between the 2nd and 5th days of incubation, the peak mitotic activity occurring on the 4th and 3rd days, respectively. Neurons of the proximal IX and X ganglion were generated between the 4th and 7th days, with maximum neuron generation on the 5th day of incubation. Counts of neurons in the 3 ganglia between the 5th and 18th days of incubation showed a maximum of 22,000 on the 8th day in the proximal IX and X ganglion and this decreased to 12,000 by the 13th day. In the distal IX ganglion, the neuron number decreased by 44% from 4,500 on the 6th day to 2,500 by the 11th day. A similar decrease of 43% was found in the distal X ganglion, the neuron number falling from 11,500 on the 7th day to 6,500 by the 11th day of incubation. Neuronal cell death in these ganglia extended from the 5th to the 12th day of incubation, maximum cell death occurring at or after the cessation of mitotic activity. NGF administration from the 5th to the 11th day of incubation did not have a measurable effect on the neurons of proximal IX and X and distal IX ganglia, but increased neuronal survival by 30% in the distal X ganglion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reorganization of monoaminergic systems in the earthworm,Eisenia fetida,following brain extirpation

The present study describes the major aspects of how monoaminergic (serotonin, dopamine) systems change in the course of regeneration of the brain in the earthworm (Eisenia fetida), investigated by immunocytochemistry, HPLC assay, and ligand binding. Following brain extirpation, the total regeneration time is about 80 days at 10 degrees C. On the 3rd postoperative day serotonin, and on the 11th postoperative day tyrosine hydroxylase-immunoreactive neurons can be observed in the wound tissue. Thereafter the number of the immunoreactive cells increases gradually, and by the 76th-80th postoperative days all serotonin- and tyrosine hydroxylase-immunopositive neurons can be found in their final positions, similarly to those observed in the intact brain. Labeled neurons located in the dorsal part of the regenerated brain appear earlier than the cells in lateral and ventral positions. Both serotonin- and tyrosine hydroxylase-immunoreactive neurons of the newly formed brain seem to originate from undifferentiated neuroblasts situated within and around the ventral ganglia and the pleura. Dopaminergic (tyrosine hydroxylase-immunoreactive) elements may additionally derive from the proliferation of neurons localized in the subesophageal ganglion and the pharyngeal nerve plexus. Following brain extirpation, both serotonin and dopamine levels, assayed by HPLC, first increase in the subesophageal ganglion; by the 25th day of regeneration, the monoamine content decreases in it and increases in the brain. Hence it is suggested that monoamines are at least partly transported from this ganglion to the regenerating brain. At the same time, (3)H-LSD binding can be detected in the regenerating brain from the 3rd postoperative day, showing a continuous increase until the 80th postoperative day, suggesting a guiding role of postsynaptic elements in the monoaminergic reinnervation of the newly formed brain.     

Quantitative study on the fetal cervical dorsal root ganglion and observations on its relationship with the spinal nerve complex in the albino mouse

In mouse fetuses aged 12, 14, 16, 18 and 20 days, the cervical dorsal root ganglion was studied quantitatively. The main growth in volume of the interneuroblastic spaces was between the 12th and 16th day of pre-natal life while the main increase in volume of its neuroblasts occurred in the subsequent 4 days. Thus, it was postulated that the growth and branching of the neuroblastic dendrites, growth of the neuroglial elements and the vascular ramifications inside the ganglion occurred mainly between the 12th and 16th day of pre-natal life. Different modalities in the spatial relationship between the dorsal root ganglion and the different components of the spinal nerve were met with. At times, the trunk of the spinal nerve was located inside the ganglion. At that site, the posterior primary ramus emerged from it and appeared as a branch of the ganglion. The ventral root sometimes passed close to the fibrous capsule of the ganglion. In other cases, it passed inside the ganglion, dividing the ganglionic neuroblasts into dorsal and ventral groups. These either remained ensheathed by one fibrous capsule or became divided into two separate masses that remained connected to each other by the fibrous dural sheath.     

