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Objective@#To evaluate the protective effect of granulocyte-colony stimulating factor(G-CSF) on neonatal rats after hypoxic-ischemic brain damage(HIBD)and its effect on endoplasmic reticulum (ER) stress.@*Methods@#According to the random number table, a total of 54 Sprague-Dawley (SD) rats aged 7 days were divided into 3 groups(18 rats in each group): Sham group, HIBD group and G-CSF group, and the improved Rice method was used to establish a neonatal rat model of HIBD.A dose of 50 μg/kg of G-CSF was administered intraperitoneally 1 hour after HIBD (G-CSF group), while the rats in HIBD group and Sham group received saline only.At 24 hours of HIBD, pups were euthanized to quantify brain infarct volume by using 2, 3, 5-Triphenyltetrazolium chloride.Hematoxylin-Eosin (HE) staining was used to observe the changes of brain structure.Neuronal cell death was determined by using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). Then the expressions of glucose-regulated protein 78 (GRP78), cysteinyl aspartate specific proteinase 12 (Caspase-12), CCAAT/enhancer binding-protein homologous protein (CHOP) were assessed by Western blot and immunofluorescence staining.@*Results@#Twenty-four hours after operation, HE staining showed that no significant neuronal damage was observed in Sham group.The brain tissue structure of rats in the HIBD group was significantly damaged, while some improvement was observed in the G-CSF group.The infarction volume in HIBD group[(25.40±5.15)%] increased compared with that in the Sham group[(0.31±0.15)%] and the G-CSF group[(16.36±4.97)%], and the differences were statistically significant(all P<0.05). There was increased positive expression of GRP78 protein in HIBD group, compared with that in the Sham group and the G-CSF group[(49.38±10.06)% vs.(9.12±4.50)%, (30.61±6.35)%], and the differences were statistically significant (all P<0.05). The percentage of apoptosis in the hippocampal CA1 region and conex in HIBD group [(44.84±11.54)%, (48.23±14.07)%] were higher than those in the G-CSF group [(17.87±7.20)%, (26.18±9.96)%], and the differences were statistically significant (all P<0.05). The expression of GRP78, CHOP and Caspase-12 in the HIBD group (0.63±0.24, 0.72±0.21, 0.68±0.25) were higher than those in the Sham group (0.20±0.08, 0.28±0.08, 0.23±0.07), and the G-CSF group (0.39±0.13, 0.51±0.18, 0.48±0.16), and the differences were statistically significant (all P<0.05).@*Conclusions@#G-CSF exerts neuroprotective effect on the neonatal rats after HIBD.G-CSF may be an effective treatment of HIBD by reducing ER stress-induced neuronal apoptosis.
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Objective@#To investigate the role of granulocyte-colony stimulating factor (G-CSF) on the regulation of inflammatory cytokines in neonatal hypoxic-ischemic brain damage(HIBD) rat model, and to explore the possible mechanism involved in G-CSF neuroprotective effect via the mammalian target of Rapamycin/p70 ribosomal S6 protein kinase (mTOR/p70S6K) signaling pathway.@*Methods@#A group of postnatal day 7 (P7) Sprague-Dawley rat pups (90 cases) were randomly divided into sham-operated group, hypoxia-ischemia(HI) group, G-CSF group, Rapamycin (RAP) group and control group, and the improved Rice method was used to establish a neonatal rat model of HIBD.One hour before HI induction, Rapamycin was administered intraperitoneally with a dose of 250 μg/kg, and the control group was given equal volume of ethanol injected intraperitoneally.One hour after HI, a dose of 50 μg/kg of G-CSF was injected intraperitoneally into the G-CSF group, Rapamycin group and control group.The same volume of normal saline was injected intraperitoneally into HI group and sham-operated group.Forty-eight hours after HI, Western blot was used to detect the protein levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-10, and the mTOR/p70S6K signaling pathway in brain tissue.Neuron injury of the hippocampal CA1 region and the cortex was assessed by Nissl staining, and infarct volume detected by 2, 3, 5-triphenyltetrazolium chloride staining.