Neurokinin A and galanin in the thyroid gland: neuronal localization

Localization and role of galanin in the thyroid gland of Podarcis sicula lizard (reptilia, lacertide)

Galanin (GAL) is a 29-amino acid residue neuropeptide, which was initially isolated from porcine intestine extracts and since then, widely found in a variety of vertebrate organs, in correlation with multiple neuro-hormonal actions exerted and so receiving a constantly growing attention. Moreover, although the studies undertaken so far suggest a local intrathyroidal peptidergic regulatory action, the exact role of GAL on thyroid gland remains to be established. The aim of this study was to determine in the lizard, Podarcis sicula, (1) the presence of GAL immunoreactivity in the thyroid gland and (2) the short- and long-term effects of in vivo GAL administration by intraperitoneal injection on thyroid gland physiology. First of all, the presence of GAL in the thyroid gland of P. sicula was demonstrated by immunohistochemical technique (avidin-biotin-peroxidase complex--ABC method). Second, the role of GAL in the control of thyroid gland activity was studied in vivo using light microscopy (LM) technique coupled to a specific radioimmunoassay for thyroid-stimulating hormone (TSH) and thyroid hormones (T(4) and T(3)). Prolonged GAL administration [(0.4 mg/100 g body wt)/day] increased T(4) and T(3) release, but decreased the plasma concentration of TSH. In addition, using LM clear signs of stimulation of the thyroid gland were observed. These findings suggest that systemic administration of GAL was able to stimulate the thyroid gland of the lizard both at morphological and physiological level.

Tachykinin and Tachykinin Receptor of an Ascidian, Ciona intestinalis

Tachykinins (TKs) are the most prevalent vertebrate brain/gut peptides. In this study, we originally identified authentic TKs and their receptor from a protochordate, Ciona intestinalis. The Ciona TK (Ci-TK) precursor, like mammalian gamma-preprotachykinin A (gamma-PPTA), encodes two TKs, Ci-TK-I and -II, including the -FXGLM-NH(2) vertebrate TK consensus. Mass spectrometry of the neural extract revealed the production of both Ci-TKs. Ci-TK-I contains several Substance P (SP)-typical amino acids, whereas a Thr is exceptionally located at position 4 from the C terminus of Ci-TK-II. The Ci-TK gene encodes both Ci-TKs in the same exon, indicating no alternative generation of Ci-TKs, unlike the PPTA gene. These results suggested that the alternative splicing of the PPTA gene was established during evolution of vertebrates. The only Ci-TK receptor, Ci-TK-R, was equivalently activated by Ci-TK-I, SP, and neurokinin A at physiological concentrations, whereas Ci-TK-II showed 100-fold less potent activity, indicating that the ligand selectivity of Ci-TK-R is distinct from those of vertebrate TK receptors. Ci-TK-I, like SP, also elicited the typical contraction on the guinea pig ileum. The Ci-TK gene was expressed in neurons of the brain ganglion, small cells in the intestine, and the zone 7 in the endostyle, which corresponds to the vertebrate thyroid gland. Furthermore, the Ci-TK-R mRNA was distributed in these three tissues plus the gonad. These results showed that Ci-TKs play major roles in sexual behavior and feeding in protochordates as brain/gut peptides and endocrine/paracrine molecules. Taken together, our data revealed the biochemical and structural origins of vertebrate TKs and their receptors.

Excitable properties and underlying Na+ and K+ currents in neurons from the guinea-pig jugular ganglion

