Immunohistochemical evidence for extrinsic and intrinsic opioid systems in the guinea pig superior cervical ganglion

Summary Immunohistochemical localization of the opioid peptides -neo-endorphin (-neo-END), dynorphin A (DYN) and leu-enkephalin (leu-ENK) in the guinea pig superior cervical ganglion (SCG) was studied following central denervation, peripheral axotomy, and after application of the depleting drug reserpine and of the neurotoxin 6-hydroxydopamine. The paraganglionic cells of the SCG are shown to form an intrinsic opioid — (-neo-END, DYN, leu-ENK) — immunoreactive system being not visibly responsive to the experimental procedures. Leu-ENK-immunoreactive fibres ascend in the preganglionic trunk and supply fibre baskets to defined clusters of postganglionic neurones. Principal ganglion cells of the SCG containing -neo-END-and DYN-immunoreactivity project to extraganglionic targets via the postganglionic nerves. These findings are indicative of a sympathetic -neo-END-ergic and DYN-ergic innervation of effector organs. They also point to a modulatory function of opioids on neuronal activity in a paravertebral ganglion.     

Expression of preproenkephalin mRNA in rat superior cervical ganglion during postnatal development

The number of principal neurons in the rat superior cervical ganglion (SCG) exhibiting enkephalin-peptide immunoreactivity is reported to be limited. To better determine the degree of enkephalinergic phenotype in sympathetic neurons, sections of SCGs from rats aged newborn to adult were processed for in situ hybridization histochemistry, using a [³⁵S]cRNA probe directed against preproenkephalin (PPENK). > 50% of principal ganglion neurons express mRNA for PPENK in adults. Striking variability in labeling intensity is observed. PPENK mRNA is detected in developing ganglia beginning at postnatal days 4–7. Both the number of cells and intensity of labeling increases with postnatal development. These results indicate that expression of PPENK mRNA is more widespread than expression of enkephalin peptides and develops postnatally.     

Sodium and calcium currents of acutely isolated adult rat superior cervical ganglion neurons

Neurons enzymatically isolated from the adult rat superior cervical ganglion (SCG) were investigated using the whole-cell variant of the patch-clamp technique. Currentclamp studies revealed the following mean passive and active membrane properties: resting membrane potential, –54.9 mV; input resistance, 349 M; action potential (AP) threshold, –29.8 mV; AP overshoot, 53.3 mV; AP maximum rate of rise, 166.4 V/s; and AP duration, 3.2 ms. Chemosensitivity to acetylcholine remained intact following enzymatic dispersion. Voltage-clamp studies of a transient tetrodotoxin-sensitive Na⁺ current revealed activation and inactivation processes which could be fit to modified Boltzmann equations. Na⁺ current activation parameters for the half activation potential (Vh) and slope factor (K) were –23.3 mV and 5.3 mV, respectively. Inactivation parameters forVh andK were –59.3 mV and 7.6 mV, respectively. Voltage-clamp studies also revealed a high voltageactivated sustained inward current which was eliminated upon removal of external Ca²⁺, greatly reduced by 500 M Cd²⁺, and supported by Ba²⁺ or Sr²⁺. Tail current analysis of this Ca²⁺ current revealed a sigmoidal activation. A low voltage-activated transient Ca²⁺ current was not observed. We conclude that isolated SCG neurons retain the properties of neurons in intact ganglia and provide several advantages over conventional preparations for the study of voltagegated membrane currents.     

Eugenol modifies the excitability of rat sciatic nerve and superior cervical ganglion neurons

Eugenol is a phenylpropene obtained from the essential oils of plants such as clove and basil which has ample use in dentistry. Eugenol possesses analgesic effects that may be related to the inhibition of voltage-dependent Na⁺ channels and/or to the activation of TRPV1 receptors or both. In the present study, electrophysiological parameters were taken from the compound action potentials of the isolated rat sciatic nerve and from neurons of the superior cervical ganglion (SCG) impaled with sharp microelectrodes under current-clamp conditions. In the isolated rat sciatic nerve, eugenol inhibited the compound action potential in a concentration-dependent manner. Action potentials recorded from SCG neurons were inhibited by eugenol with an IC₅₀ of 0.31 mM. At high concentrations (2 mM), during brief applications, eugenol caused significant action potential blockade while it did not interfere with the resting membrane potential or the membrane input resistance. Surprisingly, however, at low eugenol concentrations (0.6 mM), during long time applications, a reversible reduction (by about 50%) in the input membrane resistance was observed, suggesting the possible involvement of a secondary delayed effect of eugenol to reduce neuronal excitability.     

