NEURAL PATHWAYS OF TRIGEMINAL PROPRIOCEPTIVE AFFERENTS COORDINATE ORAL MOTOR BEHAVIORS / 神经解剖学杂志

Neural pathways and synaptic connections from the trigeminal mesencephalic nucleus (Vme) neurons to the cranial motor nuclei were studied in the rat using double labelling methodologies of intracellular Neurobiotin staining combined with retrograde horseradish peroxidase (HRP) transport, anterograde biotinylated dextran amine (BDA) tracing combined with retrograde HRP transport, and a dual fluorescent labelling of BDA anterograde combined tracing with Cholera Toxin B (CTB) retrograde transport. Direct projections and synapses were demonstrated from Vme neuronal boutons to motoneurons (MNs) of the trigeminal motor nucleus (Vmo), the hypoglossal nucleus (Ⅻ) and the ambiguus nucleus (Amb). Indirect projections and pathways from Vme neurons to the cranial motor nuclei including Vmo, Ⅻ, the facial nucleus (Ⅶ) and the cervical spinal cord (C1～5) were seen to relay on their premotor neurons. The premotor neurons of above cranial motor nuclei were overlapped in bilateral premotor neuronal pool including the parvocellular reticular formation (PCRt) and its alpha division (PCRtA), the dorsomedial part of the spinal trigeminal nucleus oralis (Vodm), and interpolaris (Vidm), the medullary reticular nucleus dorsal division (MdD), the supratrigeminal region (Vsup) and the dorsomedial part of the principal trigeminal sensory nucleus (Vpdm).Synapses between Vme neuronal boutons and Vmo and Ⅻ MNs and Ⅻ premotor neurons were predominantly asymmetric.There were four types of synaptic organizations, i.e. synaptic convergence; synaptic divergence presynaptic inhibition and afferent feedforward inhibition seen between Vme boutons and Vmno, Ⅻ MNs and between Vme boutons and Ⅻ premotor neurons.The results of present studies have demonstrated direct pathways from the trigeminal proprioceptive afferents to Vmo, Ⅻ and Amb MNs, and indirect pathways from the trigeminal proprioceptive afferents to bilateral Vmno, Ⅻ, Ⅶ and C1～s via their premotor neurons. It provides neuroanatomical network to elucidate trigeminal proprioceptive afferents coordinate oral motor behaviors.

PARVALBUMIN-EXPRESSING NEURONS ON THE CENTRAL PATHWAY OF THE TRIGEMINAL PROPRIOCEPTIVE SENSATION OF THE RAT: A DOUBLE LABELING STUDY / 神经解剖学杂志

Previous studies showed that the Vodm-LRF-including the dorsomedial part of the subnucleus oralis of the spinal trigeminal nucleus and its adjacent lateral reticular formation--contained the second-order neurons on the central pathway of the trigeminal proprioceptive sensation of the rat and the "zone-shaped area"-including the caudolateral part of the supratrigeminal nucleus (Vsup-CL). The dorsomedial part of principal sensory trigeminal nucleus (Vpdm) and two newly found nuclei: the areaventral to the motor trigeminal nucleus (AVM) and the area dorsal to the superior olivary nucleus (ADO)-contained the third order neurons of this pathway. Parvalbumin (PV) is one of the calcium-binding proteins, In this pathway, many PV-like immunoreactive (PV-LI) neurons were observed in Vodm LRF and the "zone-shaped arena", hut there has been no reports so far regarding whether these PV-LI neurons are projection neurons responsible for the transmission of proprioceptive information or the interneurons serving the modulatory function, in the present study, our aim was to solve the problem by a double labeling study by using retrograde tracing method combined with immunofluorescence histochemistry. The results showed that: (1) following the unilateral Fluoro-Gold (FG) injections into the ventral posteromedial nucleus (VPM) of the thalamus and the separated parts of the "zone-shaped area", viz, Vpdm, ADO and AVM, many FG-labeled neurons were always found contralaterally in the "zone-shaped area" and ipsilaterally in the Vodm-LRF, respectively; (2) in either the "zone-shaped area" or the Vodm-LRF, a substantial number of the FG retrogradely labeled neurons showed PV-LI. In the Vsup-CL, Vpdm, AVM and ADO, about 57%, 55%, 11% and 4% of the neurons projecting to the VPM of the thalamus showed pV-LI, respectively. Of the total population of PV-LI neurons in the Vsup-CL, Vpdm. AVM and ADO, about 23%, 79%, 53% and 16% were labeled by FG, respectively. Most of these PV/FG double-labeled neurons were medium- to small-sized, round, piriform or irregular in shape. On the other hand, in the Vodm-LRF, approximately 33%, 34% and 50% of the neurons which projected to the Vpdm, AVM and ADO expressed PV-LI, respectively. The percentage of PV/FG double-labeled neurons to the total number of the PV-LI neurons in Vpdm, AVM or ADO were 26%, 17% or 11%, respectively, The present results indicated that PV might play an important role in the transmission of the trigeminal proprioceptive information of the rat from Vndm-LRF to the contralateral VPM of the thalamus through the "zone-shaped area".