Neurons in the superior vagal (jugular) ganglion relay afferent information from thoracic visceral organs and may be important in inflammatory processes due to the peripheral release of bioactive neuropeptides such as substance P. We characterized the excitable properties and underlying voltage-gated Na+ (INa) and K+ (IKv) currents in acutely dissociated guinea pig jugular ganglion neurons with microelectrode and whole-cell patch-clamp recording techniques. Current clamp recordings revealed a resting potential of approx. -55 mV and input resistance of approx. 100 M ohms. Brief depolarizing steps evoked an overshooting action potential (approx. 2 ms duration), fast (< 20 ms duration) afterhyperpolarization (AHPF) sequence in all neurons, followed by a slow (> 1 s) Cd(2+)-sensitive afterhyperpolarization (AHPS) in 45% of the neurons. The AHPS was implicated in limiting repetitive action potential firing during maintained depolarizing steps. The action potential in 15/17 neurons, and a major component of the whole cell INa in 13/13 neurons were insensitive to TTX (1-10 microM), indicating that jugular neurons express predominantly a TTX-resistant type of INa. Cd2+ (200 microM) did not affect action potential repolarization, while tetraethylammonium (TEA; 10 mM) in the presence of Cd2+ markedly prolonged action potential repolarization, and blocked the AHPF in 11/11 neurons. This suggested that the action potential repolarization and the AHPF are mediated by IKv, with little contribution by Ca(2+)-dependent IK (IK(Ca)). Whole cell IKv activated rapidly (tau < 1.5 ms), and inactivated variably over a time period of seconds. IKv activation and inactivation voltage dependencies and TEA sensitivity were compatible with its availability during the action potential and AHPF. Only 1/26 neurons exhibited current with the rapid inactivation kinetics and voltage-dependencies characteristic of classic IA-type current. These results highlight differences in the properties of jugular neurons (e.g., deficiency of rapid IA, and lack of a TTX-sensitive subpopulation), relative to those known for other visceral and somatic afferents, and thus provide a basis for further functional studies.

Immunohistochemical localization of galanin in bovine reproductive organs

The vagina, uterus and oviduct were shown to receive galanin immunoreactive (GAL-IR) nerve fibres, the number of which varied between particular organs. In the ovary, GAL-IR nerves were absent. A small number of these nerves were located in the layers of the oviduct. A moderate number of GAL-IR nerves were situated in the body and uterine horns, whereas the uterine cervix and vagina wall contained a large number of GAL-IR nerve fibres, evenly distributed throughout particular membranes of the organs. GAL-IR nerves were found to contain, simultaneously, either vasoactive intestinal polypeptide (VIP), substance P (SP) or Leu5-enkephalin (ENK). Many of the GAL-IR nerves contained tyrosine hydroxylase (TH). A group of GAL-IR nerves that did not possess immunoreactivity to VIP, SP, ENK or TH was also observed.

Evaluation of the role of mammalian thyroid parafollicular cells

In this report recent views are presented on the role of the parafollicular cells (PF) in the mammalian thyroid. Contemporary studies indicate morphological and functional heterogeneity of the PF cell population. In normal conditions most PF cells synthesize and secrete calcitonin (CT) and therefore they are frequently referred to as C cells. It seems however, that the contribution to the regional intrathyroidal regulation of secretion and growth processes is also an important role of all functionally mature PF cells of APUD (amine precursor uptake and decarboxylation) series. This has been confirmed by the latest reports on PF cells secreting numerous regulatory peptides (RP) usually defined as "paracrine" and/or "autocrine factors". These peptides are produced jointly with other RP in the same PF cells. Some of RP like CT, somatostatin, katacalcin I (CCP-I), CCP-II, gastrin-releasing peptide, thyroliberin and helodermin have been found in the PF cells, exclusively. Other RP, including calcitonin gene-related peptide, N-terminal peptide, neuromedin U, cholecystokinin and secretory peptide-I, have been simultaneously observed in the PF cells and intrathyroidal nerve fibres. Genetic mechanisms involved in RP production in the PF cells and possible path ways by which these peptides affect the adjacent follicular cells in the thyroid are discussed.

Localization of neurokinin A and chromogranin A immunoreactivity in the developing porcine adrenal medulla

The presence of neurokinin A immunoreactivity was studied in the chromaffin cells of the porcine adrenal medulla and in the nerve fibres innervating the adrenal gland during ontogenic development. For comparison, chromogranin A immunoreactivity was used as a marker for chromaffin cells. Whereas chromogranin A was found in chromaffin cells through all steps in embryonic development, three developmental stages of neurokinin A immunoreactivity could be distinguished. In the first and second trimester of gestation, neurokinin A was observed in some groups of chromaffin cells, but no neurokinin-immunoreactive nerve fibres could be detected. In the last trimester of gestation, neurokinin A-reactive chromaffin cells and nerve fibres were both found in adrenal glands. However, in adrenal glands of neonatal piglets, neurokinin A was found only in nerve fibres and not in chromaffin cells. From these results a hypothesis is proposed that neurokinin A might act as a neurotrophic factor in the early stages of the developing porcine chromaffin cells. Biochemical studies are being performed in order to confirm these morphological results and to study the possible role of neurokinin A as a neurotrophic factor in the adrenal gland.