Neurochemical properties of the middle cervical ganglion in the sheep

The neurochemical properties of the ovine middle cervical ganglion (MCG) were studied using antibodies raised against tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH), neuropeptide Y (NPY), substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and galanin (GAL). Double-labelling immunocytochemistry revealed that the vast majority (95.5 +/- 0.8%) of postganglionic sympathetic MCG neurons expressed simultaneously both catecholamine-synthesizing enzymes (neurons were TH/DbetaH-positive). A large population of noradrenergic neurons exhibited immunoreactivity (IR) to NPY (62.2 +/- 2.2%), but single NPY-positive perikarya-lacking noradrenergic markers were also observed (2.0 +/- 0.3%). None of the examined MCG neuronal somata contained SP, CGRP, GAL or VIP. A moderate number of noradrenergic nerve fibres located amongst neuronal cell bodies was also found. In small number of these terminals the presence of NPYor GAL (but not CGRP or VIP) was detected. The ovine MCG was numerously innervated with SP-immunoreactive nerve fibres which sometimes formed basket-like formations around postganglionic neurons. The MCG exhibited a sparse CGRP-immunoreactive innervation and lacked VIP-positive nerve terminals. In many aspects the chemical coding of MCG postganglionic neurons and nerve terminals resembles that found in other mammalian cervico-thoracic paravertebral ganglia, but some important species-dependent differences exist. The functional implications of these differences remain to be elucidated.     

Peptide 19 in the rat superior cervical ganglion

Peptide 19 is a 7.6 kDa polypeptide which can bind to calmodulin and inhibit calcium-calmodulin signaling. In this study, peptide 19-immunoreactivity was examined in the rat superior cervical ganglion. In the ganglion, 54.8% of postganglionic sympathetic neuron profiles were immunoreactive for peptide 19. These neuron profiles were small- to medium-sized and measured 87–845 μm² (mean±SD=343±111 μm²). Double immunofluorescence method revealed that 99.9% of peptide 19–containing neurons had neuropeptide Y in the superior cervical ganglion. Retrograde neuronal tracing and immunohistochemical studies also demonstrated that peptide 19 was common in postganglionic sympathetic neurons which innervated the facial skin and masseter but not the submandibular gland; 55.6% and 75.2% of cutaneous and muscular neuron profiles, respectively, contained peptide 19. Only 9.8% of glandular neurons were immunoreactive for peptide 19. These findings indicate that the content of peptide 19 in superior cervical ganglion neurons depends on their cell sizes and peripheral projections. On the other hand, colchicine injection into the superior cervical ganglion decreased the number of peptide 19–positive neurons (30.7%) compared to saline injection (53.3%). In contrast, the treatment induced nicotine adenine dinucleotide phosphate diaphorase activity in 12.7% of postganglionic sympathetic neurons. Double stain demonstrated that 56.3% of nicotine adenine dinucleotide phosphate diaphorase–positive neurons co-expressed peptide 19. These findings indicate that colchicine treatment causes decrease of peptide 19 expression and increase of nitric oxide synthase activity.     

兔颈上神经节神经元的急性分离及其通道电流记录

目的 探讨兔颈上神经节神经元分离及电生理研究的方法.方法 为了获得适用于膜片钳实验技术的单个颈上神经节神经细胞,应用酶和机械分离相结合的方法,急性分离20～30 d幼兔的单个颈上神经节神经元.通过倒置显微镜直接观察以及全细胞膜片钳技术的电压钳和电流钳分别对分离得到的颈上神经节神经元的形态学和电生理学特性进行研究.结果 急性分离所得活性较好的颈上神经节神经元胞体具有圆形和顶树突特征,立体感强,光晕明显.在全细胞膜片钳记录模式下可记录到全细胞电流、钠电流、钾电流及动作电位.结论 该方法可以得到形态和生理特性良好的单个颈上神经节神经元;该方法适用于膜片钳技术的研究,对深入探讨药物、物理因子等对神经节神经元离子通道的影响具有重要的应用价值.     