Formation and specification of neurons during the development of the leech central nervous system

In the leech embryo, neurogenesis takes place within the context of a stereotyped cell lineage. The prospective germ layers are formed during the early cleavage divisions by the reorganization and segregation of circumscribed domains within the cytoplasm of the fertilized egg. The majority of central neurons arise from the ectoderm, and central neuroblasts are distributed throughout both the length and width of each ectodermal hemisegment. Much of the segmental ganglion arises from medial neuroblasts, but there are also lateral ectodermal neuroblasts and mesodermal neuroblasts that migrate into the nascent ganglion from peripheral sites of origin. Some of these migratory cells are committed to neurogenesis prior to reaching their central destination. In addition, the leech embryo exhibits a secondary phase of neurogenesis that is restricted to the two sex segment ganglia. Secondary neurogenesis requires that a mitogenic or trophic signal be conveyed from the peripherally located male sex organ to a particular set of centrally located neuroblasts, apparently via already differentiated central neurons that innervate the sex organ. The differential specification of neuronal phenotypes within the leech central nervous system occurs in multiple steps. Some aspects of a neuron's identity are already specified at the time of its terminal cell division and would seem to involve the lineal inheritance of developmental commitments made by one of the neuron's progenitors. This lineage-based identity can then be modified by interactions between the postmitotic neuron and other neurons or non-neuronal target cells encountered during its terminal differentiation. © 1995 John Wiley & Sons, Inc.     

Structural metabolic processes in the skeletal muscle tissue of chick embryos administered actinomycin D

The development of the skeletal muscle tissue has been studied cytophotometrically, electron microscopically and radioautographically at administration of actinomycin-D (0.2 mcg/g) to the 11- and 15-day-old chick embryos). Different character of restorative processes under the conditions when RNA synthesis is disturbed by actinomycin-D administration is noted: before morphologically distinguished myosatellites appear (before the 13th-14th day of embryogenesis) and after myosatellites appearance (from the 14th-15th day of development). Evidently, the myosatellites are the muscle cells resistive to certain external factors, they ensure an effective adaptation of the skeletal muscle tissue to unfavourable effects. When the satellite cells appear, the skeletal muscle tissue acquires a new quality as a dynamically stable cambial system.     

First appearance and distribution of calretinin-immunoreactive neurons in the early development of the chick central nervous system

Silver impregnation studies in chick embryos have shown that, by the 2nd day of incubation, the earliest neurofibrillar differentiation occurred in neuroblasts located at the diencephalic-mesencephalic junction and in the rhombencephalon; some of these neuroblasts were believed to become reticular neurons. Since calretinin, a cytosolic calcium-binding protein of the "E-F hand" family, occurs in reticular neurons, the present study investigated immunohistochemically whether the early differentiating reticular neurons are also the first neurons to express this marker during chick embryo development. The first calretinin-immunoreactive neuroblasts appeared at stage 11 (40-45 h of incubation according to the series of Hamburger and Hamilton), and were located in the basal plate of the diencephalic-mesencephalic junction and of rhombomeres adjacent to the otic placode and in the alar plate and intermediate zone of the cervical spinal cord. In bromodeoxyuridine-injected embryos, these earliest calretinin-immunoreactive neurons were shown to express the calcium-binding protein 11-16 h after their last mitosis. By stage 11 up to the 14th day of incubation (stage 40), the calretinin-immunostained neurons increased in number and ultimately formed a chemically defined subset of neurons belonging to the tegmental reticular formation and raphe region of the brainstem. In the meantime, early calretinin-immunostained nerve processes were shown to form two conspicuous longitudinal bundles which run in the ventral and lateral margins of the brainstem and spinal cord.     

