Sacral Dorsal Root Ganglia Research Articles

Analysis of latency in cattle after inoculation with a temperature sensitive mutant of bovine herpevirus 1 (RLB106)

Calves were inoculated with the bovine herpes virus 1 (BHV-1) vaccine strain (RLB 106), which is a temperature sensitive mutant. The route of inoculation was intranasal instillation or intramuscular (IM) injection (flank or neck). As a control, five calves were given placebo by IM injection of the neck. Regardless of the infection route, clinical symptoms did not occur. However, BHV-1 neutralizing antibodies were detected after inoculation demonstrating that sero-conversion occurred. At 60 days post-inoculation, dexamethasone was given by IM injection to attempt reactivation of RLB 106. Only those calves inoculated by the intranasal route shed virus leading to an increase in BHV-1 specific antibodies. As expected, viral DNA and the latency related-RNA were detected in trigeminal ganglia (TG) of calves inoculated by the intranasal route. In contrast, viral nucleic acid was not detected in TG of calves inoculated by the IM route or in calves inoculated with placebo. In cervical ganglia or sacral dorsal root ganglia, viral nucleic acid was not consistently detected. This study provides evidence that efficient latency and reactivation does not occur following IM inoculation. Since serum-neutralizing antibodies were detected in all inoculated calves, IM inoculation led to sero-conversion.

Glutamate and aspartate immunoreactivity in dorsal root ganglion cells supplying visceral and somatic targets and evidence for peripheral axonal transport

Glutamate (Glu) is released by primary sensory neurons at their central synapses, although immunohistochemical studies have shown that only a proportion of these cell bodies are Glu-immunoreactive. Antisera raised against Glu or aspartate (Asp) were used to investigate whether neurons that store high levels of these substances have a unique neuropeptide content or target projection. In male rats, many lumbar and sacral dorsal root ganglion cells and their associated glia show high levels of Glu or Asp immunoreactivity, and fewer than half of these also express substance P or calcitonin gene-related peptide. Conversely, only a minority of peptide-containing neurons store high levels of excitatory amino acids. When neurons that were labelled retrogradely from somatic (skin, gastrocnemius muscle) or visceral (bladder, rectum) targets were immunostained for peptides or amino acids, there was some variation in the peptide expression of their sensory nerve supply, but there was very little or no difference in the prevalence of Glu- or Asp-immunoreactive neurons. In vitro studies on isolated lumbar dorsal root ganglia showed that, after crushing nerve roots, Glu and Asp were transported in both central and peripheral directions, similar to substance P. These studies showed that primary afferent neurons store different levels of Glu and Asp in their somata but that this is not correlated with their target tissue or peptide content. This suggests that both visceral and somatic sensory neurons may vary considerably in the way they release, store, or metabolise amino acids. Peripheral and central transport of amino acids suggests that, in some neurons, reuptake at the synapse may need to be supplemented by amino acids that are produced or accumulated in the soma.

Degenerative changes of afferent neurons in the lumbar sacral dorsal root ganglia following complete urethral obstruction in guinea pigs

Correspondence to Mr Christopher R. Chapple, Urology Research Department, Royal Hallamshire Hospital, Glossop Road, Sheffield S10 2JF, UK. Tel: +44 114 271 2791; fax: +44 114 279 8318 Royal Hallamshire Hospital, Sheffield, UK

Morphometric evaluation of the sacral dorsal root ganglia: A cadaveric study

An anatomic study of the sacral dorsal root ganglia (DRG) was performed to determine the location and dimensions of the S1-4 DRGs and to correlate this information to sacral nerve root ganglion lesions. S1 DRGs were located in the intraforaminal region in 55-60% and in the intracanalar region in 40-45%. S2 DRGs were in the intraforaminal region in 15-50% and in the intracanalar region in 50-85%. All the S3 and S4 DRGs were located in the intracanalar region. None of the sacral DRGs was located in the extraforaminal region. The intraforaminal position of the S1 and S2 ganglia renders them vulnerable to compression caused by sacral fractures involving the sacral foramina because of the little space available for these ganglia in the foraminal region. The S1 DRG, with its its relatively larger dimensions and its intracanalar position relative to the other sacral DRGs, may be susceptible to compression by the L5-S1 disk herniation. Its intraforaminal position may predispose it to injury during S1 or S2 pedicle screw placement.