NOS-positive preganglionic neurons innervate a subpopulation of postganglionic neurons in superior cervical ganglion in rats

To determine the postganglionic targets of NOS-containing preganglionic neurons, we studied the association of NADPH-diaphorase positive preganglionic fibers and retrogradely labeled postganglionic neurons in the superior cervical ganglion (SCG) in rats. Wheat germ agglutinin-horseradish peroxidase solution was applied to the anterior chamber of the eye, middle cerebral artery, subcutaneous layer of the facial skin, or submucosal layer of the inside of the lip. Two days after tracer application, the rats were perfused with fixative solution. Serial sections of the SCG were stained histochemically for NADPH-diaphorase followed by diaminobenzidine reaction. More than 80% of the labeled postganglionic neurons innervating the structures in the subcutaneous or submucosal layer showed close association with NADPH-diaphorase positive preganglionic nerve terminals; approximately one-third of these labeled neurons were encircled by dense baskets of pericellular terminals. On the other hand, most of the postganglionic neurons innervating the iris (69%) or the cerebral artery (90%) did not show a distinct association with NADPH-diaphorase positive terminals. These results suggest that one of the principal roles of the NOS-containing preganglionic neurons may be in controlling the postganglionic neurons which innervate the structures in the subcutaneous or submucosal layer.     

Secretoneurin-immunoreactivity in nerve terminals apposing identified preganglionic sympathetic neurons in the rat: colocalization with substance P and enkephalin

Preganglionic sympathetic neurons projecting to the superior cervical ganglion are innervated by nerve fibers containing classical neurotransmitters as well as neuropeptides. In this study we examined the possible participation of a novel peptide, secretoneurin (a cleavage product of secretogranin II), in regulation of sympathetic outflow to head and neck by using a retrograde labelling-technique combined with immunohistochemistry. In addition, the coexistence of secretoneurin with substance P and leu-enkephalin, peptides known to innervate preganglionic neurons, was investigated. The majority of retrogradely labeled neurons were localized in the nucleus intermediolateralis of spinal cord segments T1–T3 (maximum at T2). Nearly all of Fast Blue positive neuronal perikarya were apposed by nerve fibers and terminals exhibiting immunoreactivity to secretoneurin. The main secretoneurin-immunoreactive form found in the upper thoracic segments corresponded to the free peptide secretoneurin as revealed by chromatography and radioimmunoassay. More than half of labeled neurons were surrounded by nerve endings containing in addition substance P or leu-enkephalin which were also, however, less frequently colocalized. Our results suggest that secretoneurin influences the activity of preganglionic sympathetic neurons projecting to the superior cervical ganglion. Regarding their frequent colocalization with substance P and leu-enkephalin, functional interactions of these peptides on preganglionic sympathetic nerve activity have to be considered.     