@*Results@#The G-CSF group and control group were associated with significantly reduced infarction volume compared to the HI group [(12.87±1.54)%, (11.90±1.31)% vs.(24.21±3.28)%], and the differences were statistically significant(P<0.05). There was an increased positive neuron cell number in the ipsilateral hemispheres of the hippocampal CA1 region in the G-CSF group and the control group [(61.00±4.90) cell/field and (61.67±6.40) cell/field] and cortex [(92.67±6.68) cell/field and (90.17±4.45) cell/field] compared with those in HI group [(42.62±4.46) cell/field and (70.83±6.97) cell/field], and the differences were all statistically significant (all P<0.05). The expression levels of TNF-α and IL-1β were significantly decreased in the G-CSF group and the control group, compared with those in HI group(TNF-α: 0.67±0.07, 0.55±0.05 vs.0.86±0.05; IL-1β: 0.65±0.06, 0.52±0.10 vs.0.86±0.06), and the differences were all statistically significant (all P<0.05). There was increased expression levels of IL-10, p-mTOR/mTOR and p-p70S6K/p70S6K in the G-CSF group and the control group, compared with those in HI group (IL-10: 0.68±0.04, 0.62±0.05 vs.0.34±0.02; p-mTOR/mTOR: 0.53±0.02, 0.51±0.01 vs.0.26±0.01; p-p70S6K/p70S6K: 0.89±0.03, 0.90±0.03 vs.0.55±0.02), and the differences were all statistically significant(all P<0.05). There was an increased infarct volume in Rapamycin group [(25.70±1.50)%], compared with the G-CSF group and the control group, and there were decreased number of positive neuron cell count in the hippocampal CA1 region [(40.67±3.50) cell/field] and cortex [(68.33±8.17) cell/field], increased expression levels of TNF-α and IL-1β (0.97±0.06 and 0.98±0.10, respectively), decreased expression levels of IL-10, p-mTOR/mTOR and p-p70S6K/p70S6K (0.21±0.02, 0.30±0.01 and 0.55±0.01, respectively) in the Rapamycin group, and the differences were all statistically significant (all P<0.05).@*Conclusions@#G-CSF may inhibit inflammatory responses after HIBD by up-regulating the mTOR/p70S6K signaling pathway in neonatal HI encephalopathy.
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As an inhibitory amino acid similar to gama-aminobutyric acid,taurine can activate the corticostriatal pathway as an endogenous ligand for glycine receptors,establishing equilibrium between the excitatory and inhibitory processes in the brain.In mammalian brains,taurine concentrations increase during the developmental period of the brain until weaning,and subsequently decline reaching stable concentrations in adulthood.With abilities of anti-oxidative stress,anti-inflammatory and anti-apoptosis,taurine can improve the hypoxic-ischemic brain injury,promote the proliferation and differentiation of neurons and affect brain development,It needs more investigations to prove when and how taurine supplementation during gestation,baby,children or adult can assist the development of the brain and prevent the damage of the brain from hypoxic and ischemic damage.
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Objective To investigate the neural representations of long-term digital memory in human brain by functional magnetic resonance imaging (fMRI) technique. Methods 22 right-handed normal volunteers were recruited to participate in a test of long-term digital memory while the fMRI data were recorded. Control tasks were performed for the block-design. SPM 99 was used to analyze the data and to obtain the activated brain regions.Numbers of activated voxels were used to calculate lateralization index (LI). Results When the threshold was set as P＜0. 0001 ,using a one-sample t -test,the middle gyrus of the left frontal lobe(t=9.68) and the right cerebellum ( t = 9.85 ) were activated remarkably during the memory task. The subcortical structures including the thalamus (t=6.72) and the caudate (t=6.58) were also obviously activated during the memory task. LI of the numbers of activated voxels was 0.51. Conclusions The subcortical structures and the cerebellum as well as the cerebral cortex are collaborative to contribute to long-term digital memory function in human brain. The results also reveal that the functional areas of long-term digital memory in human brain are localized with the functional lateralization in the left hemisphere.