The Effect of Coriaria Lactone on NMDA Receptor Mediated Currents in Rat Hippocampal CAI Neurons / 华中科技大学学报（医学）（英德文版）

To investigate the exact mechanism of epileptogenesis induced by coriaria lactone (CL), the effect of CL on NMDA receptor mediated current (Iasp) in rat hippocampal CAI neurons was investigated by using nystatin perforated whole-cell patch clamp. 10-6-10-4 mol/L Asp acted on NMDA receptors and elicited an inward current (Iasp) at a holding potential (VH) of -40mV in presence of 10-6 mol/L glycine and absence of Mg2+ extracellularly. CL enhanced NMDA receptor mediated current induced by Asp, but had no effect on threshold concentration, EC50,Hill coefficient as well as maximal-effect concentration and reversal potential of Iasp. The effect had no relationship with holding potential. These results showed that CL could enhance NMDA receptor mediated current to increase [Ca2+]I of neurons by acting on Gly site, thereby inducing epilepsy.

The Effect of Coriaria Lactone on NMDA Receptor Mediated Currents in Rat Hippocampal CAI Neurons / 华中科技大学学报（医学）（英德文版）

To investigate the exact mechanism of epileptogenesis induced by coriaria lactone (CL), the effect of CL on NMDA receptor mediated current (Iasp) in rat hippocampal CAI neurons was investigated by using nystatin perforated whole-cell patch clamp. 10-6-10-4 mol/L Asp acted on NMDA receptors and elicited an inward current (Iasp) at a holding potential (VH) of -40mV in presence of 10-6 mol/L glycine and absence of Mg2+ extracellularly. CL enhanced NMDA receptor mediated current induced by Asp, but had no effect on threshold concentration, EC50,Hill coefficient as well as maximal-effect concentration and reversal potential of Iasp. The effect had no relationship with holding potential. These results showed that CL could enhance NMDA receptor mediated current to increase [Ca2+]I of neurons by acting on Gly site, thereby inducing epilepsy.

Intracellular modulation and its mechanisms of GABA_A receptors / 中国药理学通报

In addition to modulation by a variety of structurally diverse agents that act allosteri-cally via distinct binding sites on the receptor complexes , there is another outstanding characteristic of the GABAA receptors: they are modulated by multiple endogenous agents. Well known examples include Ca2+ , adenosine triphosphate (ATP) , protein kinase A (PKA), protein kinase C(PKC), ty-ros ine kinase (TK) and calmodulin-dependent protein kinase II (CaMK II ). Intracellular modulation of GABAA receptor function may have profound effects on the control of neuronal excitation.