The substance P innervation of the rat hippocampal region

Summary The distribution of substance P (SP) immunoreactive nerve cell bodies and preterminal processes was studied in the rat brain by using several anti-SP-antibodies in combination with immunohistochemical techniques. In normal rats and in rats pretreated with colchicine, SP immunoreactive preterminal processes were found in the hippocampal region, but SP positive cellbodies could be detected only after colchicine pretreatment. Medium-sized to large, multipolar cells immunoreactive for SP were found in stratum oriens of the hippocampal subfield CA3 and in the hilus of the area dentata. Medium-sized to small, round or fusiform cells were detected in the pyramidal layer of the ventral subiculum and in layers III–VI of the ventral entorhinal area. The SP stained preterminal processes were of two types. Numerous fine, varicose axons were stained in different parts of Ammon's horn, while in the retrohippocampal structures, the SP immunoreactivity was present in small distinctly stained puncta. These frequently formed pericellular arrangements around unstained cells, indicative of axosomatic contacts between SP terminals and cells in the hipocampus. In Ammon's horn, the densest SP innervation was found in strata oriens, radiatum and moleculare of subfields CA3a and CA2. Scattered fibers were also present in the stratum oriens of CA3a-c and in the hilus, in particular at ventral levels. In retrohippocampal structures, the SP innervation predominated in the deep pyramidal layer of the subiculum, the second layer of the presubiculum and in layers VI and IV of the medial and lateral entorhinal area. Many of these terminals may arise from local interneurons as well as from sources outside the hippocampal region.Taken together, these studies demonstrate a far more extensive innervation by SP, or a closely related peptide, of the rat hippocampal region than was previously recognized. This suggests that SP may play an important role in neurotransmission within the hippocampal region.Stephen Davies was supported by Travel grants from the Wellcome Trust and the Gurantors of Brain.     

Immunohistochemical evidence for separate populations of somatostatin-containing and substance P-containing primary afferent neurons in the rat

The localization of two small peptides, somatostatin and substance P, has been studied with the indirect immunofluorescence technique. Both peptides were present in small neuronal cell bodies in spinal ganglia, in fibers in the dorsal horn of the spinal cord and in fibers in the intestinal wall. By comparing consecutive sections incubated with antisera to somastostatin and to substance P respectively, it was established that somatostatin, or somatostatin-like immunoreactivity and substance P, or substance P-like immunoreactivity are present in different cells. This is possibly indicated also by a somewhat differential distribution of the immunoreactive fibers in the dorsal horn: the highest concentration of somatostatin-positive fibers was observed in lamina II, whereas abundant substance P-positive fibers were present also in lamina I. Furthermore, numerous substance P-, but no somatostatin-positive fibers, were found around the central canal and in the ventral horns. In the intestinal wall more substance P-positive than somatostatin-positive fibers were seen.The present results indicate that two subpopulations of primary sensory neurons exist, one containing somatostatin, or somatostatin-like immunoreactivity, and the other containing substance P, or substance P-like immunoreactivity.     

Origin and fine structure of substance P-containing nerve terminals in the facial nucleus of the rat: an immunohistochemical study

Summary The distribution, origin and fine structure of substance P-like immunoreactive (SPI) nerve terminals in the facial nucleus of the rat were investigated by means of immunocytochemistry. SPI-terminals were concentrated in the intermediate and dorsal subnuclei of the facial nucleus. Hemi-transection of the brainstem just rostral to the facial nucleus or at the most caudal level of the medulla oblongata did not cause any change of SPI-terminals in the facial nucleus. Electrical destruction of the various parts of the medulla oblongata clearly demonstrated that SPI-terminals in the intermediate subnucleus were supplied contralaterally from the SPI-neurons in the dorsomedial part of the medullary reticular formation. Most of the SPI-terminals (85%) in the intermediate subnucleus of the facial nucleus were observed to make asymmetric synaptic contacts with large dendrites (mean diameter; 1.26 m). It was supposed that the contact sites are located on proximal parts of the dendrite. A few SPI-terminals (6%) formed axo-somatic contacts with large perikarya filled with numerous cytoplasmic organelles.Abbreviations used in Figures A n. ambiguus - AP area postrema - C n. cuneatus - Cod n. cochlearis dorsalis - Cov n. cochlearis ventralis - CU n. cuneiformis - FLM fasciculus longitudinalis medialis - G n. gracilis - MRF midbrain reticular formation - nts n. tractus solitarius - nVsp n. tractus spinalis nervi trigemini - nVII n. originis nervi facialis - nX n. originis dorsalis vagi - nXII n. originis nervi hypoglossi - OI n. olivaris inferior - rfl the ventro-lateral part of the caudal medullary reticular formation - rfm the dorso-medial part of the medullary reticular formation - RL n. reticularis lateralis - RM n. raphe magnus - rmg n. reticularis magnocellularis - RO n. raphe obscurus - sgc substantia grisea centralis - Vl n. vestibularis lateralis - Vm n. vestibularis medialis - Vsp n. vestibularis spinalis     