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Objective To examine whether the marginal division of the striatum(MrD)is involved in the associative learning and memory function of human brain with the help of functional magnetic resonance imaging(fMRI)technique.Methods Sixteen right-handed normal volunteers participated in a test of paired-word associative learning and memory,while the fMRI data were recorded.Control tasks were performed for the block-design.Statistcs parameter mapping 99 was used to analyze the data and to obtain the activated brain regions.Results When the threshold was set as P＜0.005.using a one-sample T-test,the left occipital lobe and the superior and middle gyrus of the left frontal lobe were activated remarkably during the encoding process of the paired-word associative learning and memory task,with the maximum intensity T value being 13.87 and 9.36.respectively.The left MrD was also obviously activated during this stage(T value was 5.46).But during the retrieval process,the left parietal lobe was prominently activated(T value was 8.73).Conclusion The resuhs of this study reveal that the subcortical structures such as MrD as well as the cerebral cortex are involved in the associative learning and memory of paired-word in human brain.
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BACKGROUND: The marginal division, a new sub-region in rat brain striatum discovered in recent decades, has been found to closely relate to learning and memory function of the brain. The immediate-early genes such as c-fos and c-jun participate in the signal transduction of learning and memory in the marginal division. But what other intermediate events are initiated in the marginal division in the process of learning and memory?Cyclic adenosine monophosphate (cAMP) response element-binding protein (CREBP) is an molecule essential for the formation of long-term memory,and investigation of the expression and distribution of phosphorylated CREBP in the striatum may help understand the signal transduction mechanism in the striatum during learning and memory at the molecular level.OBJECTIVE: To investigate the expression of phosphorylated CREBP in rat brain stratum during learning and memory process.DESIGN: Completely randomized controlled study.SETTING: Institute of Neurosciences, Zhujiang Hospital of the First Military Medical University of Chinese PLA.MATERIALS: This experiment was conducted in the Institute of Neurosciences, Zhujiang Hospital of the First Military Medical University of Chinese PLA between April and August 2003. Totally 48 normal male adult SD rats were provided from the Experimental Animal Center of First Military Medical University, and after two Y-maze tests, 40 rats were selected for this study (MG-2 type, Sanshengxing electricity company).METHODS: The 40 SD rats were randomized into 4 equal groups. The rats in the first group were subjected to training to acquire dark avoidance reflex in a Y maze, those in the second group underwent sham training with only light stimulation in the Y maze without electricity on the floor.The rats in the third group were trained in the Y maze with electricity on the floor but not light stimulations, with the rest 10 rats serving as the control group subjected to sham training in the Y maze without either electric or light stimulations. After the training in the Y maze, the rats were sacrificed immunohistochemical detection of phosphorylated CREBP expression in the brain striatum.MAIN OUTCOME MEASURES: Expression of phosphorylated CREBPin rat brain striatum.RESULTS: All the 40 rats enrolled in this study were examined for phosphorylated CREBP expression. Positive expression of phosphorylated CREBP was observed in the medial marginal division of the brain striatum after the rats were trained in the Y maze with electric stimulation, but no obvious expression was seen in rats in the sham training or control groups.Massive expression of phosphorylated CREBP could be observed, typically,in the hippocampus, front prefrontal lobe cortex and cingulate gyrus of the rat brain.CONCLUSION: The transcriptional factor phosphorylated CREBP in the marginal division of the striatum participates in the signal transduction for learning and memory in rats receiving Y maze training to acquire dark avoidance reflex.
