Effect of periapical inflammation on calcium binding proteins and ERK in the trigeminal nucleus / Efecto de la inflamación periapical sobre las proteínas fijadoras de calcio y ERK en el núcleo trigeminal

Peripheral inflammation induces plastic changes in neurons and glia which are regulated by free calcium and calcium binding proteins (CaBP). One of the mechanisms associated with the regulation of intracellular calcium is linked to ERK (Extracellular Signal-Regulated Kinase) and its phosphorylated condition (pERK). ERK phosphorylation is important for intracellular signal transduction and participates in regulating neuroplasticity and inflammatory responses. The aim of this study is to analyse the expression of two CaBPs and pERK in astrocytes and neurons in rat trigeminal subnucleus caudalis (Vc) after experimental periapical inflammation on the left mandibular first molar. At seven days post-treatment, the periapical inflammatory stimulus induces an increase in pERK expression both in S100b positive astrocytes and Calbindin D28k positive neurons, in the ipsilateral Vc with respect to the contralateral side and control group. pERK was observed coexpressing with S100b in astrocytes and in fusiform Calbindin D28k neurons in lamina I. These results could indicate that neural plasticity and pain sensitization could be maintained by ERK activation in projection neurons at 7 days after the periapical inflammation.

La inflamación periférica induce cambios plásticos en las neuronas y en la glía, los cuales están regulados por el calcio libre y las proteínas fijadoras calcio (CaBP). Uno de los mecanismos asociados con la regulación del calcio intrace-lular está vinculado con la fosforilación de la pro teína quinasa ERK. Asimismo, ERK fosforilado es importante para la trans-ducción de señales intracelulares y participa en la regulación de la neuroplasticidad y las respuestas inflamatorias. El objetivo de este estudio es analizar la expresión de dos CaBPs y pERK en astrocitos y neuronas del subnúcleo caudal del trigémino (Vc) después de una inflamación periapical experimental en el primer molar inferior izquierdo en ratas. A los siete días posteriores al tratamiento, el estímulo inflamatorio periapical induce un aumento en la expresión de pERK, en el número de astrocitos positivos para la proteína marcadora astroglial S100b y en neuronas positivas para Calbindina D28k, en el Vc ipsilateral respecto del lado contralateral y el grupo de control. Además, se observó coexpresión de pERK tanto en astrocitos S100b positivos, como en neuronas fusiformes Calbindin D28k positivas, de la lámina I. Estas observaciones podrían indicar que la neuroplasticidad y la sensibilización al dolor podrían mantenerse mediante la activación de ERK en las neuronas de proyección a los 7 días de la inflamación periapical.

Role of neuron and non-neuronal cell communication in persistent orofacial pain

It is well known that trigeminal nerve injury causes hyperexcitability in trigeminal ganglion neurons, which become sensitized. Long after trigeminal nerve damage, trigeminal spinal subnucleus caudalis and upper cervical spinal cord (C1/C2) nociceptive neurons become hyperactive and are sensitized, resulting in persistent orofacial pain. Communication between neurons and non-neuronal cells is believed to be involved in these mechanisms. In this article, the authors highlight several lines of evidence that neuron-glial cell and neuron macrophage communication have essential roles in persistent orofacial pain mechanisms associated with trigeminal nerve injury and/or orofacial inflammation.

Effect of carbamazepine and gabapentin on excitability in the trigeminal subnucleus caudalis of neonatal rats using a voltage-sensitive dye imaging technique