氟伐他汀对心肌缺血兔颈上神经节神经元延迟整流钾通道特性的影响

目的 探讨氟伐他汀对心肌缺血情况下支配心脏的颈上交感神经节(SCG)神经元电生理特性的影响.方法 利用异丙肾上腺素皮下注射(85 mg·kg-1 ·d-1,共2d)制作兔急性心肌缺血模型,通过全细胞膜片钳技术研究对照组、心肌缺血组及氟伐他汀(10 mg· kg-1·d-1,共7d)干预组的SCG神经元延迟整流钾通道特性的改变.结果 对照组、缺血组和氟伐他汀干预组的兔SCG神经元的延迟整流钾通道最大峰值电流幅值分别为(80.80±22.80) pA/pF、(154.93±31.56) pA/pF、(119.82±24.82)pA/pF,3者的半数激活电压分别为(9.86±0.57)mV、(12.36±1.09) mV和(9.52±0.49) mV,斜率因子分别为(19.66±0.75)mV、(27.33±1.64) mV和(17.76±0.61) mV.急性心肌缺血使SCG神经元延迟整流钾通道电流(IK)幅度增大,氟伐他汀的干预可一定程度上使这种增大的电流有所减小.同时,氟伐他汀干预可使心肌缺血组移动的激活曲线向对照组方向移动.结论 心肌缺血情况下SCG神经元延迟整流钾通道特性产生的变化可一定程度上通过氟伐他汀的干预得到修复,这可能是氟伐他汀治疗心脏疾病的机制之一.     

A qualitative and quantitative study of substance P immuno-cytochemistry of the trigeminal ganglion in the monkey

The immunoreactivity of substance P(SP) in the monkey trigeminal ganglion was examined and the distribution of immunoreactive cells determined. The monkey trigeminal ganglion is composed of clusters of sensory cells arranged in cords parallel to the long axis of the nerve fibres. The cells have prominent nuclei and are surrounded by satellite cells. Abundant organelles are randomly distributed throughout the cytoplasm. A striking feature of the ganglion was the presence of some axon-like prolifes containing mainly dense-cored vesicles and some agranular vesicles. Between 16 and 32% of the ganglion cells displayed SP-immunoreactivity. Most of the SP-IR cells were unipolar, small to medium-sized ganglion cells and they had no specific pattern of distribution. The staining of the SP-IR cells varied considerably, ranging from weak or moderate to heavy staining, although the majority of them were moderately stained. Immuno-electron microscopy showed that the SP-IR products were distributed throughout the soma of ganglion cells and not associated with any particular organelles or inclusions. The reaction products were also found in both myelinated and unmyelinated fibres between the ganglion cells. Another remarkable feature of the trigeminal ganglion was the occurrence of some SP-IR nerve fibres forming a rich glomerular network of pericellular arborizations around some of the SP-negative cells. Ultrastructural study showed the presence of some SP-IR nerve terminals in close approximation to some SP-negative cells, but there were no synaptic contacts. The relative frequency of the SP-IR pericellular arborizations paralleled the frequency of all the SP-IR cells. The results may imply that the pericellular arborizations function as a medium of communication between SP-positive and SP-negative sensory cells within the ganglion. It was suggested that the fibres forming the pericellular arborizations may originate from the intrinsic ganglion cells that are SP-positive.     

Immunohistochemical localization of substance P and substance P receptor (NK1) in the olivary pretectal nucleus of the rat

The olivary pretectal nucleus (OPN) is the first central nucleus in the pupillary light reflex arc (PLR). Substance P (SP) is a neuropeptide present in the OPN. The present immunohistochemical study, performed at the ultrastructural level, aimed to determine the synaptic localization of SP and SP receptor in the OPN. Three types of SP-positive terminals were found. The most abundant type was of retinal origin, characterized by electron-lucent mitochondria and round vesicles, organized in glomerular structures, making asymmetric synaptic contacts with dendrites, and profiles containing pleomorphic vesicles, also making synaptic contacts with dendrites. The second type of SP-immunoreactive terminal contained electron-dense mitochondria and pleomorphic vesicles. This type made symmetric synaptic contacts and may originate from the ventral part of the lateral geniculate nucleus. The third type of SP-immunoreactive terminals contained electron-dense mitochondria, clear round vesicles, and made an asymmetric synaptic contact. This type originates from the contralateral OPN. SP receptors of the NK1 subtype were revealed to be on dendrites and were part of the glomerular-like arrangement. On account of the present observations, it can be concluded that retinal projections to the OPN use SP as a neuromodulator and synapse on NK1 receptor-containing dendrites of large neurons projecting to the Edinger-Westphal nucleus. Since SP also modulates the parasympathetic component of the PLR, we postulate that SP plays a modulating role in all components of the PLR.     