Morphometric evaluation of the sacral dorsal root ganglia

An anatomic study of the sacral dorsal root ganglia (DRG) was performed to determine the location and dimensions of the S1-4 DRGs and to correlate this information to sacral nerve root ganglion lesions. S1 DRGs were located in the intraforminal region in 55–60% and in the intracanalar region in 40–45%. S2 DRGs were in the intraforaminal region in 15–50% and in the intracanalar region in 50–85%. All the S3 and S4 DRGs were located in the intracanalar region. None of the sacral DRGs was located in the extraforaminal region. The intraforaminal position of the S1 and S2 ganglia renders them vulnerable to compression caused by sacral fractures involving the sacral foramina because of the little space available for these ganglia in the foraminal region. The S1 DRG, with its its relatively larger dimensions and its intracanalar position relative to the other sacral DRGs, may be susceptible to compression by L5-S1 disk herniation. Its intraforaminal position may predispose it to injury during S1 or S2 pedicle screw placement.

Localization of estrogen receptor protein and estrogen receptor messenger RNA in peripheral autonomic and sensory neurons

The presence of estrogen receptor protein and estrogen receptor messenger RNA was revealed in peripheral ganglionic neurons of the rat. The pelvic parasympathetic autonomic ganglion and lumbosacral dorsal root sensory ganglia were examined for estrogen receptor-containing neurons because they have known projections to the uterus and uterine cervix. The vagal nodose ganglia were studied for estrogen receptor-containing neurons because they are suspected sources of influence on the uterus. Immunohistochemistry, in situ hybridization histochemistry and retrograde tracing were utilized. Immunoreactivity for estrogen receptors was evident in the nuclei of a subpopulation of neurons in the pelvic ganglia, sixth lumbar and first sacral dorsal root ganglia and nodose ganglia. Some estrogen receptor-positive neurons also contained the retrograde tracer FluoroGold that previously had been injected into the uterus and uterine cervix. Estrogen receptor messenger RNA was also evident in a subpopulation of ganglionic neurons. These data suggest that a certain population of neurons in autonomic and sensory ganglia are capable of synthesizing estrogen receptors and these receptors can serve as binding sites for estrogen. Thus, certain aspects of the structure, function and neurochemistry of some autonomic and sensory neurons may be influenced by the sex steroid estrogen.

Extrinsic Innervation of the Cat Prostate Gland: A Combined Tracing and Immunohistochemical Study

The purpose of the present study was to determine the peripheral neural pathways, spinal distribution, sizes, and peptide transmitter content of primary afferent and autonomic efferent neurons that innervate the prostate gland. Retrograde transport of the fluorescent dye "fast blue" (injected into the prostate gland) was combined with neurotransmitter immunohistochemistry. Lesions of the pelvic and pudendal nerve were used to determine the peripheral neural pathways. The majority of the afferent innervation arose from the sacral dorsal root ganglia (DRG) and was equally comprised of small, substance P- and calcitonin gene-related peptide-immunoreactive (IR) neurons and large, non-IR neurons. The majority (70%) of the afferent axons traversed the pelvic nerve with the remainder traversing the pudendal nerve. Fewer afferent neurons were located in lumbar DRG; nearly all of these were small, peptidergic neurons. Efferent autonomic neurons were located in the inferior mesenteric ganglia (IMG), sympathetic chain ganglia (SCG), and pelvic plexus ganglia (PPG). Nearly all efferent neurons in the IMG and SCG, but only 2/3 of the PPG neurons, contained dopamine-beta-hydroxylase. Substantial neuropeptide Y innervation was derived from the SCG but not the IMG or PPG. First, clinical reports suggested that sensory innervation of the prostate would be purely nociceptive in nature (implied by small, peptide-IR neurons). However, the present study suggests that there may also be a substantial, presumably non-nociceptive, afferent innervation (implied by findings of large, non-IR neurons). Second, 3 sources of autonomic efferent innervation exist, each being different in the distribution of transmitter phenotypes. Understanding the physiological role of putative non-nociceptive primary afferent neurons, and the differential roles of the various autonomic neurons, is likely to be important in developing therapies for the treatment of prostatic diseases, such as benign prostatic hyperplasia and prostatodynia.