BACKGROUND: The antiepileptic drugs carbamazepine and gabapentin are effective in treating neuropathic pain and trigeminal neuralgia. In the present study, to analyze the effects of carbamazepine and gabapentin on neuronal excitation in the spinal trigeminal subnucleus caudalis (Sp5c) in the medulla oblongata, we recorded temporal changes in nociceptive afferent activity in the Sp5c of trigeminal nerve-attached brainstem slices of neonatal rats using a voltage-sensitive dye imaging technique. RESULTS: Electrical stimulation of the trigeminal nerve rootlet evoked changes in the fluorescence intensity of dye in the Sp5c. The optical signals were composed of two phases, a fast component with a sharp peak followed by a long-lasting component with a period of more than 500 ms. This evoked excitation was not influenced by administration of carbamazepine (10, 100 and 1,000 µM) or gabapentin (1 and 10 µM), but was increased by administration of 100 µM gabapentin. This evoked excitation was increased further in low Mg²+ (0.8 mM) conditions, and this effect of low Mg²+ concentration was antagonized by 30 µM DL-2-amino-5-phosphonopentanoic acid (AP5), a N-methyl-D-as-partate (NMDA) receptor blocker. The increased excitation in low Mg²+ conditions was also antagonized by carbamazepine (1,000 µM) and gabapentin (100 µM). CONCLUSION: Carbamazepine and gabapentin did not decrease electrically evoked excitation in the Sp5c in control conditions. Further excitation in low Mg²+ conditions was antagonized by the NMDA receptor blocker AP5. Carbamazepine and gabapentin had similar effects to AP5 on evoked excitation in the Sp5c in low Mg²+ conditions. Thus, we concluded that carbamazepine and gabapentin may act by blocking NMDA receptors in the Sp5c, which contributes to its anti-hypersensitivity in neuropathic pain.

Changes of the level of phosphorelated ERK1/2 in the spinal trigeminal nucleus of migraine model rats / 中华行为医学与脑科学杂志

Objective To explore the role of ERK1/2 in the central pathogenesis of migraine.Methods Healthy adult male SD rats were randomly divided into five groups:normal group (group C),sham operation group(group C),migraine model group(group M),DMSO group (group D)and PD-98059group (PD group),with 12 rats in each group.The extracellular discharge frequency in the spinal trigeminal nucleus was recorded and ERK1/2 phosphorylation was tested.Results (1) The percentage of extracellular discharge frequency change:Two hours after treatment,the percentage of discharge frequency change was (325.9±47.32)％.The percentage of extracellula discharge frequency change in group M (325.9±47.3)％ was higher than that in group N (100.0± 0.0) ％ and group C(107.3± 16.4)％.There was no significant difference in the percentage of discharge frequency change between group D(319.3±42.5) ％ and group M (325.9±47.3) ％.The percentage of discharge frequency change in group PD(218.5±31.7)％ was lower than that in group M(325.9±47.3)％ and group D(319.3± 42.5)％.(2) ERK1/2 phosphorylation:the ERK1/2 phosphorylation in group M and group D was higher than that in group N and group C.There was no significant difference in ERK1/2 phosphorylation between group D and group M.The ERK1/2 phosphorylation in group PD was lower than the other four groups.Conclusion During the process of central sensitization to migraine,neuronal excitability and ERK1/2 phosphorylation were increased.ERK1/2 inhibitor (PD98059) reduced ERK1/2 phosphorylation and neuronal excitability.These indicated that ERK1/2 may play a role in central sensitization of migraine in rats.

Effect of protein kinase C inhibitor on the level of phosphralated extracellular regulated protein kinases in the spinal trigeminal nucleus of migraine model rats / 中华行为医学与脑科学杂志

Objective To explore the effect of protein kinase C inhibitor on the level of phosphralated extracellular regulated protein kinases in the spinal trigeminal nucleus of migraine model rats.Methods Healthy adult male SD rats were randomly divided into four groups:normal group (group C),sham operation group (group C),migraine model group(group M),and H-7group(H-7group),with 18 rats in each group.Dural blood flow and the extracellular discharge frequency in the spinal trigeminal nucleus was recorded.ERK1/2 phosphorylation was tested.Results (1) Dural blood flow:compared with group C((3.8± 1.0)％),the dural blood flow in M group ((78.0±4.2) ％)increased obviously(P＜0.01) ; compared with M group((78.0±4.2)％),the dural blood flow in H-7 group((-24.8±4.9) ％) decreased obviously(P＜0.01).(2) The percentage of extracellular discharge frequency change:two hours after treatment,the percentage of extracellula discharge frequency change in group M ((325.9 ±47.3)％)was higher than that in group C((107.3±16.4)％).The percentage of discharge frequency change in group H-7((136.0±26.5)％) was lower than that in group M((325.9±47.3)％).There was no significant difference in the percentage of discharge frequency change between group H-7((136.0±26.5) ％) and group C((107.3 ± 16.4)％).(2) ERK1/2 phosphorylation:the ERK1/2 phosphorylation in group M was higher than that in group C.The ERK1/2 phosphorylation in group H-7 was lower than than that in group C and group M.Conclusion ERK1/2 is a downstream PKC signal path and PKC may have indirect activation of ERK1/2.