Labelling of schwann and satellite cells by [3H]dexamethasone in a rat sympathetic ganglion and sciatic nerve

Light-microscopic autoradiograms of superior cervical ganglia of adult rats after injection of [³H]dexamethasone showed a preferential accumulation of radioactivity in the nuclei of satellite and Schwann cells. The total radioactivity found in the ganglion at 10 min after injection was high compared to the cerebral cortex of the brain, but declined rapidly. Only Schwann and satellite cell nuclei retained the label for up to 2 h. The labelling was specific for dexamethasone, since it could be prevented by an excess of unlabelled dexamethasone but not by corticosterone. Administration of [³H]corticosterone resulted in only a weak labelling of the ganglion and no specific labelling of Schwann and satellite cells could be observed. As in the ganglion, accumulations of [³H]dexamethasone by Schwann cell nuclei was also observed in the sciatic nerve.It is possible, therefore, that satellite and Schwann cells represent an important target for glucocorticoids in the nervous system.     

A survey of substance P, somatostatin, and neurotensin levels in aging in the rat and human central nervous system

Levels of the neuropeptides substance P, somatostatin, and neurotensin were measured by radioimmunoassay in regions of the rat and human central nervous system (CNS) in aging. Somatostatin levels were significantly lower only in the corpus striatum of older rats. Substance P levels and neurotensin levels were generally stable with aging as were levels of somatostatin in regions other than the corpus striatum. In post-mortem human CNS tissues, no significant negative correlations of levels of the three peptides were observed with time to refrigeration or time to freezer for the samples. In the human CNS, there were no significant age-related alterations in substance P levels in frontal cortex, thalamus, hypothalamus, caudate nucleus, globus pallidus, or substantia nigra. There was a significant age-related decrease in substance P levels in the human putamen. This age-related decrease was not present in tissues from victims of Huntington's disease nor was there any striking difference in substance P levels as a function of duration of the disease. There were no significant age-related changes in somatostatin levels in human frontal cortex, caudate nucleus, putamen, medial globus pallidus, or substantia nigra. Among these same regions, there was a significant age-related decrease in neurotensin levels only in the pars compacta and pars reticulata of the human nigra. These results implicate neuropeptides in aging processes in certain regions of the CNS. There are differences between rats and humans with respect to neuropeptides in the aging process in the CNS. Deterioration of some neuropeptide pathways in and to human basal ganglia may be involved in the suspected functional deterioration of parts of the extrapyramidal system in aging.     

A survey of substance P, somatostatin, and neurotensin levels in aging in the rat and human central nervous system

Levels of the neuropeptides substance P, somatostatin, and neurotensin were measured by radioimmunoassay in regions of the rat and human central nervous system (CNS) in aging. Somatostatin levels were significantly lower only in the corpus striatum of older rats. Substance P levels and neurotensin levels were generally stable with aging as were levels of somatostatin in regions other than the corpus striatum. In post-mortem human CNS tissues, no significant negative correlations of levels of the three peptides were observed with time to refrigeration or time to freezer for the samples. In the human CNS, there were no significant age-related alterations in substance P levels in frontal cortex, thalamus, hypothalamus, caudate nucleus, globus pallidus, or substantia nigra. There was a significant age-related decrease in substance P levels in the human putamen. This age-related decrease was not present in tissues from victims of Huntington's disease nor was there any striking difference in substance P levels as a function of duration of the disease. There were no significant age-related changes in somatostatin levels in human frontal cortex, caudate nucleus, putamen, medial globus pallidus, or substantia nigra. Among these same regions, there was a significant age-related decrease in neurotensin levels only in the pars compacta and pars reticulata of the human nigra. These results implicate neuropeptides in aging processes in certain regions of the CNS. There are differences between rats and humans with respect to neuropeptides in the aging process in the CNS. Deterioration of some neuropeptide pathways in and to human basal ganglia may be involved in the suspected functional deterioration of parts of the extrapyramidal system in aging.     