Development of substance P and neurokinin A immunoreactivity in ganglia supplying nerves to the submandibular glands of the rat

Developing submandibular, trigeminal and superior cervical ganglia, which provide innervation to the submandibular glands, were studied for substance P (SP)-and neurokinin A (NKA)-immunoreactive (IR) ganglion cells and nerve fibres in rat. These ganglia were examined by using an indirect immunofluorescence technique at daily intervals from the 16th day in utero (i.u.) until birth, and subsequently on the 2nd, 5th, 7th, 12th, 16th, 30th, 42nd postnatal day and in the adult (3 months). In the submandibular ganglion SP- and NKA-IR cells and fibres first appeared in considerable numbers on the 19th day i.u. (in one sample out of five on the 18th day i.u.), when more than 90% of the ganglion cells were immunoreactive to SP and NKA. The number stayed at more than 90% to the 7th postnatal day and then slowly decreased to the levels of adult animals (18% SP, 17% NKA). The first SP- and NKA-IR ganglion cells and fibres appeared in the trigeminal ganglion on the 18th day i.u. when they represented 7% (SP) and 4% (NKA) of the ganglion cells. The number of SP- and NKA-IR cells increased steadily, reaching a maximum at the time of birth when 68% (SP) and 74% (NKA) of the ganglion cells were immunoreactive. Thereafter they began to decrease toward the level of an adult rat (10% SP, 11% NKA). In the superior cervical ganglion only a few SP-and NKA-IR ganglion cells were detected from the 19th day i.u. to the fifth postnatal day. Positive ganglion cells were also occasionally found in the nerve trunks outside the superior cervical ganglion. From the seventh day onwards no SP- or NKA-IR ganglion cells were found. SP-and NKA-IR SIF (small intensively fluorescent) cells were detected from the 16th postnatal day onwards.     

The ultrastructure of the neurons of a graft developing in the brain of rats experiencing hypoxia

Fragments of the brain cortex of 17- or 18-day-old rat embryos were allotransplanted into the brain cortex of rats subjected to hypoxia. Four days later the graft consisted of mixed differentiating neuroblasts. By the 100th to 130th day after transplantation the graft contained mature neurons, differentiating neurons and neuroblasts. Hypochromic neurons showing the signs of intracellular reparation were also detected. A well-developed neuropile was localized inside the graft. In contrast to the normal brain, neurons in the graft were not organized in layers.     

The action of the cells of hemopoietic organs in chick embryos on mouse CFUdc and CLFUdc]

The humoral influence of cells of hemopoietic organs of chicken embryos of different terms on the development of the colony and cluster formation of mononuclears of the bone marrow of mice was studied in joint cultivation in two-compartment cylindrical diffuse microchambers. The process of formation of colonies and clusters is inhibited by cells of the yolk sac on the 2nd-4th day of the development, by cells of the liver on the 8th-12th day, of the spleen on the 13th-18th day and of the bone marrow--on the 15th day. The yolk sac cells were found to have most considerable inhibiting influence on proliferation and differentiation of cells on the 2nd day of the development of chicken embryo. The yolk sac cells on the 6th day stimulate the formation of colonies and clusters. The yolk sac, beginning from the 4th day of the development, and the liver release humoral factors promoting the formation of erythroid colonies. The erythroid colonies are formed but when cultivated on the vascular membrane of the chicken embryo; the erythroid colonies are not formed when cultivated in the abdominal cavity of mice. Local erythropoietinoid factors are not synthetized by the spleen and bone marrow cells. A supposition is put forward that a combination of the local inhibiting and erythropoietic effects promotes the erythroid differentiation of cells.     