The blink reflex test does not show abnormalities in a large group of patients with chronic migraine / O teste do reflexo do piscamento nao mostra alteracoes em um grande grupo de pacientes com enxaqueca cronica

The blink reflex – a simple, non-invasive and inexpensive test – may be indicative of lesions or dysfunctions of the brainstem, and particularly assesses the trigeminal-facial arch. Results from alterations of the blink reflex in patients with headaches have provided controversial data. Method Registration of the waves R1 and R2 (ipsilateral to the stimulus) and R2c (contralateral to the stimulus) by electroneuromyography. Results A large number of controls (n=160) and patients with chronic migraine (n=160) were studied. No significant differences were observed between the two groups. Conclusion It is possible that this relatively simple and primitive reflex is not affected unless there is significant damage to the brainstem. .

O reflexo do piscamento é um teste simples, não invasivo de baixo custo que pode direcionar o raciocínio para lesões ou disfunções do traonco cerebral, avaliando particularmente o arco trigêmeo-facial. Resultados de reflexo do piscamento em pacientes com cefaleias têm mostrado dados controversos. Método Registro das ondas R1 e R2 (ipsilaterais ao estímulo) e R2c (contralateral ao estímulo) por eletroneuromiografia. Resultados Um grande número de controles (n=160) e pacientes com enxaqueca crônica (n=160) foi avaliado. Não foram encontradas diferenças significativas no reflexo do piscamento entre os dois grupos. Conclusão É possível que este reflexo, por ser relativamente simples e primitivo, não esteja alterado a menos que ocorram danos significativos no tronco cerebral. .

Ultrastructural transneuronal degeneration study of axonal elements within the paratrigeminal nucleus in sinoaortic deafferented rats / Estudo ultraestrutural de degeneração transneuronal dos elementos axonais do núcleo paratrigeminal de ratos com desnervação sino-aórtica

Objective: Morphological study that searched to authenticate the presence of sinoaortic baroreceptor inputs within the dorsolateral medullary nucleus under electron microscopy analysis. Methods: After a 5-day survival period, 9 baroreceptor-denervated rats deeply anaesthetized with equithesin were transcardially perfused and their brains were histologically processed. Results: The neuronal cytoarchitecture of the paratrigeminal nucleus comprehends afferent projections from other nuclei that have a distributive character regarding visceral and nociceptive functions in the cardiovascular reflex integration response. Conclusion: The medial portion of the nucleus receives afferent projections of the rostral ventrolateral medulla, as shown by retrograde neurotracing studies. The present results show that the medial extent of the paratrigeminal nucleus contains degenerated axoplasmic cellular components in sinoaortic deafferented rats. The number of degenerated axonal fibers was also larger in this area of the nucleus.

Objetivo: Estudo morfológico que buscou verificar, por meio de microscopia eletrônica, a presença de aferências de receptores sino-aórticos em núcleo localizado na região dorso-lateral bulbar. Métodos: Após 5 dias de sobrevida, 9 ratos com desnervação sinoaórtica anestesiados com equitesina foram submetidos à perfusão transcardíaca, e o encéfalo de cada um deles foi processado histologicamente. Resultados: A citoarquitetura neuronal do núcleo paratrigeminal compreende projeções aferentes de outros núcleos que apresentam uma característica distributiva em relação às funções viscerais e nociceptivas na integração do reflexo cardiovascular. Conclusão: A porção medial do núcleo recebe projeções aferentes da região rostro-ventrolateral do troncoencefálico, confirmadas por meio de estudos com rastreadores neuronais. Os resultados indicam que a região medial do núcleo paratrigeminal contém o maior número de fibras axonais degeneradas.

