Horseradish Peroxidase Reaction Product Research Articles

The Microcomputer-based Color Image Analyzer and Its Application to Histochemistry 1.

For quantification of histochemical reactions, color image analysis, as well as cytophotometry, is important. However, the extremely large amount of information, usually more than one million bits per image, involved in one microscopic picture of a colored histochemical specimen, when digitalized, has inhibited attempts to develop a more convenient system of color image analysis. Recent advances in microcomputer technology have now made it possible to build, at a reasonable cost, an intelligent color terminal equipped with array-processing hardware, a sufficiently large video random-access memory to represent 4096 colors in each pixel, and packages of machine language subroutines called "macro-commands" in the form of read-only memory that can process color images within a few seconds. This intelligent terminal can easily be controlled by a small personal computer via an IEEE-488 interface bus. The digitalized color image can be stored in and retrieved from a floppy disk. As the macro-commands in this system are controlled by BASIC program through CALLS with parameters, it is highly flexible and adapts readily to the varied needs of histochemists. Reported on herein will be the instrumentation of the microcomputer-based color image analyzer and a few examples of applications of this system to histochemistry: color intensification of cytochemical reactions, quantification of enzyme (e.g., horseradish peroxidase) reaction products, periodicacid-Schiff staining, collagen fibers visualized by Azan-Mallory stain, etc. Possible future applications of this color image analyzer will also be discussed.

Immunoperoxidase labeling of Streptococcus mutans for scanning electron microscopy.

The application of an immunoperoxidase method to labeling of Streptococcus mutans subsp. sobrinus for scanning electron microscopy is described. Bacteria from four separate cultures were fixed in 2.5% buffered glutaraldehyde solution. The specimens were treated in accordance with an indirect immunolabeling procedure using a rabbit anti-S. mutans subsp. sobrinus gamma-globulin. Labeled bacteria were equipped with a layer of small, distinct globules of horse-radish peroxidase reaction product. Bacteria exposed to control incubations were not equipped with this layer.

The survival of neonatal rat retinal ganglion cells in vitro is enhanced in the presence of appropriate parts of the brain.

The enzyme horseradish peroxidase (HRP) was injected into the visual centres of the brains of neonatal rats. Following dissociation of retinae into tissue culture, the ganglion cells could be identified by appropriate histochemical staining for HRP reaction product. Cultures were prepared of dissociated retinae from rats aged 2-6 days postnatal. After 3 h the cultures were fixed, and HRP-labelled cells visualized and counted. Estimates were made of the number of ganglion cells per retina at each age. Results indicated a loss of ganglion cells during the first few postnatal days. This loss paralleled that observed in vivo. It was further found the retinal ganglion cells died rapidly in vitro when cultured in a minimal medium. Only 50% of ganglion cells originally plated remained viable after 24 h. However, the survival rate could be increased to 100% by co-culturing the cells with diencephalon and mesencephalon; these contain the retinorecipient nuclei. Co-culturing with cerebellum did not result in such an enhanced survival rate. Ganglion cells could be maintained over longer periods of time by reinoculating the cultures with additional tissue containing diencephalon and mesencephalon. These results support the hypothesis that developing neurons require trophic factors from their target tissues in order to survive.

The nuclei of origin of brain stem enkephalin and substance P projections to the rodent nucleus raphe magnus

The sites of origin of brain stem enkephalin and substance P projections to the rodent nucleus raphe magnus were studied utilizing the combined horseradish peroxidase retrograde transport-peroxidase-antiperoxidase immunohistochemical technique. Several brain stem areas were found to contain both enkephalin- and substance P-like immunoreactive double labeled neurons following injection of horseradish peroxidase into the raphe magnus. Nuclei providing both enkephalin and substance P inputs to the raphe magnus include the nucleus reticularis paragigantocellularis, the nucleus cuneiformis, the nucleus solitarius and the trigeminal subdivision of the lateral reticular nucleus. Enkephalin projections to the raphe magnus were also found to originate from the dorsal parabrachial nucleus, the nucleus reticularis gigantocellularis pars α and from an area which corresponds to the A5 group of Dahlström & Fuxe. Additional neurons containing substance P-like immunoreactivity and horseradish peroxidase reaction product were identified in the superior central raphe nucleus and the nucleus pontis oralis. The midbrain periaqueductal gray contributes very few enkephalin and substance P fibers to the raphe magnus. The nucleus raphe magnus is a key structure in the intrinsic analgesia system and it has also been implicated in other diverse and non-nonciceptive functions. The present study identifies several brain stem sites which provide enkephalin and substance P input to this raphe nucleus. Several of these nuclei have been implicated in central analgesic mechanisms or in non-nociceptive autonomic functions. The present investigation raises the possibility that these brain stem regions may modulate neuronal activity in the raphe magnus via enkephalin or substance P projections and thus influence the involvement of the raphe magnus in both opiate related mechanisms of pain control and non-nociceptive functions.