Zur Chemodifferenzierung des Rückenmarks und der Spinalganglien der Ratte

Zusammenfassung Alkalische Phosphatase, saure Phosphatase, Glukose-6-Phosphatdehydrogenase und NADH-Diaphorase können erstmalig am 13., unspezifische Esterase am 15. Embryonaltag (ET) im Cytoplasma der Neuroblasten des Vorderhorns und der Spinalganglien nachgewiesen werden. Ein Unterschied zwischen zervikalem und lumbalem Teil des Rückenmarks besteht nicht. Während der weiteren Entwicklung breiten sich die Enzymreaktionen in der grauen Substanz nach dorsal aus. Am Ende der Tragzeit entspricht die Verteilung der Fermente der erwachsener Tiere. — Die Azetylcholinesterase reagiert ab 14. ET bis zur Geburt in den Hintersträngen stark positiv und ab 15. ET gleichzeitig in den Vorderhornzellen und Spinalganglien. Nach der Geburt sind die Perikarya der Vorderhornzellen Azetylcholinesterase-frei, dafür reagiert die Zelloberfläche positiv. — Die lysosomale Lokalisation der sauren Phosphatase in den Vorderhornzellen kann sehr früh (15. ET) nachgewiesen werden. Glukose-6-Phosphatdehydrogenase und NADH reagieren in diesen Zellen während der Embryonalzeit diffus. Ab 18. ET reagiert in der grauen Substanz das Scitenhorn bei Nachweis der Glukose-6-Phosphatdehydrogenase und NADH am kräftigsten. — Das Ependym und die Commissura anterior besitzen vom 13. ET bis zur Geburt eine deutliche positive Reaktion für saure Phosphatase, Glukose-6-Phosphatdehydrogenase und NADH. Gliazellen haben während der Embryonalentwicklung keine nachweisbare Enzymaktivität. Diese tritt erstmalig für Glukose-6-Phospahtdehydrogenase und NADH am 1. Lebenstag auf und steigert sich abhängig vom Fortschreiten der Myelinisation. — Die Neurone im Spinalganglion zeigen unterschiedliche Fermentreaktionen, wahrscheinlich als Ausdruck verschiedener Zellaktivität. — Belastung durch Schwimmen zieht keine Veränderungen der Enzymaktivitäten im Rückenmark und Spinalganglion nach sich.

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Chemodifferentiation of the spinal cord and spinal ganglion of the rat

Summary In the cytoplasm of neuroblasts of ventral horn and spinal ganglia alkaline phosphatase, acid phosphatase, glucose-6-phosphate dehydrogenase and NADH diaphorase can be first demonstrated on the 13th embryonic day and non-specific esterase activity on the 15th embryonic day. There are no differences between the cervical and the lumbal spinal cord. During the further development the enzyme activities in the gray matter extend in a dorsal direction. At the end of pregnancy the distribution of enzymes is like that in adult animals. — The acetylcholinesterase reaction is strongly positiv in the posterior column from the 14th embryonic day to birth, and from the 15th embryonic day onward also in the nerve cells of the ventral horn and spinal ganglia. After birth the pericarya of the ventral horn are devoid of acetylcholinesterase. There is, however, a positive reaction on the surface of the cells. — The lyososomal localization of acid phosphatase can be demonstrated on the 15th embryonic day in the nerve cells of ventral horn. Glucose-6-phosphate dehydrogenase and NADH diaphorase exhibit a diffuse reaction in these cells during embryonic life. From the 18th embryonic day onward the lateral horn of the gray matter shows the highest activities of glucose-6-phosphate dehydrogenase and NADH-diaphorase. — In the ependyma and the anterior commissure acid phosphatase, glucose-6-phosphate dehydrogenase and NADH diaphorase can be visualized from the 13th embryonic day to birth. — In glial cells no enzymes can be demonstrated during embryonic life. On the 1st day after birth glucose-6-phosphate dehydrogenase and NADH diaphorase occur. These enzyme activities then increase depending on the degree of myelination. — In the neurons of spinal ganglia the enzyme reactions show marked differences probably indicating functional differences. — Continuous swimming does not lead to demonstrable enzyme changes in spinal cord and spinal ganglia.

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Stipendiat des Deutschen Akademischen Austauschdienstes.     

Substance P and calbindin D-28k-immunoreactivity in primary sensory neurons of chick embryos: differential neuronal birthdates and transient co-localization.