The Antinociceptive Effect of Sigma-1 Receptor Antagonist, BD1047, in a Capsaicin Induced Headache Model in Rats

Intracranial headaches, including migraines, are mediated by nociceptive activation of the trigeminal nucleus caudalis (TNC), but the precise mechanisms are poorly understood. We previously demonstrated that selective blockage of spinal sigma-1 receptors (Sig-1R) produces a prominent antinociceptive effect in several types of pain models. This study evaluates whether the Sig-1R antagonist (BD1047) has an antinociceptive effect on capsaicin (a potent C-fiber activator) induced headache models in rats. Intracisternal infusion of capsaicin evoked pain behavior (face grooming), which was significantly attenuated by BD1047 pretreatment. BD1047 consistently reduced capsaicin-induced Fos-like immunoreactivity (Fos-LI), a neuronal activator, in the TNC in a dose-dependent manner. Moreover, capsaicin-induced phosphorylation of N-methyl-D-aspartate receptor subunit 1 was reversed by BD1047 pretreatment in the TNC. These results indicate that the Sig-1R antagonist has an inhibitory effect on nociceptive activation of the TNC in the capsaicin-induced headache animal model.

ASSOCIATION OF VESTICULAR GLUTAMATE TRANSPORTERS-AND 5-HT-LIKE IMMUNOREACTIVE VARICOSITIES WITH MESENCEPHALIC TRIGEMINAL NUCLEUS NEURONS IN THE RAT / 神经解剖学杂志

The possible relationship of vesicular glutamate transporters ( VGluT1 and VGluT2 ) - and 5-HT-like immunoreactive (LI) terminals with mesencephalic trigeminal nucleus (Vme) neurons in the rat was examined by using triple-immunofluorescence histochemistry and double-labeled electron microscopic immunohistochemistry. Under confocal laser-scanning microscope, many neuronal cell bodies of Vme showed phosphate-activated glutaminase (PAG) -LI and the vast majority of them were large pseudounipolar neurons. A considerable number of VGluT1 -LI and VGluT2-LI terminals were widely distributed in Vme, the density of VGluT2-LI terminals was higher than that of VGluT1-LI. 5-HT-LI axonal varicosities had dense distribution in Vme, and some 5-HT-LI terminals also showed immunoreactivity for VGluT2. Some VGluT1-LI, VGluT2-LI, 5-HT-LI and VGluT2/5-HT-LI terminals were frequently observed in close apposition to the cell bodies of Vme neurons showing PAG-LI. Under electron microscope, VGluT1/VGluT2-LI and 5-HT-LI were visualized with silver grains and peroxidase products, respectively. Some terminals in Vme showed both VGluT2- and 5-HT-LI, these dual labeled varicosities usually made asymmetric contact with Vme neurons. Synaptic terminals that showed VGluT1-LI was also observed, but no coexpression of VGluT1 and 5-HT was found in Vme. The present results suggest that in the transmission of the proprioceptive sensory information from the orofacial regions to the higher center, glutamate and 5-HT may play important roles on the regulation of Vme neurons through complicated integration.