DNA immunization against experimental genital herpes simplex virus infection.

A nucleic acid vaccine, expressing the gene encoding herpes simplex virus (HSV) type 2 glycoprotein D (gD2) under control of the cytomegalovirus immediate-early gene promoter, was used to immunize guinea pigs against genital HSV-2 infection. The vaccine elicited humoral immune responses comparable to those seen after HSV-2 infection. Immunized animals exhibited protection from primary genital HSV-2 disease with little or no development of vesicular skin lesions and significantly reduced HSV-2 replication in the genital tract. After recovery from primary infection, immunized guinea pigs experienced significantly fewer recurrences and had significantly less HSV-2 genomic DNA detected in the sacral dorsal root ganglia compared with control animals. Thus, immunization reduced the burden of latent infection resulting from intravaginal HSV-2 challenge, and a nucleic acid vaccine expressing the HSV-2 gD2 antigen protected guinea pigs against genital herpes, limiting primary infection and reducing the magnitude of latent infection and the frequency of recurrent disease.

Nitric oxide nerves in the uterus are parasympathetic, sensory, and contain neuropeptides

Nitric oxide (NO) is synthesized in neurons and is a potent relaxor of vascular and nonvascular smooth muscle. The uterus contains abundant NO-synthesizing nerves which could be autonomic and/or sensory. This study was undertaken to determine: 1) the source(s) of NO-synthesizing nerves in the rat uterus and 2) what other neuropeptides or transmitter markers might coexist with NO in these nerves. Retrograde axonal tracing, utilizing Fluorogold injected into the uterine cervix, was employed for identifying sources of uterine-projecting neurons. NO-synthesizing nerves were visualized by staining for nicotinamide adenine dinucleotide phosphate (reduced)-diaphorase (NADPH-d) and immunostaining with an antibody against neuronal/type I NO synthase (NOS). NADPH-d-positive perikarya and terminal fibers were NOS-immunoreactive (-I). Some NOS-I/NADPH-d-positive nerves in the uterus are parasympathetic and originate from neurons in the pelvic paracervical ganglia (PG) and some are sensory and originate from neurons in thoracic, lumbar, and sacral dorsal root ganglia. No evidence for NOS-I/NADPH-d-positive sympathetic nerves in the uterus was obtained. Furthermore, double immunostaining revealed that in parasympathetic neurons, NOS-I/NADPH-d-reactivity coexists with vasoactive intestinal polypeptide, neuropeptide Y, and acetylcholinesterase and in sensory nerves, NOS-I/NADPH-d-reactivity coexists with calcitonin gene-related peptide and substance P. In addition, tyrosine hydroxylase(TH)-I neurons of the PG do not contain NOS-I/NADPH-d-reactivity, but some TH-I neurons are apposed by NOS-I varicosities. These results suggest NO-synthesizing nerves in the uterus are autonomic and sensory, and could play significant roles, possibly in conjunction with other putative transmitter agents, in the control of uterine myometrium and vasculature.

Smaller number of large myelinated fibers and focal myelin thickening in mutant quails deficient in neurofilaments.

The peripheral nervous system of a mutant of a Japanese quail deficient in neurofilaments (mutant) and of a normal Japanese quail (control) was morphometrically evaluated to characterize the morphological findings, especially those of the myelinated fibers of the mutant. In the proximal peroneal nerves, the frequency of the teased myelinated fibers showing the focal myelin thickening was higher in mutant than in control (P < 0.001) without obvious ongoing axonal degeneration and segmental demyelination. The total numbers of the myelinated fibers in the proximal and distal peroneal nerve, and in the tibial nerve branch to gastrocnemius muscle (pars medialis) were similar between control and mutant, although the number of the large myelinated fibers was less (P < 0.01) and the number of the small myelinated fibers was greater (P < 0.01) in mutant compared with control. The median diameters of neuronal cell bodies of the sacral dorsal root ganglia were similar in control and mutant. The percentages of light, dark and unclassified cells evaluated based on the histologic cytoplasmic features were also similar in control and mutant. Therefore, morphometric alterations were more pronounced in the peripheral myelinated nerve fibers compared with those in the cell bodies of the spinal dorsal root ganglia. We concluded that a smaller number of large myelinated fibers with a greater number of small myelinated fibers and the presence of focal myelin thickening are the main morphologic findings in this mutant, probably due to the arrest of radial growth or maturation of the axons of the myelinated fibers in the absence of ongoing myelinated fiber degeneration.