In vitro complement binding on cytoplasmic structures in normal human skin: immunoelectronmicroscopic studies.

We have previously provided evidence that suggests that exposure of cryostat skin sections to normal human serum (NHS) results in the antibody-independent Clq binding to cytoplasmic structures of various cell types, leading to classical complement pathway activation as evidenced by cytoplasmic C3 deposition. In the present study, we have employed immunoelectronmicroscopic methods to clarify the exact nature of cytoplasmic C3 binding structures. Incubation of cryostat skin sections with NHS followed by peroxidase-labeled rabbit anti-human C3 serum (HRP-R/Hu C3) revealed that intracytoplasmic binding of C3 occurred in suprabasal keratinocytes, melanocytes, fibroblasts, smooth muscle cells, endothelial cells, pericytes, Schwann cells, and nerve axons, but not in basal keratinocytes, Langerhans cells, and other cellular constituents of the skin. C3 binding, as revealed by the deposition of HRP reaction product, was exclusively confined to intermediate-sized filaments (ISF), which can therefore be considered to represent the subcellular site for classical complement pathway activation. Under experimental conditions that do not allow classical complement pathway activation, ISF were not decorated. Our observation that ISF of ontogenetically different cell types share the capacity of complement fixation is in accordance with the recent finding that different ISF types, despite their biochemical and antigenic heterogeneity, have common alpha-helical domains and may provide a clue to the mechanism and site of interaction between complement components and ISF.

Disruption of iridial blood-aqueous barrier in experimental diabetic rats.

The permeability pattern of iridial blood-aqueous barrier in streptozotocin-diabetic rats, maintained for 1-6 months, was studied with the light and electron microscopes, using horseradish peroxidase as a tracer. A reaction product of horseradish peroxidase was confined to the vascular lumina and to a small number of vesicles on the luminal portion of the endothelial cells in control rats and diabetic rats maintained for 1 month. In diabetic rats maintained for 2-6 months, endothelial cells contained a large number of horseradish peroxidase-labeled vesicles which opened into the basement membrane, and intercellular junctions of the endothelial cells were filled with horseradish peroxidase. Horseradish peroxidase was consistently found in the stroma around the vessels, and seemed to reach the anterior chamber through the intercellular spaces between the fibroblasts. However, the passage of horseradish peroxidase was blocked by the posterior epithelial cells.

Endocytic pathways at the lateral and basal cell surfaces of exocrine acinar cells.

In parotid acinar cells, horseradish peroxidase (HRP) administered via the main excretory duct is endocytosed from the apical cell surface in smooth C- or ring-shaped vesicles (Oliver, C. and A. R. Hand. 1979. J. Cell Biol. 76:207). These vesicles ultimately fuse with lysosomes adjacent to the Golgi apparatus. The present investigation extends these findings and examines the uptake and fate of intravenously injected HRP from the lateral and basal cell surfaces of resting and stimulated parotid and pancreatic acinar cells from rats and mice. Isoproterenol and pilocarpine were used to stimulate the parotid gland and the pancreas, respectively. HRP was internalized in smooth and coated vesicles primarily in areas of membrane infoldings. Both the number of coated vesicles and the amount of tracer internalized increased markedly following secretagogue administration. In both resting and stimulated cells, the HRP was rapidly sequestered in a unique system of basally located lysosomes that possess trimetaphosphatase activity, but not acid phosphatase activity. At 1-3 h after HRP administration, reaction product was also found in multivesicular bodies, vesicles, and lysosomes adjacent to the Golgi apparatus. With time, more HRP was localized in Golgi-associated lysosomes. By 6-7 h, tubules in the apical cytoplasm of stimulated cells contained HRP reaction product. When native ferritin was administered retrogradely and HRP injected intravenously, both tracers could be localized in the same lysosome after 4-5 h, indicating that material taken in from all cell surfaces mixes in Golgi-associated lysosomes. The results of this study suggest that two separate and distinct endocytic pathways exist in exocrine acinar cells: one involves membrane retrieval from the apical cell surface; and the other is a stimulation-dependent process at the lateral and basal cell surfaces.

