No abstract available.
Olfactory Bulb* ; Signal Transduction*

Animal models for human chronic pain syndromes were developed and widely used for pain research. One of thsese neuropathic pain model by Kim and Chung[1992] has many advantages for operation and pain elicitation. We have examined the c-fos protein, substance P, CGRP immunoreactivity in dorsal root ganglia and dorsal horn in this neuropathic model. About 50 Sprague-Dawley rats were used for this study. L5 and L6 spinal nerve were ligated tightly to produce neuropathic pain model. After 2, 4, 8, 16, 24 hours and 1 week of surgery, rats were anesthesized and sacrificed by perfusion through the left ventricle with saline followed by 0.1M phosphate buffer[pH 7.4] containing 3% paraformaldehyde, 3% glutaraldehyde, and 0.1% picric acid. After confirmation of the roots transected by the surgery, the L5 and L6 dorsal root ganglion and spinal cord were removed and processed for immunohistochemistry. All tissue sections were immunohistochemically stained for substance P, CGRP and c-fos by using the peroxidase-antiperoxidase[PAP] method. Count the number of immunostained substance P and CGRP dorsal root ganglion cells and c-fos immunoreactive dorsal horn cells and analyzed statistically with Mann-Whitney U test. The results are as follows. 1. The number of c-fos protein immunoreactive neurons in the superficial layer of dorsal horn were increased markedly at 2 hours after operation, gradually decreased to normal level 1 week after operation. 2. The number of c-fos protein immunoreactive neurons in the deep layer of dorsal horn were gradually increased to the peak 24 hours after operation, decreased to normal level 1 week after operation. 3. The number of substance P and CGRP immunoreactive L5 and L6 dorsal root ganglion neurons were decreased markedly at 1 week after pain model operation. In conclusion, after neuropathic pain model operation, c-fos protein were immediately expressed in the superficial layer of spinal dorsal horn, thereafter c-fos protein in the deep layer of spinal dorsal horn were expressed. CGRP and substance P immunoreactive neurons were decreased markedly 1 week after neuropathic pain model operation.
Animals ; Chronic Pain ; Ganglia, Spinal* ; Glutaral ; Heart Ventricles ; Horns* ; Humans ; Immunohistochemistry ; Models, Animal ; Neuralgia ; Neurons* ; Perfusion ; Peripheral Nervous System Diseases* ; Posterior Horn Cells ; Rats* ; Rats, Sprague-Dawley ; Spinal Cord ; Spinal Nerve Roots* ; Spinal Nerves ; Substance P

No abstract available.
Animals ; Rats* ; Somatotrophs*

The present study was designed to elucidate the effects of rostral basal forebrain lesions on neuropeptide containing neurons in the cerebral cortex. Nine male Sprague-Dawley rats[250-300gm] received bilateral injections of ibotenic acid into the basal forebrain[A : +0.7mm, L : 2.3mm, D : 8.6mm] and additional five served as sham operated animals. Brains were removed at 8-14 days after lesioning and frozen coronal sections of 40 micrometer thickness were made. Immunohistochemical staining was performed against the somatostatin[SOM], neuropeptide Y[NPY], and vasoactive intestinal polypeptide[VIP]. No differences were observed in the number of the SOM-immunoreactive[SOM-ir] or NPY-ir neurons between the lesioned and the control groups. Density of the NPY-ir fibers also did not show any significant difference between the two groups. In contrast, the number of VIP-ir neurons in the frontal cortex was significantly reduced following the basal forebrain lesioning. These results suggest the functional relationship between the basal forebrain and the cortical VIP-ir neurons.
Animals ; Brain ; Cerebral Cortex* ; Humans ; Ibotenic Acid ; Immunohistochemistry ; Male ; Neurons* ; Neuropeptide Y ; Neuropeptides* ; Prosencephalon* ; Rats* ; Rats, Sprague-Dawley ; Somatostatin ; Vasoactive Intestinal Peptide

It is well known that the spatial patterns of basement membrane[BM] components show a close correlation with the morphogenetic process in developing organs during pre- and postnatal period. But little is known about the chronological changes in BM components during the development of thyroid gland. To investigate the correlation of the distribution of BM components with the development of the thyroid gland, immunohistochemical localization of the BM components was performed, using rat fetuses[from 15 to 21 days of gestation] and pups[from 1 to 14 days]. According to the histological features with H.E. staining, prenatal development[El5-21] of the rat thyroid could be divided into 3 representative stages : 1] Undifferentiated primordium of thyroid epithelia, forming cell cords or cell nests [until El5 day]. 2] An intervening stage of cell proliferation with the pattern of lobulation[El6-17 days]. 3] Stage of maturing follicles[El8-21 days]. It could be concluded that differentiation of the thyroid follicle are terminated during the prenatal period and growth in size and number occurs during the first two weeks after birth. By the immunohistochemical localization of laminin[LM], fibronectin[FN], type IV collagen[CIV], the basement membranes investing thyroid follicles could be clearly delineated at 15 days of gestation. Reactivity for LN and CIV associated with BM increased with advancing development, while that of FH was apparently weakened during the 2 weeks after birth. On the other hand immunoreactivity for CIV in the same age group increased, compared to that of previous swage of development. These results indicate that BM components were expressed in distinct spatial patterns with advancing development of thyroid gland. Based on these observations, it could be concluded that these BM components are important determinants in epithelial growth and differentiation during thyroid development.
Animals ; Basement Membrane* ; Cell Proliferation ; Collagen Type IV ; Fibronectins ; Hand ; Humans ; Laminin ; Parturition ; Pregnancy ; Rats* ; Thyroid Gland*