Localization of NADPH-diaphorase reactivity in the chick and mouse thyroid gland

In the present study, nicotinamide adenine dinucleotide hydrogen phosphate-diaphorase (NADPH-d) histochemistry has been used as a marker for nitric oxide synthase (NOS). The colored reaction product, formazan, was localized in neuronal cell bodies, nerve fibers, and vascular endothelium in the thyroid of chick and mouse. In these two animal species, most of the NADPH-d-labeled neuronal cell bodies were found in the thyroid capsule and interfollicular connective tissue while some were associated with blood vessels. Most nerve fibers travelled with blood vessels supplying the thyroid gland, while a few of them were intimately associated with the thyroid follicular cells. Control sections not incubated with beta-NADPH failed to show labeling of the above structures. It is concluded that nitric oxide may play an important role in endocrine secretion by controlling the regional blood flow in the thyroid gland and by directly acting on the thyroid follicular cells.

Neurokinin A in the anterior pituitary of female rats: effects of ovariectomy and estradiol

The effect of acute and chronic ovariectomy and the substitutive treatment with 17-beta estradiol and/or progesterone on anterior pituitary levels of neurokinin A (NKA) was studied in female rats. Acute ovariectomy did not result in significant changes of NKA in the anterior pituitary gland as compared with the levels in diestrous intact rats, but a single injection of 5 micrograms of estradiol in ovariectomized rats significantly decreased NKA levels in the anterior pituitary gland. Progesterone was without effect and did not modify the decrease of NKA in the anterior pituitary gland induced by estradiol. In rats examined 11 to 17 days after ovariectomy, NKA in the anterior pituitary gland was significantly higher than in diestrous intact rats. In the hypothalamus, ovariectomy resulted in decreased levels of NKA in the median eminence-arcuate nucleus. Estradiol significantly reduced NKA stores in the anterior pituitary gland but increased them in the whole hypothalamus and in the median eminence-arcuate nucleus. Thus, estradiol seems to be a powerful regulator of NKA stores in the adenohypophysis and also in the hypothalamus.

The sensory and sympathetic innervation of guinea-pig lung and trachea as studied by retrograde neuronal tracing and double-labelling immunohistochemistry

The sympathetic and sensory innervation of guinea-pig trachea and lung were studied by means of retrograde neuronal tracing using fluorescent dyes, and double-labelling immunofluorescence. Sympathetic neurons supplying the lung were located in stellate ganglia and in thoracic sympathetic chain ganglia T2-T4; those supplying the trachea resided in the superior cervical and stellate ganglia. Retrogradely labelled sympathetic neurons were usually immunoreactive to tyrosine hydroxylase; the majority also contained neuropeptide Y immunoreactivity. However, a small number were non-catecholaminergic (i.e. tyrosine hydroxylase negative), but neuropeptide Y immunoreactive. Within the airways, tyrosine hydroxylase/neuropeptide Y-immunoreactive axons were found in the smooth muscle layer, around blood vessels including the pulmonary artery and vein, and to a lesser extent in the lamina propria. Periarterial axons contained in addition dynorphin immunoreactivity. Sensory neurons supplying the lung were located in jugular and nodose vagal ganglia as well as in upper thoracic dorsal root ganglia; those supplying the trachea were most frequently found bilaterally in the nodose ganglia and less frequently in the jugular ganglia. A spinal origin of tracheal sensory fibres could not be consistently demonstrated. With regard to their immunoreactivity to peptides, three types of sensory neurons projecting to the airways could be distinguished: (i) substance P/dynorphin immunoreactive; (ii) substance P immunoreactive but dynorphin negative; and (iii) negative to all peptides tested. Substance P-immunoreactive neurons innervating the airways invariably contained immunoreactivity to neurokinin A and calcitonin gene-related peptide. Retrogradely labelled neurons located in the nodose ganglia belonged almost exclusively (greater than or equal to 99%) to the peptide-negative group, whereas the three neuron types each represented about one-third of retrogradely labelled neurons in jugular and dorsal root ganglia. Within the airways, axons immunoreactive to substance P/neurokinin A and substance P/calcitonin gene-related peptide were distributed within the respiratory epithelium of trachea and large bronchi, in the lamina propria and smooth muscle from the trachea down to the smallest bronchioli (highest density at the bronchial level), in the alveolar walls, around systemic and pulmonary blood vessels, and within airway ganglia. Those axons also containing dynorphin immunoreactivity were restricted to the lamina propria and smooth muscle. The origin of nerve fibres immunoreactive for vasoactive intestinal polypeptide, of which a part were also neuropeptide Y immunoreactive, could not be determined by retrograde tracing experiments. Vasoactive intestinal polypeptide-immunoreactive fibres terminating within airway ganglia may be of preganglionic parasympathetic origin, whereas others (e.g. those found in smooth muscle) may arise from intrinsic ganglia.(ABSTRACT TRUNCATED AT 400 WORDS)