Uptake and transport of horseradish peroxidase by cochlear spiral ganglion neurons.

Cochlear spiral ganglion neurons in the cat have been classified as type I and type II. The type II neurons are of special interest since they are reported to provide the afferent innervation to three-quarters of the cochlear hair cells, and also because of a recent assertion that they do not project to the brain. In the present study the neuronal marker horseradish peroxidase (HRP) was utilized to re-examine these issues. HRP was injected into the intranuclear cochlear nerve root of adult cats. 18 to 48 h post-injection HRP reaction product was observed in both type I and type II neurons. The majority of labeled cells were characterized by granular reaction product, while a smaller number of cells were also diffusely filled with HRP, resulting in intense staining of the cell soma and its processes. These data indicate that the central axons of type II neurons are constituents of the cochlear nerve root at the level of the brainstem and thus do project centrally. In the organ of Corti HRP-filled fibers to both inner and outer hair cells were observed and demonstrated in electron microscopy to be afferent neurons. This intra-axonal accumulation of the HRP by outer hair cell afferents constitutes direct evidence of the functional projection of these neurons to the cochlear nucleus.

Ultrastructure of hair follicle afferent fibre terminations in the spinal cord of the cat.

In acute electrophysiological experiments on anaesthetized cats, single identified hair follicle afferent fibres were injected with horseradish peroxidase (HRP). The HRP was injected from an intra-axonal microelectrode in the lumbosacral spinal cord. One to six hours after injection the animals were perfused and the tissue prepared for light and electron microscopy (EM). Axon collateral arborizations containing HRP reaction product were identified in thick sections under the light microscope and the same tissue then cut on the ultramicrotome for EM study. The terminal branches of the collaterals kept their myelin sheaths until they were 0.45-1.0 micron in diameter, just before they formed synaptic boutons. Synaptic boutons (1.0-4.0 microns in diameter) were usually of the en passant variety and made contact with dendrites. The contacts were asymmetrical (Type I) and contained round, clear synaptic vesicles of 35-60 nm diameter. Both the non-myelinated portion of the terminal axon and the synaptic boutons received axo-axonic contacts. These axo-axonic boutons contained clear (agranular) vesicles irregular in profile.

Organization of nucleus rotundus, a tectofugal thalamic nucleus in turtles. II. Ultrastructural analyses.

Nucleus rotundus in a large, tectorecipient nucleus in the dorsal thalamus of the pond turtles Pseudemys scripta and Chrysemys picta. Rotundal neurons form a single, morphologically homogeneous population (Rainey, '79) that projects to the dorsal ventricular ridge in the telencephalon. The present paper examines the morphology of and the distribution of synapses upon rotundal neurons. Astrocytes, oligodendrocytes, and neurons can be identified in both 1-micrometer sections stained with toluidine blue and electron micrographs of nucleus rotundus. Rotundal neurons contain euchromatic nuclei and the usual complement of mitochondria, rough endoplasmic reticulum, and free ribosomes in their cytoplasm. They are morphologically homogeneous. Two types of terminal boutons can be defined in rotundus. RA boutons contain round synaptic vesicles and form asymmetric synaptic junctions with rotundal dendrites. FS boutons contain small, flattened or pleomorphic vesicles and form nearly symmetric synaptic junctions with rotundal dendrites and somata. RA boutons occasionally form clusters of contiguous boutons that are presynaptic to one or more thin, central profiles. These profiles are probably the dendritic appendages observed on peripheral dendrites in Golgi material. The distribution of RA and FS boutons along dendrites was investigated by a two-step procedure. First, rotundal neurons were retrogradely solid-filled with horseradish peroxidase reaction product. Dendritic diameters were measured at 20 micrometer intervals along dendritic shafts to produce a plot of dendritic diameter as a function of distance from the soma. Second, the percentage of membrane on dendritic profiles of different diameters that was contacted by RA and FS terminals was determined from electron micrographs. Comparison of the two plots indicates that both bouton types are distributed along the full extent of the dendritic tree, but RA boutons are much more common on the distal two-thirds of rotundal dendrites. This analysis suggests that rotundal neurons form a single population of cells that are morphologically homogeneous and project to the forebrain. There is no indication of interaction between neurons in nucleus rotundus, either via axonal collaterals or presynaptic dendrites. Boutons are distributed on rotundal neurons such that FS boutons are prevalent on the somata and most proximal segments of the dendritic shafts, while RA boutons are most common on the more distal dendritic shafts. RA boutons also contribute to synaptic clusters that may center around complex dendritic appendages.