Processing Mechanism of Sensory Information Originated from the Oral Cavity in the Trigeminal Nucleus Oralis / 대한해부학회지

To analyze the synaptic characteristics of axon terminals originated from the tooth pulp in the trigeminal nucleus oralis, labeling of tooth pulp afferents with wheat-germ agglutinin conjugated horseradish peroxidase and morphometric analysis with electron microscopic photographs were performed. The results obtained from 23 labeled endings were as follows. All of the labeled boutons contained clear and round synaptic vesicles (dia. 45~55 nm). 3 (13.64%) out of 23 labeled endings have 20~105 dense cored vesicles and do not make synaptic contacts with p-endings. But remaining 20 labeled endings (86.36%) almost do not have dense cored vesicles and 12 of them make synaptic contacts with p-endings. The mean number of synaptic contacts was 2.61+/-2.06 and the postsynaptic profiles were usually middle or distal dendrite and dendritic spine (1.74+/-1.36) rather than soma or proximal dendrite. The mean number of synaptic contacts with pendings was 0.87+/-1.01. And the frequency of the synaptic triads were 0.39+/-0.58. The vesicle density was 993.23+/-267.41/mum(2). The volume of labeled bouton was 3.54+/-2.20 mum(3) and highly correlated (P < 0.01) with surface area (11.78+/-4.92 mum(2), r = 0.95), total apposed surface area (2.90+/-1.56 mum(2), r=0.72), total active zone area (0.61+/-0.37 mum(2), r = 0.82), mitochondrial volume (0.75+/-0.53 mum(3), r = 0.94), the number of synaptic vesicles (2621.30+/-1473.61, r= 0.91) and the number of synaptic contacts (r = 0.76). These results suggest that there are two groups of tooth pulp afferent terminals according to the presence of dense cored vesicles in the trigeminal nucleus oralis. And the sensory processing mechanism of each groups may be different. And the "size principle" of Pierce & Mendell (1993) is also applicable to these terminals.

Nucleus Caudalis DREZ Lesioning for Intractable Pain due to Invasive Sarcoma in Skull Base: Case Report

We present a case of nucleus caudalis DREZ operation for medically refractory facial pain due to invasive sarcoma in skull base. The patient showed excellent pain relief immediately after the operation. Until 5 month later, the pain was less than before surgery. At the point of view of pain characteristics and distribution, it was considered the trigemino-vago-glossopharyngeal neuralgia. It is suggested that the nucleus caudalis DREZ operation is effective in treating medically refractory facial pain due to invasive sarcoma in skull base.

CONNECTIONS BET WEEN VESICULAR GLUTAMATE TRANSPORTERS-,GAD-LIKE IMMUNOREACTIVE TERMINALS AND GABA_A RECEPTOR ?3 SUBUNIT- LIKE POSITIVE NEURONS IN MESENCEPHALIC TRIGEMINAL NUCLEUS OF THE RAT / 解剖学报

Objective To observe the association of vesicular glutamate transporter of typeⅠ (VGluT1 ) like immunoreactive(LI) ,the differentiation-associated Na+ dependent inorganic phosphate cotransporter(DNPI) LI and glutami cacid decarboxy lase(GAD) LI terminals with GABAA receptor ?3 subunit(GABAAR ?3) LI neurons in mesencephalic trige minal nucleus of the rat.Methods Triple immun of luorescencehis to chemical staining technique and confo call aser scanning micros copy were used.Results Alargenumber of neuronal cell bodies showed GABAA R?3 LI immunoreactivity atallrostrocaudal level softhe Vme ,and most of GABAAR ?3 LI cells were large (2 5 5 0 ?m)pseudouni polarneurons.The dense VGluT1 LI,DNPL LI and GAD LIterminal sdistri buted widelyin Vme ,some VGlu T1 DNPI LI and GAD LIterminals surrounded the somata of the GABAAR ?3 LI Vmeneurons ,and made close contacts with them .Conclusion Proprioceptive sensory signals from the or of acialregionmight be modulated at the level of the primary afferent cell bodies in the Vme both by glutamatergic and GABAergic axonal terminals from other brain areas,and the effect of GABAergic terminals might be mediated by post synaptical GABAA receptors .