Coexistence of calcitonin gene-related peptide and galanin immunoreactivity in female rat pelvic and lumbosacral dorsal root ganglia

Coexistence of immunoreactivity for calcitonin gene-related peptide (CGRP) and galanin (GAL) was examined in varicose nerve endings in female rat pelvic paracervical ganglia (PG) and in perikarya of lumbosacral dorsal root ganglia (DRG). Varicose peptide-containing nerves were closely adjacent to somata of neurons in the PG, certain somata being virtually surrounded by immunoreactive varicosities. Some nerve endings were immunoreactive for either CGRP or GAL; in others, immunoreactivity for CGRP and GAL coexisted. Likewise, many perikarya in DRG were CGRP immunoreactive, fewer were GAL immunoreactive, and in some immunoreactivity for CGRP and GAL coexisted. The results suggest there are subpopulations of neuropeptide-containing sensory nerve endings in the PG; some contain CGRP, some contain GAL, and in some CGRP and GAL coexist. These substances contained in sensory nerve endings could have important roles in pelvic ganglionic functions.

Galanin and calcitonin gene-related peptide immunoreactivity in nerves of the rat uterus: localization, colocalization, and effects on uterine contractility

Immunoreactivity to the neuropeptides galanin (GAL) and calcitonin gene-related peptide (CGRP) was examined in nerves in the rat uterus as a prelude to studying their effects on uterine contractility. With immunocytochemical techniques, GAL immunoreactivity (GAL-I) and CGRP-I were localized in myometrial nerves throughout the uterine horns and cervix, with nerves immunoreactive for CGRP being more numerous. Immunocytochemical double-labeling studies revealed GAL coexists with CGRP in a subpopulation of CGRP-I nerve fibers, i.e., GAL-I was not present in all CGRP-I nerves. Effects of these neuropeptides on uterine contractility were examined on in vitro preparations of uterine horns from diethylstilbestrol-treated rats. GAL (10(-5) to 10(-8) M) stimulated uterine contraction in a dose-related manner. CGRP had no effect on basal uterine tension, but CGRP (10(-7) M) reduced GAL-stimulated (10(-7) M) uterine contraction by 92.5%. These results demonstrate that GAL- and CGRP-I are present in, and coexist in, some uterine nerves, presumably afferent nerves. GAL and CGRP could be released from afferent fibers in an "efferent fashion" and influence uterine contractility, GAL having a contractile effect and CGRP having a relaxing effect.

Immunocytochemical localization and development of multiple kinds of neuropeptides and neuroendocrine proteins in the chick ultimobranchial gland