Retinal projections in adult and newborn grey squirrels.

Retinal projections in newborn squirrels were compared to those in adults by using horseradish peroxidase (HRP) as a highly sensitive anterograde tracer. In both newborn and adult squirrels, the HRP reaction product was found in the dorsal lateral geniculate nucleus, the superior colliculus, the pretectal nuclei, and the nuclei of the accessory optic tract. Thus, newborn squirrels have retinal input to most or all structures normally innervated in the adult. However, the pattern of terminations differed in the newborn from that in the adult, and this was especially apparent in the dorsal lateral geniculate nucleus and the superior colliculus. In the dorsal lateral geniculate nucleus, the regions of ipsilateral and contralateral retinal inputs were clearly less segregated than in adults, although the adult laminar pattern of retinal terminations was partially apparent, even though there was yet no cytoarchitectural evidence of the adult lamination pattern. In the superior colliculus, a marked difference was seen in the pattern of ipsilateral retinal terminations. In the adult, ipsilateral retinotectal input was restricted to a narrow, dense, patchy, mediolateral band in stratum opticum in the rostral colliculus. In the newborn, the ipsilateral retinotectal input was less dense, free of patches, spread in thickness to include much of the stratum opticum and the superficial grey, and spread in extent to include all but the caudal pole of the colliculus. These observations are consistent with the prevailing view that visual connections are initially widespread and become restricted during the course of development.

Proteinuria and structural alterations in rat glomerular basement membranes induced by intravenously injected anti-laminin immunoglobulin G.

Antibodies against laminin, which is a defined glycoprotein of basement membranes, were produced in sheep and affinity purified by immunoadsorption on laminin-Sepharose (S alpha L). When injected intravenously into rats, S alpha L rapidly bound in a linear pattern to the glomerular basement membrane (GBM) in the peripheral and mesangial regions of all glomeruli, and, when greater than 0.5 mg S alpha L was injected, to some tubular BM as well. 1-2 h after the injection of conjugates of horseradish peroxidase (HRP) and S alpha L, HRP reaction product was present throughout the full thickness of the GBM and mesangial matrix. [125I]S alpha L binding to the kidney in vivo increased linearly over the dose range of 40-950 micrograms of IgG and accounted for approximately 2% of the injected dose/g kidney. When 4 mg of [125I]S alpha L was injected, 1.5% or 62 micrograms/g kidney was bound. Proteinuria did not develop within 7 wk of injection in rats that received 0.5-1.6 mg of S alpha L. In contrast, all animals that received injections of 4 mg of S alpha L gradually became proteinuric within 3-6 wk. Thickening, reduplication, and flocculent subendothelial deposits were observed in the GBM of these animals. In addition, mononuclear cells adhered to the GBM and infiltrated beneath the endothelium. However, the deposition of rat C3 was infrequently observed, and rat IgG was not seen in the glomeruli of any rat that received S alpha L. 10 wk after injection, much greater amounts of S alpha L appeared within the mesangium than the peripheral GBM. These results demonstrate that the interaction of S alpha L with the GBM, possibly in concert with infiltrating mononuclear cells, gradually altered the structure and permeability characteristics of the glomerulus independent of a host anti-S alpha L humoral response.

Retrograde axonal transport of a wheat germ agglutinin-horseradish peroxidase conjugate in aplysia californica

To begin examining retrograde transport in a single invertebrate neuron we have used wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP). 18 h after the conjugate was injected extracellularly into the neuropil of the buccal ganglion of Aplysia, HRP reaction product could be detected cytochemically in putative lysosomes, cisternae and vesicles near Golgi in the giant metacerebral neuron (GCN) of the cerebral ganglion. Appearance of reaction product in the cell body was blocked by ligating GCN's axon and was inhibited by colchicine.