A large proportion of afferent neurons innervating the uterine cervix of the cat contain VIP and other neuropeptides

Axonal tracing techniques were used in combination with immunohistochemistry to examine the distribution of neuropeptides in afferent pathways from the uterine cervix of the cat. Primary afferent neurons innervating the uterine cervix were identified by axonal transport of the dye, fast blue, injected into the cervix. Fifteen to twenty-five days after the injection, dorsal root ganglia (L1-S3) were removed and incubated for 48-72 h in culture medium containing colchicine to increase the levels of peptides. Calcitonin gene-related peptide (CGRP), cholecystokinin (CCK), leucine-enkephalin (LENK), somatostatin, substance P and vasoactive intenstinal polypeptide (VIP) were identified by use of indirect immunohistochemical techniques. Eighty-four percent of uterine cervix afferent neurons were identified in the sacral dorsal root ganglia (S1-S3), and 16% in the middle lumbar dorsal root ganglia (L3-L4). In sacral dorsal root ganglia, VIP was present in the highest percentage of dye-labeled cells (71%), CGRP in 42%, and substance P in 18% of the cells. CCK and LENK were present in 13% of the cells. In lumbar dorsal root ganglia, CGRP (51%) was most prominent peptide followed by VIP (34%), substance P (28%), LENK (17%) and CCK (13%). Somatostatin was present in the ganglia but did not occur in dye-labeled neurons. In conclusion, the uterine cervix of the cat receives a prominent VIP- and CGRP-containing afferent innervation. The percentage of neurons containing VIP is three to five times higher than the percentage of these neurons in afferent pathways to other pelvic organs. These observations coupled with the results of physiological studies suggest that VIP is an important transmitter in afferent pathways from the cervix.

The plant lectin soybean agglutinin binds to the soma, axon and central terminals of a subpopulation of small-diameter primary sensory neurons in the rat and cat

The distribution of binding of the plant lectin soybean agglutinin to primary sensory neurons has been investigated in the rat and cat. Soybean agglutinin was found to bind to approximately 30% of neurons in the fourth, lumbar dorsal root ganglion of the rat and approximately 50% of neurons in the first, sacral dorsal root ganglion in the cat. Morphometric analysis of these dorsal root ganglia revealed that in both species those neurons which bind soybean agglutinin appear to be a subpopulation of the small-diameter cells. Electron microscopic analysis of the lumbar dorsal roots revealed that soybean agglutinin binds to the plasma membrane of a subpopulation of unmyelinated axons in both species. Myelinated axons did not bind the lectin. In the dorsal horn of the spinal cord, soybean agglutinin bound to components of Lissauer's tract and the superficial laminae (laminae I and II) of the dorsal horn in both species. In the dorsal horn lectin binding was limited to lamina I and the outer portion of lamina II (sublamina II o in the cat, while in the rat lamina I and the entire dorsoventral extent of lamina II (sublaminae II oand II i were labelled. Thirty days following dorsal rhizotomy, soybean agglutinin binding in the superficial dorsal horn, ipsilateral to the rhizotomy, was abolished in both species. These results show the plant lectin soybean agglutinin to be a histochemical marker for the soma and central terminals of a subpopulation of small-diameter sensory neurons in both the rat and cat. It is suggested that soybean agglutinin binding may be used in conjunction with immunohistochemstry to allow identification of putative neurotransmitters within, or in synaptic profiles associated with, the central terminals of small-diameter primary sensory neurons.