The ultimobranchial gland is an endocrine organ consisting of C cell groups. In chickens, the glands are richly supplied by nerve fibers immunoreactive for neurofilaments. It was found by immunocytochemical staining that C cells of chick ultimobranchial glands showed immunoreactivities for multiple kinds of neuropeptides and neuroendocrine proteins in addition to calcitonin, i.e., calcitonin gene-related peptide (CGRP), somatostatin, neurotensin, chromogranin A, and tyrosine hydroxylase. Furthermore, enkephalin-immunoreactive cells that showed long cytoplasmic processes and large cell bodies, being distinct from the C cell feature, were detected. The densities of these cells per unit area of ultimobranchial gland were assessed using computer-assisted image analysis system; calcitonin cells were 42.9 +/- 10.0%; CGRP cells 26.9 +/- 5.6%; neurotensin cells 8.6 +/- 6.9%; somatostatin cells 3.1 +/- 1.4%; chromogranin A cells 11.8 +/- 1.8%; tyrosine hydroxylase cells 10.0 +/- 5.2%; enkephalin cells 2.9 +/- 1.3%. Dense distributions of peptidergic nerve fibers were also detected in chick ultimobranchial glands. Numerous varicose fibers immunoreactive for substance P were distributed in the close vicinity to C cell clusters and blood vessels. Enkephalin-immunoreactive fibers were also prominent around C cell clusters. Galanin-, vasoactive intestinal peptide (VIP)-, and tyrosine hydroxylase-immunoreactive fibers were distributed around blood vessels only. Subsequently, the ontogeny of these neuropeptides, neuroendocrine proteins, and peptidergic innervations was examined in chickens at various developmental stages. In 10-day-old embryos, weak to moderately intense immunoreactivity for calcitonin was already present in almost all C cells. Immunoreactivities for somatostatin, CGRP, and tyrosine hydroxylase began to appear at this age. At 12 days of incubation, substance P-immunoreactive fibers were first detected in the parenchyma of ultimobranchial glands. Considerable numbers of enkephalin-immunoreactive fibers and cells were also observed. At 14 days of incubation, the largest populations of somatostatin- and enkephalin-immunoreactive cells were attained; the densities of somatostatin- and enkephalin-immunoreactive cells per unit area were 21.2 +/- 3.2% and 12.9 +/- 3.1%, respectively. Substance P-immunoreactive fibers became numerous throughout the gland at this age. Thereafter, calcitonin-, CGRP-, tyrosine hydroxylase-immunoreactive cells progressively increased in number with embryonic age, whereas somatostatin- and enkephalin-immunoreactive cells started to decrease. Chromogranin A- and neurotensin-immunoreactive cells began to appear at 16 days and 18 days of incubation, respectively. Galanin-, VIP-, and tyrosine hydroxylase-immunoreactive fibers were inconspicuous during embryonic life.

Neuromedin U-like immunoreactivity in the thyroid gland of the rat

Neuromedin U is a novel neuropeptide found to have a widespread distribution extending throughout the mammalian central nervous system, gastrointestinal tract and the endocrine cells of the pituitary gland. In order to investigate the possibility that neuromedin U-like immunoreactivity is also present in the thyroid gland of the adult rat we have examined its localisation and molecular nature by radioimmunoassay, immunocytochemistry and chromatographic analysis. The neuromedin U content of the whole thyroid gland was found to be 331 +/- 67 fmol/gland (mean +/- SEM), and this value significantly decreased (163 +/- 17 fmol/gland) as a result of 14 days of treatment with the anti-thyroid agent methimazole (10 mg/rat/day. Thyrotoxicosis induced by exogenous T4 (10 micrograms/rat/day) failed to alter the thyroid content of this peptide. Immunostaining studies localised neuromedin U to a minor population of parafollicular C-cells in untreated animals. Complementary chromatographic studies revealed a single molecular form of neuromedin U-like immunoreactivity in thyroid tissue extracts which was indistinguishable from synthetic rat neuromedin U standard.

Pancreatic nerve stimulation releases neuropeptide Y- but not galanin- or calcitonin gene-related peptide-like immunoreactivity from the pig pancreas

We investigated the possible release of galanin-, calcitonin gene-related peptide (CGRP)-, and neuropeptide Y (NPY)-like immunoreactivity from the pancreatic nerves in thiopental-anaesthetized pigs. Ten minutes stimulation of the mixed autonomic pancreatic nerves during infusion of atropine (8 or 40 Hz, 5 ms, 10 mA, n = 5) inhibited insulin secretion, during both normoglycemia (9.1 +/- 0.2 mmol/l) and hyperglycemia (28.1 +/- 0.4 mmol/l). Concomitantly, pancreatic venous concentrations of NPY-like immunoreactivity increased. For example during normoglycemia, a nerve stimulation by 8 Hz increased the pancreatic venous levels of NPY-like immunoreactivity from 294 +/- 26 pmol/l to 391 +/- 23 pmol/l (P less than 0.001). In contrast, the pancreatic venous concentrations of galanin- or CGRP-like immunoreactivity did not change during the nerve stimulation. We conclude that electrical pancreatic nerve stimulation in the pig releases NPY-like immunoreactivity without affecting the pancreatic venous concentrations of galanin- or CGRP-like immunoreactivity.