THE CYTOARCHITECTURE OF DORSAL COMMISSURE NUCLEUS OF THE SACRAL SPINAL CORD IN CAT / 解剖学报

The Nissl and Golgi staining methods and electron microscopy were u(?)o investigate the architecture of dorsal commissure nucleus (DCN) of the sacral spinal cord in cat. A morphologically specific nucleus could be identified in the medial part of the lamina Ⅵ of dorsal horn. The nucleus located beside the dorsal funiculus at the lumbar level and gradually moved toward the midline of the dorsal gray commissure in the ventromedial direction as the dorsal gray commissure enlarged at the segments S_(1-2) and two ellipsoid nuclei was formed at the two sides of the midline. A large triangular nucleus was gradually formed by fusion of the two nuclei at S_3-Co_1. Golgi stain positive neurons could be classified into three types: (1) small-triangular neurons (60%); (2) fusiform neurons (30%); (3) oval and irregular neurons (10%). The cell organells of most neurons were plentiful. The cell nucleus was irregular and often with deep invaginations. A large number of free ribosomes and saccules could be found in the canals formed by the nuclear invagination. There were axo-dentritic, axo-axonic, axo-somatic synaptic contacts in the DCN with percentages of 89%, 6%, and 5% respectively. The serial synapse, axo-spinous synapse and crest synapses could also be found.

THE STRUCTURE OF THE SUBNUCLEI OF INTERPEDUNCULAR NUCLEUS IN HUMAN NEONATAL BRAIN AND THEIR DISTRIBUTION OF SUBSTANCE P-, LEUENKEPHALIN-, AND SEROTONIN (5-HT)-LIKE IMMUNOREACTIVE ELEMENTS / 解剖学报

Nissl stain and immunocytochemical methods were used to observe the structure of the subnuclei of interpeduncular nucleus in human neonatal brain and their localization of substance P-, leu enkephalin-, and serotonin (5-HT)-like immunoreactive elements. It was detected that the human neonatal interpeduncular nucleus could be divided into five subnuclei, including: the dorsal, dorsolateral, lateral, central, and intermediate subnuclei. The immunocytochemical results showed that the substance P-containing cell bodies and fibers or terminals were distributed chiefly in the dorsolateral, lateral subnuclei and the ventral part of the intermediate subnucleus; the enkephalin-containing cell bodies and fibers or terminals were concentrated in the central subnucleus; and meanwhile the serotonin-containing cell bodies and fibers or terminals were found mainly in the dorsal subnucleus.

THE CENTRAL CONNECTIONS AND FUNCTIONAL CONSIDERATIONS OF THE DORSAL COMMISSURAL NUCLEUS OF THE RAT——A HRP METHOD STUDY / 解剖学报

HRP solution was injected into the dorsal commissural nucleus (DCN) of segment L_6 or S_1 of the spinal cord and laterodorsal tegmental area(TLD)——take the Barrington's nucleus as its center and lateral parabrachial nucleus (PBL) of the rostral pons in different individuals of the rats. After HRP was injected into the DCN, labelled neurons and dense terminals were found in Barrington's nucleus, and labelled terminals appeared in the PBL. When the unilateral TLD was injected the labelled cells and terminals were found in the DCN and bilateral intermediate zone (IM), and formed a band of labelled neurons and terminals. When the PBL was injected the labelled neurons were observed in the DCN and bilateral IM. A few labelled neurons were found in lamina Ⅰ in the latter two experimental groups.Based on the present and previous studies, the authors got the following understandings:1. Morphylogically, the present study for the first time demonstrated that, the micturition reflex arch through the pontine consists of following parts: the primary afferent neurons of the bladder→secondary relay neurons of DCN→Barrington's nucleus→IM (mainly IML) parasympathetic preganglionic neurons→parasympathetic postganglionic neurons.2. According to the present and previous researches, the authors conjecture that, the secondary fibers of visceral sensation of the pelvic organs originate from the neurons of DCN, IM and lamina I and project into the PBL.3. According to the facts mentioned above, we presume that the DCN and bilateral IM constitute a complex and named it the 'visceral field', and which is closely associated with the pelvic organs. This field has widespread connections with the peripheral efferent and afferent nerves. On the other hand, i t contains a lot of relay neurons projecting into Barrington's nucleus and PBL and receives the terminals of descending fibers of the neurons of the Barrington's nucleus. The descending fibers also project into the Onuf's nucleus.In addition, the present study disscussed the complicated functions of the DCN systematically.