The coexistence of neuropeptides in feline sensory neurons

The coexistence of immunoreactivity to the peptides substance P, bombesin, calcitonin gene-related peptide and somatostatin has been determined in single, lumbar and sacral dorsal root ganglion cells in the cat. Colchicine pretreated L7 and S1 dorsal root ganglia were embedded in wax and cut into 5 μm sections. Groups of four, serially adjacent sections were reacted with antisera to one of four peptides using avidin-biotin immunocytochemistry. It was thus possible to determine the coincidence of the four peptides in single cell bodies by examining the immunoreactivity in a ganglion cell in one section and then locating the same cell in three adjacent sections. As a comparison, this procedure was repeated on a different population of ganglion cells using antiserum to substance P, bombesin and calcitonin gene-related peptide only. The results indicate that different combinations of three or four peptides may occur in single, small diameter sensory neurons in the cat. It would appear that immunoreactivity to bombesin and/or calcitonin gene-related peptide coexists with immunoreactivity to substance P in some dorsal root ganglion cells. However, immunoreactivity to each of these peptides was also found to occur alone in single cells. Immunoreactivity to calcitonin gene-related peptide but not to the other three peptides was found to occur in some medium-sized cell bodies (up to 70 μm). Somatostatin-like immunoreactivity was found to have a high level of coexistence with substance P-like immunoreactivity in cells which contained immunoreactivity to these two peptides only. Immunoreactivity to all the four peptides tested was found to occur in 18–26% of ganglion cells which contained at least one peptide.

Propylene Oxide Causes Central-Peripheral Distal Axonopathy in Rats

In Wistar rats subjected daily to a 6-hr exposure of propylene oxide (PO) at a concentration of 1,500 ppm (5 times a wk for 7 wk), ataxia developed in the hindlegs. Myelinated fibers in hindleg nerves and in the fasciculus gracilis showed axonal degeneration, sparing the nerve cell body of the first sacral dorsal root ganglion and myelinated fibers of the first sacral dorsal and ventral roots. These pathologic findings are compatible with central-peripheral distal axonopathy. This is apparently the first animal model of PO neuropathy to be verified histologically.

Afferent fibers in the reproductive system and pelvic viscera of female rats: Anterograde tracing and immunocytochemical studies