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BACKGROUND: Hippocampal structure in brain is the division related to learning and memory, generally it is closely relevant to spatial cognitive activity. Marginal division of striatum is a latest discovered subdivision related to learning and memory function of brain, whether is its learning and memory function different from that in hippocampus?OBJECTIVE: To compare the difference, function and importance in learning and memory function between marginal division of striatum and hippocampus in brain and observe the difference in escape learning and memory between marginal division of striatum and hippocampus.DESIGN: Completely randomized controlled experiment.SETTING: Institute of Neuroscience in Zhujiang Hospital Affiliated to First Military Medical University of Chinese PLA.MATERIALS: The experiment was performed in Institute of Neuroscience in Zhujiang Hospital Affiliated to First Military Medical University of Chinese PLA from March 2002 to July 2003. Totally 109 normal male adult SD rats were employed and 75 rats of them were screened as the qualified animals by twice Y-maze test. Randomly, 25 rats were divided into damaged marginal division of striatum group (DMD group), 10 rats were into bilateral fimbria-fornix transection group (FFT group), 30 rats were into the control of marginal division of striatum (MD control) and 10 rats were into the control of bilateral fimbria-fornix group (FF control). After 24 hours training in Y-maze,In DMD group, 10 g/L kainic acid 0.1 to 0.2 μL was used to damage bilateral marginal division of striatum of rats. In MD control, physiological saline of minim dose was injected in bilateral marginal division of striatum of rats. In FFT group, bilateral fimbria-fornix was transectioned. In FF control, the cortical tissue of the superficial layer of bilateral fimbria-fornix was transectioned. The operation was done on the second day after the 2nd screening. The behavior of rats in learning and memory was observed in Y-maze on the 5th day after operation (during 30 times of maze test, if success frequency ≥ 15,normal capacity of learning and memory was identified.).MAIN OUTCOME MEASURES: Success frequency of rats in different groups in Y-maze learning before and after operation.RESULTS: Of 109 normal male adult SD rats, 75 rats were screened to be qualified after twice Y-maze test. During the experiment, 3 rats were died and other 32 rats fell into disuse for the drug or physiological saline was not injected accurately to the marginal division of striatum. Terminally, 40 rats entered the analysis in total, of which, 11 rats were in DMD group, 9 rats in MD quency in Y-maze learning of rats in DMD group after operation was lower than MD control, FFT group and FF control [(9.27±4.29) times, (22.56±4.25)frequency in Y-maze learning of rats in DMD group after operation was also significantly lower than that before operation [(9.27±4.29) time, (18.27±3.07)FFT group was basically same as FF control and MD control (P=0.660 and P=0.489) and it was basically same to the success frequency in Y-maze learning before operation (P=0.700).CONCLUSION: The learning of Y-maze in rats with damaged marginal division of striatum was remarkably reduced and there was no obvious change in learning and memory between the rats with fimbria-fornix transaction and without transaction. It is verified that marginal division of striatum can reflex complex learning and memory behavior in electric Y-maze test, which cannot be achieved in hippocampus. It is further explained the difference of the two divisions in controlling learning and memory in cerebrum, the marginal division of striatum is able to control hippocampus in learning and memory function.
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To understand the relationship of neurotransmitter between the striatum and limbic system such as amygdaloid nucle-us and bed nucleus of the stria terminalis. 30 male Sprague Dawley rats were used. Immunohistochemical ABC method was per-formed to detect the expression of substance P (SP), calcitonin gene-related peptide (CGRP), leucine-enkephalin (L-enk),cholecyctokinin (CCK) and neuronal nitric oxide synthase (NOS) on seetions of the brain. Some transmitters including substanceP, calcitonin gene-related peptide and cholecyctokinin were mainly distributed at the marginal division of the striatum. Theleucine-enkephalin was mainly distributed at the globus pallidus and was secondly distributed at the marginal division of the stria-tun. The neuronal nitric oxide synthase was mainly distributed at caudate putamen and the marginal division. All these transmit-ters were not only distributed at amygdaloid nucleus and bed nucleus of the stria terminalis, but also had fibers connection amongthe amygdaloid nucleus, marginal division and bed nucleus of the stria terminalis. CONCLUSION: There were special fibersconnection between the marginal division and other basal ganglia nucleus or the limbic system. The marginal division may beplayed some important functions of basal ganglia and limbic system.
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A glucose oxidase-3,3′ diaminobenzidine-nickel method was developed.Thistechnique can successfully demonstrate the details of the immunoreactive structuresand PHA-L labeled cell bodies and their processes.It is especially beneficial forvisualizing fibers and terminals.It is more sensitive than the regular 3,3′ diamino-benzidine method and the glucose oxidase-3,3′ diaminobenzidine technique,andvery stabilized.