THE MORPHOLOGY AND DISTRIBUTION OF THE CHOLINERGIC NEURONAL ELEMENTS IN THE SACRAL AND COCCYGEAL SPINAL CORD OF THE CAT: AN IMMUNOHISTO-CHEMICAL STUDY WITH A MONOCLONAL ANTIBODY TO CHOLINE ACETYL-TRANSFERASE TRANSFERASE / 解剖学报

The morphological characteristies and distribution of the choline acetyltransferase (ChAT)-like immunoreactive neuronal elements in the sacral and coccygeal spinal cord of the cat were studied by avidin-biotin combined immunohistochemical technique. The results were as follows:1. The ChAT-positive neuronsIn the ventral horn, ChAT-positive motoneurons were located in the motor columns. These neurons can be divided into three types: the large multipolar neurons, the medium-sized multipolar neurons and the small motoneurons. The color of anti-ChAT reaction product in the large and medium-sized motoneurons varied from light to moderate brown, but the small motoneurons were heavily stained.In the intermediate zone, three groups of ChAT-positive parasympathetic preganglionic neurons were observed in 3 areas: the intermediolateral nucleus (IL) in the lateral part of lamina Ⅶ, the intermediomedial nucleus (IM) dorsal-lateral to the central canal, the intercalated nucleus (IC) looated between IL and IM. The somata of these neurons were round, oval, and fusiform in shape. In the lamina Ⅶ, there were some prominent ChAT medium-sized multipolar neurons named partition cells, scattered among the extended fibers of the parasympathetic preganglionic cells. In the vicinity of the central canal could be observed small CHATpositive cells.In the ventral part of the dorsal commissural nucleus region, a number of ChAT-positive cells were present. They were round, oval and fusiform in shape and small in size (averaging 11.91?m?17.38?m). Occasionally, they were observed in the dorsal part.In addition, some of the ChAT-positive neurons were scattered in laminae Ⅲ-Ⅴ.2. The ChAT-positive fibers and terminals.The ChAT-positive punctate structures were observed throughout the sacral and coccygeal spinal cord resembling terminal branch and terminals. The density of the distribution of the punctate structures was arranged, from high to low, in the following order: the ventral horn, intermediate zone, central gray matter and dorsal commissural nucleus region, and the dorsal horn. In the dorsal horn, many of these punctate structures Were concentrated in two laminae, the major one being lamina Ⅲ and a minor one lamina Ⅰ. But in lamina Ⅱ, they were rare. In the ventral horn such punctate structures were often closely contacted with large and medium-sized ChAT-positive motoneuronal somata and dendrites. Some axonal terminal branch with varicosities closely surrounded a somata and bases of dendrites, and formed contacts with the same somata and its dendrites. In the intermediate zone, there were many transverse fibers associated among the parasympathetic preganglionic nuclei.

THE CYTOARCHITECTONIC STRUCTURE OF LAMINA V OF MEDULLARY DORSAL HORN (TRIGEMINAL NUCLEUS CAUDALIS) IN THE CAT / 解剖学报

Using Nissl method, Kluver and Barrera method and rapid Golgi method, we found that there were large, medium and small-sized neurons in lamina V of medullary dorsal horn Of the cat, the medium-sized neurons were most numerous and the large-sized neurons were least in number. According to the dendritic branching pattern and the number of spines, the lamina Ⅴ neurons could be divided into two categories——the radiate neuron and bushy neuron. The former contained three subcategories: pyramidal, polygonal and bipolar neurons. Spiny and smooth types were found in pyramidal and polygonal neurons. Considering with the results of neurophysiologic research and intracellular injection of HRP by others, we presume that different types of neurons in lamina Ⅴ might also differ functionally. In addition, according to the results of transganglionic transport of HRP from the peripheral and retrograde transport of HRP from the thalamus, it was assumed that some neurons in lamina V received messages from the primary afferent in lamina Ⅴ, Ⅳ, and Ⅲ, and thence, transmitted them to the thalamus.