During the ontogenesis of dorsal root ganglia (DRG), the immunoreactivity to substance P (SP) and calbindin D-28k (CaBP) appears in chickens at embryonic day 5 (E5) and E10 respectively. To establish the birthdates of primary sensory neurons expressing SP or CaBP, chick embryos were given repetitive intra-amniotic injections of [3H]-thymidine. The neuroblasts giving rise to SP-expressing neurons were labeled up to E6 while those generating CaBP-immunoreactive neurons stopped to incorporate [3H]-thymidine before E5.5. This finding indicates that neurons exhibiting distinct phenotypes may originate from neuroblasts which arrest to proliferate at close but distinct stages of development. To determine whether SP and CaBP are co-expressed or not in DRG neurons, chick embryos at E12, E18, and chickens two weeks after hatching were perfused and fixed to detect simultaneously SP- and CaBP-immunoreactivity in DRG sections. The results showed that SP and CaBP were transiently co-expressed by a subset of neurons at E12. Later, however, the SP-immunoreactivity was gradually lost by these ganglion cells, so that the SP- and CaBP-immunoreaction defined two distinct neuronal subpopulations after hatching. In conclusion, most CaBP-immunoreactive DRG cells derive from a subset of neurons in which SP and CaBP are transiently co-localized.     

Chondrogenic and gliogenic subpopulations of neural crest play distinct roles during the assembly of epibranchial ganglia

In vertebrates, the sensory neurons of the epibranchial (EB) ganglia transmit somatosensory signals from the periphery to the CNS. These ganglia are formed during embryogenesis by the convergence and condensation of two distinct populations of precursors: placode-derived neuroblasts and neural crest- (NC) derived glial precursors. In addition to the gliogenic crest, chondrogenic NC migrates into the pharyngeal arches, which lie in close proximity to the EB placodes and ganglia. Here, we examine the respective roles of these two distinct NC-derived populations during development of the EB ganglia using zebrafish morphant and mutants that lack one or both of these NC populations. Our analyses of mutant and morphant zebrafish that exhibit deficiencies in chondrogenic NC at early stages reveal a distinct requirement for this NC subpopulation during early EB ganglion assembly and segmentation. Furthermore, restoration of wildtype chondrogenic NC in one of these mutants, prdm1a, is sufficient to restore ganglion formation, indicating a specific requirement of the chondrogenic NC for EB ganglia assembly. By contrast, analysis of the sox10 mutant, which lacks gliogenic NC, reveals that the initial assembly of ganglia is not affected. However, during later stages of development, EB ganglia are dispersed in the sox10 mutant, suggesting that glia are required to maintain normal EB ganglion morphology. These results highlight novel roles for two subpopulations of NC cells in the formation and maintenance of EB ganglia: chondrogenic NC promotes the early-stage formation of the developing EB ganglia while glial NC is required for the late-stage maintenance of ganglion morphology.     

Differentiation of postmitotic neuroblasts into substance P-immunoreactive sensory neurons in dissociated cultures of chick dorsal root ganglion

Counts performed on dissociated cell cultures of E10 chick embryo dorsal root ganglia (DRG) showed after 4-6 days of culture a pronounced decline of the neuronal population in neuron-enriched cultures and a net gain in the number of ganglion cells in mixed DRG cell cultures (containing both neurons and nonneuronal cells). In the latter case, the increase in the number of neurons was found to depend on NGF and to average 119% in defined medium or 129% in horse serum-supplemented medium after 6 days of culture. The lack of [3H]thymidine incorporation into the neuronal population indicated that the newly formed ganglion cells were not generated by proliferation. On the contrary, the differentiation of postmitotic neuroblasts present in the nonneuronal cell compartment was supported by sequential microphotographs of selected fields taken every hour for 48-55 hr after 3 days of culture. Apparently nonneuronal flat dark cells exhibited morphological changes and gradually evolved into neuronal ovoid and refringent cell bodies with expanding neurites. The ultrastructural organization of these evolving cells corresponded to that of primitive or intermediate neuroblasts. The neuronal nature of these rounding up cell bodies was indeed confirmed by the progressive expression of various neuronal cell markers (150 and 200-kDa neurofilament triplets, neuron specific enolase, and D2/N-CAM). Besides a constant lack of immunoreactivity for tyrosine hydroxylase, somatostatin, parvalbumin, and calbindin-D 28K and a lack of cytoenzymatic activity for carbonic anhydrase, all the newly produced neurons expressed three main phenotypic characteristics: a small cell body, a strong immunoreactivity to MAG, and substance P. Hence, ganglion cells newly differentiated in culture would meet characteristics ascribed to small B sensory neurons and more specifically to a subpopulation of ganglion cells containing substance P-immunoreactive material.     