THE RESPONSE AND RELATIONSHIP OF RAT SPINAL TRIGEMINAL NUCLEUS ASTROCYTES AND NEURONS TO PAIN INDUCED BY SUBCUTANEOUS FORMALIN INJECTION / 解剖学报

Objective To investigate the responses of neurons and astrocytes within rat′s spinal trigeminal nucleus(Sp5C) following nocuous pain stimulation induced by subcutaneous formalin injection into the unilateral upper lip. Methods By means of anti\|phospholipase(PLC),anti\|Fos protein and anti\|glial fibrillary acidic protein(GFAP) immunohistochemical method,the distribution of reactive neurons and astrocytes in the Sp5C was observed at different time after formalin injection. Results No immunohistochemical staining was found in normal rat Sp5C.After formalin injection,PLC like immunoreaction(\|LI),Fos\|LI and GFAP\|LI were found in astrocytes while PLC\|LI and Fos\|LI in neurons.The labeled astrocytes and neurons showed similar distribution and close relationship.PLC\|LI and Fos\|LI were found earlier than that in neurons.Conclusion\ The results suggested that the astrocytes in the Sp5C might participate in pain modulation in CNS and actively regulate neuron′s function.

Biphase actions of galanin antagonists at different doses on galanin-evoked outward-current of trigeminal nucleus neurons in rats / 中国临床药理学与治疗学

Aim To observe the effects of galanin (Gal) antagonist M35 or M40 at different concentrations on the Gal evoked outward current in principal trigeminal nucleus (PrV) neurons. Methods The technique of whole cell patch clamp was used to record the change of membrane current. Results At doses of M35 0.01 , 0.03 and 0.1 ?mol?L -1 , the Gal evoked outward current decreased by 53.1 %, 40.4 % and 27.2 %,respectively. While M35 1 and 3 ?mol?L -1 , the current increased by 16.2 % and 38.4 %. At doses of M40 0.01 and 0.03 ?mol?L -1 ,the current increased by 93.7 % and 68.4 %,while for M40 0.3 ,1 and 3??mol?L -1 , the current decreased by 49.2 %, 69.9 % and 87.2 %, respectively. Conclusion M35 at low concentrations antagonizes the effect of Gal and at high concentrations acts as a Gal receptor agonist. Whereas M40 in high doses antagonizes the effect of Gal and in low doses exerts an autagonistic action. There may be different Gal subtype receptors in the same PrV neuron.

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 PROJECTION OF THE CEREBRAL CORTEX TO THE ORAL SUBNUCLEUS OF SPINAL TRIGEMINAL NUCLEUS IN THE CAT——A STUDY WITH THE HRP RETROGRADE TRACING METHOD / 解剖学报

The cortical distribution of thecells of origin of the corticotrigeminal projection to the oral subnucleus of spinal trigeminal nucleus(Vo)was examined with the HRP retrograde tracing method. The results showed that the coronal gyrus was the main site of origin. The anterior part and the posterior part of the gyrus projected to the dorsomedial portion and the ventrolateral portion of Vo respectively. The amount of labelled cells in the anterior part of the gyrus was much larger than those in the posterior. There were also numerous labelled cells in the anterior parts of orbital gyrus and of the lateral zone of anterior sigmoid gyrus. The most anterior ends of these three gyri joined together forming the so-called "presylvian gyrus" where the labelled cells were most concentrated. In addition, the labelled cells were also scattered in the anterior suprasylvian gyrus, posterior sigmoid gyrus, lateral gyrus and anterior ectosylvian gyrus. All labelled cells were located in the fifth layer of the cortex. Their size varied. The results of the present study did not support that there were projections from the temporal and occipital lobes and proreate gyrus to Vo.

NONGLOMERULAR SYNApSES IN THE SUBSTANTIA GELATINOSA OF THE RAT SPINAL TRIGEMINAL NUCLEUS / 解剖学报

Nonglomerular synapses in the neuropil of the substantia gelatinosa of adult ratspinal trigeminal nucleus were subjected to electron microscopic examination. Nonglomerular synapses in the substantia gelatinosa were associated with four main types of axonal terminals. On the basis of vesicle shapes, these were classified as round vesicle, elongate vesicle, pleomorphie vesicle, and dense cored vesicle terminals. The category of round vesicle terminals could be subdivided into large round vesicle terminals and small round vesicle terminals according to their different size of synaptic vesicles. Nonglomerular synapses included four types, i. e. axodendritic, axo-axonic, dendro-dendritic and dendro-axonic synapses. Of these, the majority of synapses were axodendritie. The functional significance of the classification of these synapses and their axonal terminals had been discussed.