Innervation of the female reproductive system provides an important signal for a variety of neuroendocrine reflexes and behaviors in the female rat. Although some studies suggest that afferent feedback from the gonads is involved in the hypothalamic control of gonadal function and pituitary hormone release, the extent and function of afferent feedback from the gonads in these neuroendocrine reflexes has yet to be clarified. Deafferentation studies have provided only partial support for the afferent control of the gonads. Some studies even suggest functional asymmetries in the neural control of the gonads, but knowledge regarding the neuroanatomical substrate for these possible neurogonadal interactions remains incomplete. Studies with retrograde tract tracers indicate that the ovaries receive a substantial afferent supply from lower thoracic-upper lumbar dorsal root ganglia. Despite stringent precautions to prevent diffusion of tracers following injections into the ovary or related nerves, many of the retrogradely labeled cell bodies identified by these studies may represent an overestimation of the extent of afferent innervation. We have reexamined the afferent innervation of the female reproductive tract by means of the anterograde transport of horseradish peroxidase (HRP) from thoracic, lumbar and sacral dorsal root ganglion to pelvic visceral organs and have studied the effects of unilateral ganglionectomy on substance P containing fibers in the ovary, oviduct and uterus. The neuroanatomical results show that the T 13 and L 1 dorsal root ganglia provide major afferent innervation to the cranial portion of the reproductive tract and the L 6 and S 1 dorsal root ganglia provide primary afferent fibers to the caudal portion of the reproductive tract as well as the bladder, rectum and perineum. Numerous afferent fibers accompany the ovarian artery and the majority of these fibers continue past the ovary towards the oviduct and uterus. Afferent fibers were identified throughout the entire length of the uterine horns but they were generally widely dispersed. In contrast, the afferent innervation of the oviducts appeared to be more extensive than the uterine homs. Only 2 out of 14 tracer injections into the T 13 and l 1 dorsal root ganglia produced labeled fibers within the ovary and in both cases, the fibers accompanied blood vessels. However, labeled fibers were generally identified in the ovarian bursa and associated peritoneum following tracer injections into the T 13 and L 1 ganglia. In contrast to the dispersed and modest amount of afferent labeling observed in the cranial portion of the female reproductive tract, HRP injections into the L 6 and S 1 dorsal root ganglia produced many labeled fibers in the cervical portion of the uterus, vagina, base of the bladder and rectum. Also, numerous labeled fibers and nerve bundles supplying the perineum and external genitalia were observed. Innervation of the vagina was generally more extensive than the innervation of the cervix. Numerous HRP labeled fibers were found at the base of the cervix, but afferent fibers were rarely found cranial to the bifurcation of the uterine horns following injections into the L 6 and S 1 dorsal root ganglia. Substance P immunocytochemistry indicated numerous substance P-like immunoreactive fibers in the oviducts, a moderate numbers of substance P-like fibers in the uterine homs and a few substance P-positive fibers in the ovary. This was the same relationship in terms of numbers of afferent fibers revealed by the neuroanatomical results. Unilateral removal of the T 13 and l 1 dorsal root ganglia eliminated or markedly reduced the number of substance P-like immunoreactive fibers in the uterine horn, oviduct, ovary and ovarian bursa on the same side as the surgery, relative to the unoperated side and sham operated animals. These results verify a dual origin of the afferent innervation to the female reproductive system. The cranial structures receive a modest and diffuse afferent supply from the thoraco-lumbar dorsal root ganglia via the ovarian and hypogastric nerves and the caudal portion of the reproductive tract, as well as the bladder, rectum and perineum, receive an extensive afferent innervation from the lumbo-sacral dorsal root ganglia via the pelvic and pudendal nerves. Finally, these results indicate that there is a modest afferent innervation to the ovarian bursa and surrounding peritoneum but a very limited number of afferent fibers enter the gonad. This verifies the presence of afferent fibers to the ovary and its bursa, but the functional role of this limited afferent pathway in gonadal regulation remains to be clarified.

Electrophysiological characteristics of hamster dorsal root ganglion cells and their response to axotomy.

1. The active and passive membrane properties of neurons in the lower lumbar (L6, L7) or sacral (S1) dorsal root ganglia from golden hamsters were examined in vitro by means of conventional intracellular recording techniques. Data were collected from neurons exhibiting action potentials (AP) of 70 mV or more in amplitude. 2. Cells with axonal conduction velocities (CV) greater than 20 m/s were termed fast-A-cells, those with CVs between 2.5 and 20 m/s were termed A-delta-cells, and those with CVs less than 1 m/s were termed C-cells. 3. Fast-A-cells usually exhibited short-duration APs (2.51 +/- 0.41 ms, n = 19) followed by short (less than 50 ms) afterhyperpolarizations (AHPs). C-cells usually exhibited long-duration APs (10.5 +/- 0.69 ms, n = 18) followed by long-duration AHPs (much greater than 50 ms). The characteristics of APs in A-delta-cells (AP mean duration 3.34 +/- 0.42 ms, n = 32) were intermediate between those of fast-A- and C-cells. Long AHPs (duration much greater than 50 ms) were manifest in 43.8% of A-delta-cells. 4. A time-dependent sag in hyperpolarizing electrotonic potentials (rectification) was found in 68.8% of fast-A-cells, 45.5% of A-delta-cells, and 62.5% of C-cells. 5. To examine neuronal properties 1-6 wk after transection of the sciatic nerve (axotomy), cells were reclassified as SAP (short action potential) cells and LAP (long action potential) cells. Cells in the SAP category had AP durations less than 5 ms and included all fast-A-cells and the majority of A-delta-cells. The LAP category included cells with AP durations greater than 8 ms contained only C-cells. 6. Axotomy failed to decrease the CV of LAP cells or A-delta-cells in the SAP group. The CV of LAP cells may have increased (P less than 0.05), whereas that of SAP cells was unchanged. 7. The duration of the AP and AHP of SAP cells were slightly increased (0.1 greater than P greater than 0.05), whereas AP and AHP duration of LAP cells were unchanged after axotomy. AHP amplitudes of all cell types tended to be smaller (0.1 greater than P greater than 0.05). Axotomy did not alter the resting membrane potential or reduce the incidence of rectification in any cell type. 8. Invasion of the soma by axonally evoked APs was impeded in all cell types after axotomy even though a decrease (P less than 0.05) in rheobase of SAP cells occurred.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunoreactive dynorphin B in sacral primary afferent fibers of the cat