Neuropeptide Y and vasoactive intestinal peptide coexist in rat thyroid nerve fibers emanating from the thyroid ganglion

Neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) occur in nerve fibers around blood vessels and between follicles in the thyroid gland of the mouse and rat. VIP-immunoreactive fibers are numerous, while NPY-immunoreactive fibers are fewer. Most of the latter fibers contain noradrenaline (NA) as well as NPY, while a subpopulation was found to contain VIP instead of NA. We have determined the origins of rat thyroid nerve fibers containing NPY, VIP or NPY/VIP by investigating 3 conceivable sources, i.e. the superior cervical ganglion, the nodose ganglion and the thyroid ganglion. Chemical sympathectomy or removal of the superior cervical ganglion did not affect the frequency of VIP-immunoreactive fibers but eliminated most of the NPY-immunoreactive fibers as well as all NA-containing nerve fibers (recognized by antibodies to dopamine-beta-hydroxylase). The NPY-immunoreactive fibers that remained after sympathectomy occurred around blood vessels and between follicles and contained VIP. Cervical vagotomy (removal of the nodose ganglion including the adjacent vagus) did not overtly affect the frequency of NPY/VIP-, VIP-, or NPY/NA-containing fibers in the thyroid. In contrast, extirpation of the thyroid ganglion, which is situated immediately outside the thyroid capsule, greatly reduced the number of VIP- and NPY/VIP-containing fibers in the rat thyroid. On the whole, the results of radioimmunoassay of NPY and VIP agreed well with the immunocytochemical findings. High performance liquid chromatography confirmed the identity of NPY and VIP. The present findings suggest the existence in the rat thyroid of one NPY-containing nerve fiber population that harbours NA and emanates from the superior cervical ganglion; one NPY-containing fiber population that is non-adrenergic, harbours VIP and originates in the thyroid ganglion; and a second VIP-containing fiber population that is devoid of NPY and appears to derive from the thyroid ganglion.

Neuronal pathways to the rat thyroid revealed by retrograde tracing and immunocytochemistry

The distribution and origin of the nerve fibres innervating the rat thyroid were studied by immunocytochemistry, retrograde tracing and denervation experiments. Immunocytochemistry revealed nerve fibres containing noradrenaline, neuropeptide Y, vasoactive intestinal peptide, peptide histidine-isoleucine, galanin, substance P, neurokinin A and calcitonin gene-related peptide around blood vessels and follicles. Many of these transmitter candidates were found to co-exist with each other in different combinations in different subpopulations of neurons. Sympathectomy eliminated all noradrenaline- and noradrenaline/neuropeptide Y-containing fibres in the thyroid. Cervical vagotomy eliminated about 50% of the galanin-, substance P- and calcitonin gene-related peptide-containing fibres. Local denervation (removal of the thyroid ganglion and the thyroid nerve) eliminated all galanin- and substance P-immunoreactive fibres and the majority of noradrenaline-, noradrenaline/neuropeptide Y-, vasoactive intestinal peptide- and calcitonin gene-related peptide-containing fibres in the thyroid gland. Injection of True Blue into the thyroid gland labelled cell bodies in the thyroid ganglion, the laryngeal ganglion, the superior cervical ganglion, the jugular-nodose ganglionic complex, the dorsal root ganglia (C2-C5) and the trigeminal ganglion. Judging from the number of labelled nerve cell bodies, the superior cervical ganglion and the thyroid ganglion contribute most to the thyroid innervation, while the laryngeal ganglion and the trigeminal ganglion contribute least. The True Blue-labelled ganglia were examined for the presence of various populations of nerve cell bodies (only major populations are listed). The thyroid ganglion harboured neuropeptide Y, vasoactive intestinal peptide and galanin/vasoactive intestinal peptide cell bodies (in order of predominance); the laryngeal ganglion galanin/vasoactive intestinal peptide, vasoactive intestinal peptide and calcitonin gene-related peptide cell bodies; the superior cervical ganglion noradrenaline/neuropeptide Y and noradrenaline cell bodies; the jugular ganglion calcitonin gene-related peptide, substance P/calcitonin gene-related peptide and galanin/substance P/calcitonin gene-related peptide cell bodies; the nodose ganglion vasoactive intestinal peptide and vasoactive intestinal peptide/galanin cell bodies; the dorsal root ganglia (C2-C5) and the trigeminal ganglion calcitonin gene-related peptide, substance P/calcitonin gene-related peptide and galanin/substance P/calcitonin gene-related peptide cell bodies.(ABSTRACT TRUNCATED AT 400 WORDS)