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.;

DISTRIBUTION OF GFP-POSITIVE NEURONS AND THE COLOCALIZATION WITH PARVALBUMIN IN THE CAUDAL SPINAL TRIGEMINAL NUCLEUS IN THE GAD67-GFP KNOCK-IN MOUSE / 解剖学报

Objective To observe the distribution of GABA-containing neurons revealed by GFP expression and the colocalization of the GFP with parvalbumin(PV) in the caudal spinal trigeminal nucleus(Vc),the glutamate decarboxylase 67-green fluorescence protein(GAD67-GFP) knock-in mice were used in the present study. Methods Double-labeled techniques were used by in situ hybridization combined with immunohistochemistry for GFP and double immunofluorescence histochemistry for GFP and NeuN(neuronal nuclei protein,a neuronal marker) or PV.The stained sections were observed under light microscope and a confocal laser-scanning microscope. Results 1.Over 90% of GFP-positive neuronal cell bodies in the laminae Ⅰ and Ⅱ of the Vc showed hybridization signals for GAD67 mRNA,and that almost all neuronal cell bodies with GAD67 mRNA signals were GFP-positive;2.GFP-positive neurons were mainly distributed in the laminae Ⅰ and Ⅱ of the Vc and the vast majority of them were small neurons.The considerable number of GFP-positive processes and somata were most densely observed in the lamina Ⅱ of the Vc.The proportion of GFP-positive neurons in the NeuN-labeled neurons of the Vc was about 19.4% and 24.3% in laminae Ⅰ and Ⅱ,respectively;3.Double-labeled neurons for GFP/PV are mainly found in laminae Ⅰ and Ⅱ of the Vc.The proportion of GFP/PV double-labeled neurons was about 62.4% and 12.8% of total population of PV-and GFP-positive neurons in laminae Ⅰ-Ⅱ of the Vc,respectively.Conclusion GABAergic neurons are mainly distributed in the laminae Ⅰ and Ⅱ of the Vc which related closely to transmission of the nociceptive primary afferent information,and the majority of PV-positive neurons are GABAergic neurons.

CONNECTIONS BETWEEN GAD-LIKE IMMUNOREACTIVE TERMINALS AND COEXISTENT POSITIVE NEURONS OF PAG-AND GABA-A-RECEPTOR ?3-LIKE IN THE MESENCEPHALIC TRIGEMINAL NUCLEUS OF THE RAT / 解剖学报

Objective To observe the connections between the glutamic acid decarboxylase\|like immunoreactive(GAD\|LI) axonal terminals and the positive neurons showing phosphate actived glutaminase(PAG)\|LI or GABA\-A\|receptor ?3 subunit (GABA\-AR?3)\|LI and parvalbumin(PV)\|LI in the mesencephalic trigeminal nucleus(Vme) of the rat. Methods The triple\|immunofluoresence histochemical staining techniques were used in the present study,and stained sections were observed under a confocal laser\|scanning microscope. Results Many neuronal cell bodies through the whole rostrocaudal extent of Vme were showed dense GABA\-AR?3\|,PAG\| and PV\|like immunoreactivities,respectively.The majority of them were large pseudounipolar neurons(diameter 25\|50?m).About 90% of PAG\|LI neurons expressed both GABA\-AR?3\|LI and PV\|LI.Confocal laser\|scanning microscope further revealed that dense GAD\|LI axonal varicosities were found to surround the somata of Vme neurons showing both GABA\-AR?3\| and PAG\|like immunoreactivities,and formed the close contact each other.Conclusion\ The present results suggested that the GABAergic axonal terminals projecting to Vme might exert inhibitory regulation and control effect through GABA\-AR?3 subunit localizated in somata of Vme neurons on the transmission of orofacial region proprioceptive sensory information mediated by glutamate.