THE INNERVATION OF THE ANTERIOR WALL OF THE STOMACH IN THE RABBIT. A STUDY WITH THE HRP METHOD / 解剖学报

10% and 20% HRP aqueous solution was injected into the anterior wall of the stomach of rabbit, and both the afferent and efferent nerve connections of this region were examined.1. Large number of labeled cells appeared in the dorsal motor nucleus of the vagus nerve (dmnX) on both sides throughout its whole length, except the very rostral and caudal ends of it. The labeled cells were more numerous in the middle part of the nucleus at levels above and below the obex. The distribution of the labeled cells showed certain localization characteristics. Those in the caudal part of the nucleus occupied the medial portion, those in the levels around the obex distributed widely in the nucleus, while in the rostral part they were smaller in number and showed no definite localization.2. In the area between the dorsomedial border of the dmnX and the area pos- trema, the so-called area subpostrema, some disseminated labeled cells, the form of which was similar to that the labeled cells in the dmnX, were also observed.3. Numerous labeled cells appeared in the nodose ganglia on both sides, the number of which was several times more than that in the spinal ganglia, indicating that the afferent connection of the stomach via the vagus nerve predominated over that via the sympathetic nerve. The small-sized labeled cells in the ganglion, however, appeared up to more than 40% of all the labeled cells in it, the functional significance of them, as well as the relation between them and the labeled small cells in the spinal ganglia, is worth further investigation.4. The labeled neurons appeared in the spinal ganglia from Th_3 to L_3, most of them were in Th_3 to Th_(10), showing that the afferents of the stomach via the sympathetic system were diffusely arranged and at the same time concentrated in certain segments.5. Our observations confirmed that the stomach is innervated by elements of bilateral origin. In the vagus system the afferent and efferent neurons appeared almost equally in both dmnX and both nodose ganglia. And in the sympathetic system, the afferent neurons on the left side were 1 to 2 times more than those on the right, i. e., the left side is predominant.

THE LOCALIZATION OF PERIPHERAL EFFERENT AND ASCENDING PROJECTION NEURONS IN THE LUMBOSACRAL "VISCERAL FIELD" OF THE RAT——FLUORO-GOLD AND HRP TRACING STUDY / 解剖学报

In the present study, the fluoro-gold(FG) and horseradish peroxidase(HRP) combined tracing method was used to investigate the localization of parasympathetic preganglionic neurons and ascending projection neurons in lumbosacral spinal cord of the rat. FG was injected into the lateral parabrachial nucleus(PBL) or into Barrington's nucleus on one side, and HRP was applied to the contralateral pelvic nerve. The retrogradely FG-labeled neurons were found in bilateral "visceral field" at segments L_5-S_2, and the majority of them were concentrated in the intermediolateral nucleus (IML), and the dorsal commissural nucleus (DCN). In addition to these areas, some labeled neurons were also observed in bilateral lamina I and lateral spinal nucleus (LSN). The parasympathetic preganglionic neurons labeled with HRP were seen in the IML at segments L_6-S_1, occasionally appeared in the intercalated nucleus. In the IML area, HRP-labeled parasympathetic preganglionic neurons were located in its ventral part, however, the localization of FG-labeled neurons projected to the PBL and Barrington's nucleus were mainly found in the dorsal and dorsomedial part of the IML, and a few FG-labeled cells were scattered among HRP-labeled cells. Based on the present and other investigations, the nomenclature, organization and function of the IML and the composition of the LSN were discussed.

THE INDIRECT PATHWAY OF THE SOMATIC AFFERENT ELEMENTS FROM TRIGEMINAL NERVE TO NUCLEUS TRACTUS SOLITARII——A LIGHT AND ELECTRON MICROSCOPIC HRP TRANSGANGLIONIC AND RETROGRADE TRACING STUDY / 解剖学报

The indirect pathway of the somatic afferent elements from trigeminal nerve (TGN) to nucleus tractus solitarii (NTS) was studied with the light and electron microscopic HRP transganglionic and retrograde tracing. After HRP was injected into NTS at the level of obex, the retrogradely labeled cells were mainly found in the interstitial nucleus buried in the spinal tract of TGN along caudal subnucleus. The interstitial nucleus was also the terminating area of the primary afferent fibers of lingual and inferior orbital nerves. Under electron microscope, it was found that the primary afferent terminals of lingual and inferior orbital nerves formed synapses on the dendrites of neurons in the interstitial nucleus. Moreover, in cellular architecture, the interstitial nucleus and the superficial laminae of the caudal nucleus of TGN were similar and continuous with each other. Hence, the pathway from the TGN to NTS via the interstitial nucleus is consisted of two neurons and the sensations transmitted through this pathway may be considered to be somatic. It is presumed that this pathway composed of two neurons might modulate the visceral afferent function in NTS when certain points in the skin area innervated by TGN were acupunctured.