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Using immunohistochemical method, the distribution of eight kinds of peptidergic neurons, i. e. cholecystokinin(CCK),vasoactive intestinal polypeptide (VIP), substance P(SP), neurotensin (NT), galanin (GAL), calcitonin gene-related peptide (CGRP), corticotropin-releasing factor(CRF) and thyrotropin-releasing hormone(TRH), of the thalamus in the rat was investigated. Immunoreactive cell bodies and fiber terminals were mainly located in the midline nuclei, intralaminar nuclei, habenular nucleus and posterior nuclei of the thalamus, but a few of positive structures in the anterior nuclei, ventral nuclei and reticular nucleus were also found. The distribution of different peptidergic neurons in the thalamus was different from each other. A large quantity of SP-, NT- and GAL- like cell bodies and all of above-mentioned eight peptidergic fiber terminals were observed in the midline nuclei and intralaminar nuclei. More CCK and CGRP positive cell bodies were seen in the posterior nuclei. Some VIP, SP, NT, GAL and CRF positive cell bodies and all kinds of the positive terminals, except CGRP, were found in the habenular nucleus. The immunoreactive structures which were found in present study, particularly the distribution of positive terminals, were more widely than those were reported. The distribution of some CCK, VIP, NT, GAL, CGRP and TRH positive cell bodies and terminals in the thalamus have not been reported previously.
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It was discovered that there were a group of gigantic neurons scattering in the tegmentum dorsolateral to the oral half of the red nucleus in the midbrain of the rabbit. The form and size of these neurons were similar to the gigantic cells in the gigantocellular reticular nucleus of the medulla oblongata. After injecting HRP or WGA-HRP in the cervical, thoracic or lumbar spinal segment of the rabbit, more than a half of these gigantic cells were labeled. The labeled cells were most crowded at the oral end level of the red nucleus. There were also labeled terminals near the labeld cells in the reticular formation of the midbrain. It is evidently that there are reciprocal connections between the spinal cord and the reticular formation of the midbrain in the rabbit.
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The somatotopical pattern of the spinal projection to the lateral reticular nucleus (LRN) was examined in 16 rabbits. The anterograde transport of HRP method were used.1. Cervical, thoracic and lumbar segments all gave rise to small numbers of fibers projecting to bilateral lateral reticular subtrigeminal subnucleus (Lrs).2. Cervical, thoracic and lumbar projections to the LRN were bilateral but the cervical ascending fibers terminated predominately on the ipsilateral side. The lumbar ascending fibers projected chiefly to the contralateral side. The thoracic cord gave fibers to bilateral LRN. No significant difference could be seen between the two sides. There were certain overlapping among the distribution areas of the terminal branches from different parts of the cord.3. The spinal projections of the rabbit were predominately terminated in the caudal half of the LRN. It showed a somatotopical pattern. The cervical cord projected to the lateral 3/5 of the lateral reticular magnocellular subnucleus (Lrm) and its neighbouring part of the lateral reticular parvocellular subnucleus (Lrp). The thoracic cord projected to the medial 3/5 of the Lrm and its neighbouring part of Lrp. The lumbar cord gave afferents to the Lrp and its neighbouring part of Lrm.
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The somatotopical projection from the lateral vestibular nucleus to differentlevels of the spinal cord in the cat was studied with the horseradish peroxidasemethod.It was found that in the lateral vestibular nucleus the cells projecting tothe cervical and lumbar segments of the cord were distributed over the entire ros-trocaudal extent,each with an area of concentration.The caudal and middle thirdsof the nucleus,especially its dorsolateral part,projected to the lumbar cord.Thecells projecting to the cervical cord were concentrated at the rostral-middle thirds ofthe nucleus and those to the thoracic cord were concentrated at the dorsal part ofthe caudal-middle thirds.The area projecting to the thoracic levels seemed tocoincide with that projecting to the lumbar levels.The cells projecting to thelumbar cord were largest in number,those to the cervical cord less and those to thethoracic cord least.