Immunocytochemical analysis of the distribution of dynorphin B terminals in the sacral spinal cord of the cat revealed a pattern of staining very similar to that produced with antisera directed against the primary afferent derived, putative neurotransmitter, vasoactive intestinal polypeptide. Labeled axons and terminals were concentrated in lamina I and V and there was dense fiber staining in the tract of Lissauer. Of particular interest was the presence of immunoreactive axons in attached dorsal rootlets. To specifically focus on the possibility that some of the sacral primary afferent fibers are dynorphin-immunoreactive, we first tried to increase perikaryal labeling in the sacral dorsal root ganglia by topical treatment with colchicine. This did not produce immunoreactive labeling of cell bodies in the ganglia. Unilateral multiple dorsal rhizotomy (L5 to coccygeal 1), however, significantly decreased the staining of dynorphin-immunoreactive axons and terminals in the tract of Lissauer and in the dorsal horn of sacral segments ipsilateral to the deafferentation. No changes were detected in the lumbar cord. Finally, radioimmunoassay of caudal lumbar and sacral dorsal root ganglia was performed. Measurable immunoreactivity was found in all ganglia assayed, but, consistent with the histochemical analysis, sacral ganglia contained the highest concentration of immunoreactive dynorphin B. These data indicate that a significant component of the sacral spinal cord dynorphin terminal immunoreactivity derives from primary afferent fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

The components of the hypogastric nerve in male and female guinea pigs

A quantitative study has been made of the neural components of the hypogastric nerves of male and female guinea pigs using retrograde transport of horseradish peroxidase (HRP) to identify the population of neurones projecting in the nerve trunk, and electronmicroscopic analysis of the myelinated and unmyelinated axons present. Application of HRP to the transected axons of the hypogastric nerve labelled the cell bodies of sensory neurones in lumbar and sacral dorsal root ganglia, preganglionic neurones in the lumbar and sacral spinal cord, and postganglionic neurones in the inferior mesenteric ganglion and in the lumbar paravertebral chain; some ganglion cells of the pelvic plexus were also labelled. The number and distribution of each type of neurone with axons in the hypogastric nerve differed between the sexes: in particular, about twice as many preganglionic axons were present in the male as in the female.

Vasoactive intestinal polypeptide in visceral afferent pathways to the sacral spinal cord of the cat

Immunohistochemical studies revealed that vasoactive intestinal polypeptide (VIP) is localized primarily to sacral segments of the cat's spinal cord. VIP is most prominent in afferent axons and terminals in Lissauer's tract and in lateral laminae I and V of the dorsal horn. The distribution of VIP terminals is very similar to that of visceral afferent projections identified by horseradish peroxidase. Dyetracing experiments combined with immunohistochemistry demonstrated that VIP is located in visceral afferent perikarya in the sacral dorsal root ganglia and also in terminals in the sacral autonomic nucleus. These observations suggest that VIP is a neurotransmitter in afferent projections from the pelvic viscera.

Latent Herpes Simplex Virus Infection of Mice

C-57 albino weanling mice were latently infected with herpes simplex virus (Mp strain, type 1) by inoculation of 10(4) plaque forming units in the right hind footpad. The virus was demonstrable in explant cultures of the sacral dorsal root ganglia of these mice for as long as 18 months following inoculation. In addition, the virus was detectable when homogenates of these latently infected ganglia were placed on to differentiated organotypic cultures of fetal mouse dorsal root ganglia for as long as 8 months following inoculation of the mice. Virus was not demonstrable in these homogenates when they were placed on the Hela cells. The results suggest that during herpes simplex virus latent infection in mice there is continuous synthesis of infectious virus, probably in a highly localized area, which is detectable if a sensitive indicator substrate, such as these organotypic cultures, is used.