THE PROJECTIONS OF THE NUCLEUS RAPHE DORSALIS TO THE SUBNUCLEUS CAUDALIS OF THE TRIGEMINAL NERVE IN THE CAT / 解剖学报

HRP solution was injected into the right subnucleus caudalis of the trigeminal nerve in the cat, and the labeled cells in the nucleus raphe dorsalis of six cases were examined and analyzed. The labeled cells appeared more in the middle portion and its rostral adjacent parts of the nucleus raphe dorsalis, decreased in number rostrally and caudally, and were entirely absont in the caudal end of the nucleus. In the ventral part and the ventral areas of the lateral parts of the nucleus labeled cells were more than in the other areas of the nucleus, no difference was found between the two sides. In the dorsal part and the dorsal regions of the lateral parts of the nucleus only a few labeled cells were seen. The labeled cells varied in forms, but in the ventral part and the ventral regions of the lateral parts they were mainly fusiform in shape. In addition, in nucleus raphe magnus, nucleus raphe pallidus, and nucleus raphe obscurus, small numbers of neurones were labeled as well.As the nucleus raphe magnus takes part in the inhibition of the response to noxious stimuli in the spinal dorsal horn, and as both the nucleus raphe magnus and nucleus raphe dorsalis belong to the more developed raphe nuclei and contain more 5-HT neurones, it seems that there might be somatotopic relations between the nucleus raphe dorsalis which projects mainly to subnucleus caudalis and the nucleus raphe magnus which projects mainly to the spinal dorsal horn.

DISTRIBUTION OF THE DICHOTOMIZING BRANCHES OF PERIPHERAL PROCESSES OF CAUDAL LUMBAR DORSAL ROOT GANGLION NEURONS IN THE RAT——A DOUBLE FLUORESCENCE LABELLING STUDY / 解剖学报

The technique of double labelling with fluorescent tracers(FB-NY,PI-Bb)has.been used in the following three groups of experiments:1.in 5 rats,one fluorescenttracer was injected into the tibial nerve and the other was injected into the peronealnerve;2.in 14 rats,one fluorescent tracer was injected into the sural cutaneousnerve and the other was injected into the branches to the soleus and gastrocnemiusmuscles;3.in 13 rats,one tracer was injected into the tibial nerve and the otherinto the bladder wall.The sections of the L_(3-6),S_(1-3) dorsal root ganglion were stu-died with a olympus fluorescence microscope using UG-1 excitation filter system.In the first and second groups,double labelled neurons were observed in L_(4-6) dorsalroot ganglion.But in the third group,the double labelled neurons were found onlyin the L_6 segment.The type of the double labelled neurons was mainly small-sized(33.1%)and small-medium sized(40.9%).The findings indicated that,the primary afferent fibers branched towards theperiphery and supplied,with different branches,either two somatic areas or skinand deep structures,or,especially,visceral and somatic sensory fields.This resultsuggests that the peripheral dichotomization of these dorsal root ganglion cells mightconverge sensory inputs from the somatic(tibial nerve)and the visceral(bladderwall)fields and thus provides one of the structural basis for the referred pain andthe neuronal mechanism of acupunctural therapy by which stimulation of somaticstructures could regulate the activities of visceral organs.

CONNECTIONS BETWEEN THE PREPRODYNORPHIN-,PREPROEN- KEPHALIN-LIKE IMMUNOREACTIVE TERMINALS AND COEXISTENT NEURONS OF THE PHOSPHATE ACTIVATED GLUTAMINASE AND PARVALBUMIN IN THE MESENCEPHALIC TRIGEMINAL NUCLEUS OF THE RAT / 解剖学报