Uptake of horseradish peroxidase at isolated nerve terminals in relationship to transmitter release; Biochemical results

The uptake of horseradish peroxidase (HRP) into isolated nerve terminals (synaptosomes) has been studied by using a spectrophotometric method to determine the enzyme activity. HRP is rapidly taken up by synaptosomes, it is not removed by multiple washes in iso-osmotic medium but is lost if the particles are ruptured by hypo-osmotic conditions. The uptake is not affected by metabolic poisons, is reduced at lower temperature and is not with any significant release of cytoplasmic lactate dehydrogenase suggesting an endocytotic mechanism. Intra-synaptosomal HRP can be released by a process that is similar to uptake and also not accompanied by any loss of synaptosomal lactate dehydrogenase exocytosis. Depolarization of synaptosomes (by high potassium concentrations) was found to release [ 14C]ACh but to have no effect on HRP uptake either simultaneouly or after recovery in an non-depolarizing medium. Absence of Ca 2+ prevented depolarization evoked release of [ 14C]ACh but had no effect on the uptake of HRP. The release of HRP was not increased by depolarization even though [ 14C]choline taken up during the same period wasreleased as [ 14C]ACh. It is concluded that the endo-exocytotic cycle that transport HRP across the synaptosomal membrane is unrelated to tranmitter release. A discrete vesicular localization of HRP reaction product was only occasionally in the EM nor could consistent differences resulting from depolarization be observed. However, nthe untrastructural localization was found to be unreliable because glutaradehyde fixation irreversiy inactivated 80–90% of the HRP even when it was sequestered within synaptosomes and the insoluble reaction product precipitated from a supersaturated solution onto membranes.

Cerebellar afferents to paramedian lobule from the trigeminal complex in Tupaia glis: a horseradish peroxidase (HRP) study.

Projections from the trigeminal complex to paramedian lobule (PML) were studied in the tree shrew (Tupaia glis) by means of retrograde transport of horseradish peroxidase (HRP). Neurons which project to both dorsal and ventral folia of PML are located primarily in those areas of the trigeminal nuclear complex interpreted as nucleus interpolaris (Vi) and caudal areas of the nucleus oralis (Vo). The majority of HRP-labeled neurons lie in ventral and ventrolateral regions of Vi/Vo. No HRP-reactive cells are present in the principal (Vp), mesencephalic, or motor nuclei nor in nucleus caudalis or rostral portions of oralis. The majority of trigeminocerebellar (TC) cells are found in ipsilateral Vi; however, sparse numbers of labeled somata are present in this subnucleus on the contralateral side. Within Vi/Vo, small fusiform and medium-and large-sized multipolar neurons contain HRP-reaction product. Large multipolar cells are found primarily in ventrolateral portions of Vi/Vo, while medium and small neurons are scattered throughout the ventral half of the nucleus. Small-sized neurons are also present dorsally within Vi/Vo. Axons of labeled TC cells course laterally through the spinal trigeminal tract, enter medial aspects of the restiform body, and arch dorsally into the cerebellum.

The loss of ganglion cells in the developing retina of the rat

Horseradish peroxidase (HRP) was injected into both sides of the brain of newborn and adult rats. The number of retinal ganglion cells was estimated by counting cells containing granules of HRP reaction product. The mean number of labelled cells in 2-day-old animals was 169,500 (S.D. ± 16,000, n = 6). By the tenth postnatal day the mean number of labelled cells had fallen to 113,500 (± 2900, n = 3). This value is similar to the mean number of labelled cells in the adult animal (113,000 ± 2700; n = 4). Thus, during the first few postnatal days the number of retinal cells projecting to the central visual nuclei is reduced by at least 35%.

The ultrastructural identification of vagal terminals in the solitary nucleus of the cat after anterograde labelling with horseradish peroxidase

Horseradish peroxidase (HRP) was injected into the nodose ganglion of the cat in order to label the axon terminals of vagal afferent fibres in the solitary nucleus. HRP reaction product was seen in axons, the majority of which were unmyelinated. Axon terminals containing round clear vesicles and an occasional dense-core vesicle were also labelled. These terminals synapsed upon both large and small dendritic elements, the majority of which were less than 1.0 μm in diameter. This labelling method appears not to affect adversely the normal ultrastructural characteristics of terminals or their postsynaptic relationships and in these respects is superior to electron microscopic degeneration methods.