Ultrastructure of interneuronal connections in the superior cervical sympathetic ganglion in cats

The structure of interneuronal synapses in the superior cervical sympathetic ganglion was studied in cats under normal conditions and after division of the cervical sympathetic nerves and removal of spinal ganglia T₁₂–L₂. A definite number of dendro-dendritic and dendro-somatic junctions is observed in the ganglion and most of them remained intact after operations of both types; they are probably synapses formed by dendrites of neurons located in the ganglion. Synapses of this sort participate in the formation of nest-like complexes, consisting of consecutive junctions of one neuron with several dendrites. The formation of such complexes may provide the anatomical basis for synchronization of rhythmic neuronal activity in the cellular glomeruli of the ganglion. The results of an ultrastructural study of dendro-dendritic junctions suggests that they are synaptic in nature. Some dendro-dendritic junctions underwent degeneration after both types of operation and are probably endings of neurons in spinal ganglia. Wide club-like structures, probably receptor endings, formed by dendrites of afferent neurons of spinal ganglia, also are found in the ganglion. These structures lie freely in the stoma of the ganglion or form contacts with axon terminals and dendrites of neurons located in the ganglion; some of them degenerate after removal of spinal ganglia T₁₂–L₂.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 13, No. 3, pp. 299–306, May–June, 1981.     

Neural substrate and allatostatin-like innervation of the gut of Locusta migratoria

Allatostatin-like immunoreactivity (ALI) is widely distributed in processes and varicosities on the fore-, mid-, and hindgut of the locust, and within midgut open-type endocrine-like cells. ALI is also observed in cells and processes in all ganglia of the central nervous system (CNS) and the stomatogastric nervous system (SNS). Ventral unpaired median neurons (VUMs) contained ALI within abdominal ganglia IV-VII. Neurobiotin retrograde fills of the branches of the 11th sternal nerve that innervate the hindgut revealed 2-4 VUMs in abdominal ganglia IV-VIIth, which also contain ALI. The VIIIth abdominal ganglion contained three ventral medial groups of neurons that filled with neurobiotin and contained ALI. The co-localization of ALI in the identified neurons suggests that these cells are the source of ALI on the hindgut. A retrograde fill of the nerves of the ingluvial ganglia that innervate the foregut revealed numerous neurons within the frontal ganglion and an extensive neuropile in the hypocerebral ganglion, but there seems to be no apparent co-localization of neurobiotin and ALI in these neurons, indicating the source of ALI on the foregut comes via the brain, through the SNS.     

Intramural neurons in the urinary bladder of the guinea-pig

Summary The urinary bladder of adult female guinea-pigs was stained histochemically to detect the presence of intramural ganglion neurons. Counts on wholemount preparations of entire bladders revealed the presence of 2000–2500 neurons per bladder, either as individual nerve cells or, more often, as ganglia containing up to 40 neurons. Both ganglia and single neurons lie along nerve trunks and are interconnected to form a plexus. Ganglia occur in every part of the bladder; they are more numerous on the dorsal than on the ventral wall, and they are especially abundant in an area within a radius of 800 m from the point of entry into the bladder wall of ureters and urinary arteries. The ganglia are located inside the muscle coat and close to muscle bundles; they usually lie nearer the mucosa than the serosa. Ultrastructurally, each ganglion is surrounded by a capsule; in addition to neurons and glial cells, the ganglia contain capillaries, collagen fibrils and fibroblasts; ganglion neurons are individually wrapped by glial cells and are separated from one another by connective tissue.