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The localization of the neurons which control the inferior oblique muscle in the oculomotor nucleus and their dendritic architecture were studied by injecting the conjugated cholera toxin-horseradish peroxidase (CT-HRP) into the inferior oblique muscle of 7 rabbits.The oculomotor nucleus could be divided into oral, middle and caudal parts. The middle part was further divided into dorsomedial and ventrolateral parts, and the caudal part divided into dorsal and ventral parts. The labeled neurons innervating the inferior oblique muscle were mainly distributed ipsilaterally and occupying two thirds. of the rostrocaudal extent of the oculomotor nucleus, a few were scattered contralaterally.The labeled cells were found in the dorsomedial part of the nucleus orally, and shifted in successive caudal sections to the medial and then to the ventral part. No labeled cells in the oral and caudal ends of the nucleus could be identified.The dendritic branches of the labeled neurons covered the whole nucleus, but densest in its dorsomedial part. Many of them extended beyond the boundary of the nucleus into the central gray matter dorsally, some even approacheding the aqueduct, or through the medial longitudinal fasciculus into the reticular formation laterally and ventrally. A few dendrites crossed the midline into the contralateral nucleus. Therefore the receptive field of the oculomotor nucleus is presumably much larger than the area of the nucleus itself.
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The origin and termination of the reticulospinal tract were studied with HRP technique in ten cats by injecting HRP into the spinai dorsal horn or gray matter on one side of the cervical or lumbar enlargement, It was discovered that the reticulospinal neurons were located not only in the medial part of the medullopontal tegmentum, but also in its lateral part. There were also a few scattered labeled neurons in the reticular formation of midbrain. The reticulospinal tract ended in the spinal dorsal horn as well as in the ventral horn. The reticulospinal tract mainly originated from the ventromedial part of the medulla and pons. In this region the labeled cells were most numerous in the nucleus gigantocellularis, less in the nucleus medulla oblongatae centralis subnucleus ventralis and the nucleus pontis centralis caudalis, and much less in the nucleus pontis centralis oralis, the nucleus paragigantocellularis laterlris and the paramedium reticularis subnucleus ventralis. Occasionally a few scattered abeled cells could be seen in the nucleus cuneiformis. The reticulospinal fibers from these nuclei projected bilaterally to both cervical and lumbar enlargments of the spinal cord except that the nucleus cuneiformis projected bilaterally to the cervical enlargement only.Two groups of labeled cells were found in the ventrolateral part of the medullary and pontal reticular formation, corresponding to the position of group A 1 and A 7 of noradrenergic neurons respectively.The reticulospinal tract derived from the medial part of the brain stem terminated predominately in the gray matter ventral to the spinal dorsal horn, but a few of them ended in the dorsal horn. These connections provide direct pathways for the control of motor and sensory functions of the spinal cord by medial reticular formation.It has been proved by Brodal with chromatolysis techenique that every cell in the nucleus paramedium reticularis sends its efferent fiber to the spinal area of cerebellum, but in this study labeled cells were found in e nucleus paramedium reticularis subnucleus ventralis. We suppose that the axons of these labeled neurons may be divided into two branches, one projecting to the cerebellum and the other to the spinal cord.It is noteworthy that we also found some labeled neurons in the nucleus medullae oblongatae centralis subnucleus dorsalis and nucleus parvocellularis, the so called "receptive region" of the reticular formation. The fibers originating from this region terminated in the spinal dorsal horn mainly, suggesting that this tract probably influences the sensory function of the spinal cord. It seems that the conception of the lateral reticular formation of the brain stem as a pure "receptive area" of the reticular formation may have be modified.
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HRP was injected into the cervical (3 cases) or lumbar (2 cases) spinal cord unilaterally in 5 adult cats. Labeled cells were discovered in the hypoth alamus and nearby areas. There was no obvious difference in labeling between cervical and lumbar injection cases. Labeled cells were found bilaterally with ipsilateral preponderance.he paraventricular nucleus was most heavily labeled; the posterior and lateral hypothalamic areas were less. A few labeled cells were found in the dorsal hypothalamic area and the supramamillary nucleus. Forel's area was also weakly labeled and occasional cells were found in the subthalamic nucleus and zona incerta.We were unable to find labeled cells in the dorsomedial nucleus. Labeling of the supramamillary nucleus, which was found in this sutdy, has not been mentioned in the literature available to us.