Cholinergic neurons in the basal forebrain of the cat have direct projections to the sensorimotor cortex

Previous studies showed that projections from the cells in the substantia innominata to the sensorimotor cortex exist in the monkey and rat and that this group of cortical afferent fibers utilizes acetylcholine as a neurotransmitter. Because similar studies have not been made in the cat, the following study was undertaken to analyze the extent and distribution of this projection from the basal forebrain. Horseradish peroxidase (HRP) injections were made into the anterior and posterior sigmoid gyri 24 h before, and diisopropyl fluorophosphate was injected intramuscularly 3 h before the anesthetized cats were perfused. Brain sections from these cats were incubated in solutions to simultaneously detect retrogradely transported HRP and acetylcholinesterase (AChE) reaction product within the somata. The cell bodies that contained reaction product for both HRP and AChE were mostly large (25 to 30 μm) and multipolar. These double-labeled cells were located in (i) the nucleus of the diagonal band in rostral sections, (ii) the globus pallidus, entopeduncular nucleus, and substantia innominata at the level of the anterior commissure, and (iii) the lateral hypothalamus in the most caudal sections. Many of these sites corresponded to that for the basal nucleus of Meynert, an aggregation of large multipolar neurons scattered throughout the basal forebrain. Although the presence of AChE within a cell does not define a cholinergic neuron, recent studies indicated that its presence is a requirement for this neurotransmitter. These data together with biochemical and immunocytochemical data indicate that a cholinergic projection to the sensorimotor cortex of cats arises from the basal forebrain. This pathway may play a vital role in memory and cognition.

Localization of synaptic and nonsynaptic nicotinic-acetylcholine receptors in the goldfish retina.

The localization of nicotinic-cholinergic receptors in the inner plexiform layer (IPL) of goldfish retina was studied by electron microscopic analysis of the binding pattern of a conjugate or horseradish peroxidase and alpha bungarotoxin (HRP-alpha BTx). Specific HRP reaction product (blockade by 1mM curare) was found at both synaptic and nonsynaptic sites. Synaptic binding sites for HRP-alpha BTx, which accounted for only 16% of the total specific reaction product sites, always involved an amacrine process as the presynaptic element, whereas amacrine, ganglion, and bipolar cells could be post-synaptic elements at labeled synapses. Only 17.5% of the total number of amacrine synapses were labeled by HRP-alpha BTx. Labeled synapses showed the same distribution in the IPL as unlabeled synapses: bimodal for amacrine-to-bipolar synapses with peak concentrations at the 20% and 80% layers and unimodal for amacrine-to-nonbipolar synapses with a peak concentration at the 60% layer. Nonsynaptic binding sites for HRP-alpha BTx (84% of total) were seen on the dendrites of ganglion, amacrine, and bipolar cells. The distribution of the nonsynaptic sites in the IPL largely accounts for the trilaminar binding pattern of 125I-alpha BTx as observed in light microscopic autoradiographs. If, as appears likely, the distribution of synapses is the relevant variable in determining the sites of neuronal interaction for a given transmitter system, then this study further illustrates the importance of distinguishing synaptic from nonsynaptic binding when using receptor-ligand probes to localize sites of chemical synaptic transmission.

Electron Microscopic Study of Retrograde Axonal Transport of Horseradish Peroxidase in the Wall of the Small Intestine in the Cat

The intracellular distribution of horseradish peroxidase (HRP) transported intra-axonally from the mesenteric nerve to the wall of the small intestine has been examined electron microscopically. After 2 days, some of the neurons of the myenteric and submucosal plexuses showed an accumulation of HRP. The HRP reaction product consisted of fine, discrete cytoplasmic granules and it was located in lysosome-like dense bodies with a 400-500 nm of diameter. The morphological features of the labelled neurons, with synapses occurring on their surfaces, were apparently different from those of unlabelled neurons. Some nerve fibers were also labelled and could be found in all layers of the small intestine. The labelled neurons project directly towards the celiac ganglia, and due to the synapses on their surfaces, it is supposed that these neurons collect information from other local nerve cells and centripetally convey them to the prevertebral ganglia.