Collateral projections of trigeminal ganglion neurons to both the principal sensory trigeminal and the spinal trigeminal nuclei in the rat

Employing a combination of fluorescent retro grade double labelling and immunofluorescence histo chemistry for substance P (SP) and calcitonin gene-relat ed peptide (CGRP), we examined collateral projections from single neurons in the trigeminal ganglion (TG) of the rat to both the principal sensory trigeminal nucleus (Vp) and the oral, interpolar or caudal subnuclei of the spinal trigeminal nucleus (Vo, Vi or Vc). In the rats that were unilaterally injected with fast blue (FB) into the Vp and with diamidino yellow (DY) into the Vo, Vi or Vc, neurons labelled with FB and/or DY were observed in the TG ipsilateral to the injections. Of the labelled TG neurons, about 2% were double labelled with both trac ers in the rats that were injected with FB into the Vp and with DY into the Vo or Vi, and about 10% were double labelled in the rats that were injected with FB into the Vp and with DY into the Vc. The results indicate that TG neurons sending their axons to the Vp project, by way of axon collaterals, to the Vc more frequently than to the Vo or Vi.Some of the TG neurons double labelled with FB and DY exhibited SP-or CGRP-like immunoreactivity (LI): Of the TG neurons that were double labelled with FB injected into the Vp and with DY injected into the Vo, Vi or Vc, about 38%, 49% and 42%, respectively, displayed SP-LI, and about 54%, 58% and 59%, respectively, showed CGRP-LI. Some of the SP-or CGRP-LI TG neurons that were double labelled with FB and DY were assumed to mediate pain signals to both the Vp and the spinal trigeminal nucleus (Vo, Vi and/or Vc) by way of axon collaterals.Yun-Qing Li is on leave from the Department of Anatomy, The Fourth Military Medical University, Xian, People's Republic of China     

摘除颈上神经节对成年大鼠海马基质金属蛋白酶9和水通道蛋白9 表达的影响

目的 观察摘除颈上神经节（SCG）对成年大鼠海马基质金属蛋白酶9（MMP9）和水通道蛋白9（AQP9）表达的影响,探索交感神经对脑组织的调节作用及机制。 方法 40只成年健康雄性Wistar大鼠分为对照组和手术组,手术组大鼠摘除双侧SCG;用免疫组织化学法对海马区MMP9及AQP9蛋白的表达进行定位,Western blotting技术对海马区MMP9及AQP9蛋白的表达进行定量分析,RT PCR技术测定海马区MMP9 mRNA及AQP9 mRNA的表达变化。 结果 MMP9免疫阳性反应产物表达于神经元和神经胶质细胞,手术组海马区 MMP9的表达明显强于对照组,CA1区和CA3 区的阳性神经元在锥体细胞层散在分布,齿状回（DG）区的强阳性细胞主要位于颗粒细胞层;手术组海马MMP9蛋白表达和MMP9 mRNA表达水平明显升高,和对照组相比差异极显著（P<0.01 )。AQP9免疫阳性反应产物在神经元、神经胶质细胞和血管均有表达,手术组 AQP9的表达明显强于对照组,DG区的强阳性细胞主要位于颗粒细胞下层的新生细胞,且室管膜细胞中也有AQP9的高表达;手术组AQP9蛋白表达和AQP9 mRNA表达水平均明显增强,与对照组相比差异极显著（P<0.01）。 结论 摘除成年大鼠SCG 15d 后,海马MMP9、AQP9的表达明显上调,表明脑部去交感所引起的脑供血的改变会对海马多个因子的表达产生影响而发挥调节作用。