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The dorsal accessory olivary nucleus was studied with electron microscope in seven rabbits.The axo-axonal synapses,an axon being in contact synaptically with a spine of a perikaryon,the glomerulus with an axonal core and a bundle of microfibers within a nucleus of a neuron,as well as the already discovered axo- dendritic synapses,axo-somatic synapses and glomeruli with dendritic cores,were observed in this nucleus. The axo-dendritic synapses were often seen,the postsynaptic components of them were dendrites or spines.The axo-somatic synapses were fewer.An axonal terminal was seen synapsing to both a spine of a perikaryon and a dendrite.Both the presynaptic and postsynaptic components of the axo-axonal synapses contained spherical vesicles.Sometimes the axo-axo-dendritic synapses were observed.There were two kinds of glomeruli in this nucleus,one with dendritic core and the other axonal core.Two axons were discovered simultaneously synapsing with an axon. The complex synaptic pattern in the dorsal accessory olivary nucleus indicated that the afferent impulses would undergo diffusing,converging,presynaptic inhibition or integrating in this nucleus.
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HRP was injected into the right side of the cervical or lumbar enlargement ormidthoracic segment of adult cats.Retrogradely labeled cells in the red nucleuswere examined and their somatotopic localization was determined.1.The Rubro-spinal projection was mainly crossed with obvious somatotopiclocalization.The dorsal medial part of the red nucleus projected to the cervicalenlargement.The ventral lateral part of the red nucleus projected to the lumbarenlargement.The neurons between these two parts projected to the thoracic cord.2.In cervical and lumbar injected cases a few labeled cells were found also inthe ipsilateral red nucleus,suggesting a minor ipsilateral rubrospinal projection exist-ed.No ipsilateral labeling was found in the thoracic injection cases.3.The rubrospinal tract could at least project to as low as L 6 segment of thespinal cord.
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Aging changes of neurotensin-like (NT-L) and galanin-like (GAL-L) cell bodies and fiber terminals in the central amygdaloid nucleus between the young and old rats were studied by means of immunohistochemical and microspectrophotometric techniques. NT-L cell bodies were mainly located in the central part (CeLn) of, centrolateral amygdaloid nucleus, a few of NT-L neurons were also found in the centrolateral amygdaloid nucleus, capsular part (CeLc) and centromedial amygdaloid nucleus (CeM). NT-L fiber terminals were seen mainly in the CeLn and CeLc. GAL-L cell bodies were observed only in the CeM. A marked decrease of density of NT-L cell bodies and fiber terminals in the central amygdaloid nucleus was found in the old rats as compared with young animals. No significant age difference in number of GAL-L cell bodies was observed in the central amygdaloid nucleus, but the staining intensity of GAL-L cell bodies was reduced remarkably. The results show that there are apparent changes with aging of the NT-L and GAL-L neurons in the central amygdaloid nucleus of the rat. The significance of the changes remains to be studied further.
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Using the immunohistochemical method combined with tract tracing techniques, a new subdivision, the marginal division, was found in the striatum of the rat. In this subdivision, substance P, enkephaline and dynorphin B terminals were densely localized. The present study investigated the synaptic organization of the substance P-like immunoreactive nerve terminals in the marginal division. Four major types of substance P immunoreactive synapses were identified. Axodendritic and axospinous synapses were the most common ones. Compound synapses with more than two synaptic components were also observed. One axo-axonic synapse was present. Both symmetric and asymmetric substance P-like immunoreactive synapses were seen in the marginal division. The existence of asymmetric synapses, small postsynaptic dendrites and axo-axonic synapses, distinguished the substance P-like immunoreactive nerve terminals in the marginal division from those in the other part of the striatum. The characteristics and complexity of the synaptic organization suggested that the substance P-like immunoreactive nerve terminals in the marginal division probably orginate from a different source and have a different function, as compared to those in the rest part of striatum.