Objective To observe the co-localization of phosphate activated glutaminase(PAG) and parvalbumin(PV) in neurons,and the connections between preprodynorphin-like immunoreactive(PPD-LI) or preproenkephalin(PPE)-LI terminals and coexistent neurons of PAG-LI and PV-LI in the mesencephalic trigeminal nucleus(Vme) of the rat. Methods In the present study,the immunofluorescence histochemical double-staining and triple-staining technique were used.The staining results were observed under a confocal laser scanning microscope. Results Many neuronal cell bodies through the whole rostrocaudal extent of Vme showed PAG-LI and PV-LI.The majority of them were large pseudounipolar neurons.A considerable number of PV-LI neurons expressed PAG-LI,cell counts showed that more than 95% of PV-I neurons were immunostained with PAG-LI.Confocal laser scanning microscope further revealed that axonal varicosities with PPD-LI or PPE-LI were found to make close contact with neuronal cell bodies of Vme showed both PAG-LI and PV-LI. Conclusion The present results indicated that the glutamate and PV are involved in the transmission of the trigeminal proprioceptive sensory singals from the Vme to the higher centers,simultaneously,dynorphin-and enkephalin-immuoreactive terminals may also exert modulatory influence on the primary afferent cell bodies of the Vme.;

THE SECONDARY AFFERENT PATHWAY OF PELVIC VISCERAL SENSATION / 解剖学报

2?l 10% ricin were injected into the pelvic nerve of cats. After 3～5 survival days 20% HRP solution was injected into the ipsilateral lateral parabrachial nucleus, 2～3 days later the animals were perfused with paraformaldehyde and glutaraldehyde, the brain and spinal cord were removed and processed for light and electron microscopy. It was confirmed that the primary afferent terminals (degenerated) of pelvic nerve formed axo-dendritic and axo-somatic synapses with the retrograde labelled neurons projected to the lateral parabrachial nucleus which were located in the dorsal commissure nucleus (DCN), intermediolateral nucleus (IML) and lamina Ⅰ of sacral spinal cord. Hence, the secondary afferent pathway of pelvic visceral sensation, as. indicated at the ultrastructural level, might originate from DCN, IML and lamina Ⅰ of sacral spinal cord and project to the lateral parabrachial nucleus.

ULTRASTRUCTURE OF THE DESCENDING RUBRAL FIBERS IN LAMINA V OF THE CAT TRIGEMINAL SUBNUCLEUS CAUDALIS——HRP LABELING AND DEGENERATION STUDY / 解剖学报

After a injection of kainic acid or WGA-HRP into the red nucleus, the degenerated or HRP labeled terminals in lamina V of the contralateral trigeminal subnucleus caudalis (Vc) were examined electron microscopically. It was found that the degenerated and HRP labeled terminals contained vesicles of spherical or mixed type, and formed symmetrical synapses with medium- or small-sized dendrites. These findings suggested that the descending rubral fibers might be inhibitory in regulating the activity of the neurons, and supposed to be sensory in nature. Thus the red nucleus might play certain role in modulation of the oro-facial somatosensory transmission (including pain) in lamina V of Vc, besides the rubrospinal influence on the involuntary motor functions of the spinal anterior horn. The technique for tracing neural connections with electron microscope was discussed as well.

ULTRASTRUCTURAL EVIDENCE OF SEROTONINERGIC INNERVATION OF THE SECONDORDER NEURONS ON THE CENTRAL PATHWAY OF THE TRIGEMINAL PROPRIOCEPTION OF THE RAT / 解剖学报

Objective To investigate whether the serotonin(5\|HT)\|like immunoreactive axons synapse upon the second\|order neurons on the central pathway of the trigeminal proprioception in the rat. Methods Electron microscopic double\|labeling of retrograde tract\|tracing technique combined with immunohistochemistry. Results Following the injection of wheat germ agglutinin\|horseradish peroxidase (WGA\|HRP) into the dorsomedial part of the principal sensory trigeminal nucleus(Vpdm) of the rat and the immunostaining for 5\|HT, there were neurons retrogradely labeled by WGA\|HRP and axon terminals with 5\|HT\|like immunoreactivity(5\|HT\|LI) in the dorsomedial part of the subnucleus oralis of the spinal trigeminal nucleus and its adjacent lateral reticular formation(Vodm\|LRF).At the electron microscopic level,the 5\|HT\|immunostained axonal profiles were observed to make synaptic contacts with the WGA\|HRP\|labeled neurons.Both the axon\|somatic and axon\|dendritic synapses were found.These synapses were mainly of symmetric type although the asymmetric ones were also seen.Conclusion\ The present results provided a morphologic basis for the serotoninergic terminals which might be involved in the regulatory effect for the trigeminal proprioceptive information transmission.\;[