Cell proliferation index in the thyroid is regarded as an important marker for predicting the prognosis and for differential diagnosis of thyroid tumors. Among the methods for the detection of cell proliferation in histological sections, immunohistochemistry for PCNA and BrdU are the most preferable ones. In this study, we evaluated the regeneration process of the thyroid in the rat after surgical resection with special respect to the cell proliferation revealed by both PCNA and BrdU immunohistochemistry, and compared these two results. Rat thyroid was resected bilaterally, about 50~60% of the total lobe in volume, and the tissues were obtained 1, 2, 3, 4, 5, and 7 days after operation, immunohistochemistry was done, and positive and negative cells were counted. The regeneration pattern reflected by cell proliferation was basically same in both PCNA and BrdU immunohistochemistry, except that the positive ratio for PCNA was 4~6 fold higher than that for BrdU in general. In the control thyroid, positive cells were rare. However, the ratio of positive cells increased immediately after the operation, on day 1, and reached at its peak on day 2. The high ratio sustained until day 4, after which the ratio declined abruptly. Through the experimental days, positive cells were more crowded in the area adjacent to the resection plane than elsewhere, suggesting that the areas are more active regenerating focus. Although the pattern of proliferation was same both in PCNA and BrdU immunostaining in terms of time and localization, BrdU staining was easier to read and seeded to reflect cell prolifer-ations more specifically than PCNA staining.
Animals ; Bromodeoxyuridine* ; Cell Proliferation ; Diagnosis, Differential ; Immunohistochemistry* ; Prognosis ; Proliferating Cell Nuclear Antigen* ; Rats* ; Regeneration* ; Thyroid Gland*

The origin of sympathetic and sensory nerves innervating heart in the cat was investigated using HRP (Horseradish peroxidase) and WGA-HRP (Wheat germ agglutinin-horseradish peroxidase) as neuronal tracers. The neural tracers were injected into subepicardial layer and myocardium of the right atrium, left atrium, right ventricle and left ventricle, respectively. Labeled sympathetic neuronal cell bodies were found in superior cervical ganglia, middle cervical ganglia, stellate ganglia and 4th and 5th thoracic ganglia, mainly in middle cervical ganglia and stellate ganglia. Heavier labeled neuronal cell bodies were found in the middle cervical ganglia and stellate ganglia when the neural tracers were injected into left atrium, right ventricle and left ventricle. Labeled sensory neuronal cell bodies were found in nodose ganglia and T1-T6 spinal ganglia, mainly in T1-T5 spinal ganglia. Heavier labeled neuronal cell bodies were found in the nodose ganglia when the neural tracers were injected into left atrium and right ventricle. These results may provide a neuroanatomical data on origin of sensory nerves innervating the heart of the cat.
Animals ; Cats* ; Ganglia ; Ganglia, Sensory ; Ganglia, Spinal ; Ganglia, Sympathetic ; Heart Atria ; Heart Ventricles ; Heart* ; Horseradish Peroxidase ; Myocardium ; Neurons* ; Nodose Ganglion ; Sensory Receptor Cells ; Stellate Ganglion ; Superior Cervical Ganglion ; Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate*

The motor evoked potential (MEP) elicited by transcranial or transcortical stimulation has been advocated as a method of monitoring the integrity of spinal efferent pathways in the various animal models. It was also defined that MEPs were composed of a short latency, direct, synapse free D-wave and a later latency, indirect, synapse mediated I-wave. The authors designed to study pyramidal MEP in rat, because we would understand and use pyramidal MEPs as human efferent spinal pathway monitoring tools during the spinal cord operation in the future. Thirty-two Sprague-Dawley rats were involved in this study. A stainless steel electrode was placed in the hindlimb motor cortex. It was stimulated with 1~4 Hz mono-rectangular pulse waves and 0.1~5 mA in stimulation intensity during short duration. Teflon coated wire electrode was used to record MEP in the spinal cord. MEPs after internal capsule cutting and post-mortem MEPs were recorded finally to exclude the possibility of extrapyramidal MEPs. At the level of medulla oblongata and seventh cervical segment (C7), the recorded MEPs showed positive-negative-positive complex D-wave and a large I-wave activated by presynaptic fibers and monosynaptic depolarization of pyramidal cells. But, at eighth thoracic segment (T8), only large negative I wave, in which prolonged D wave would be included, was recorded. From cortex to seventh cervical spinal cord at 1 mA stimulation intensity, the estimated conduction velocity of D-wave was approximately 11.01+/-0.20 m/sec and that of I-wave was 2.53+/-0.02 m/sec in this study. After internal capsule cutting and postmortem state, both D and I waves were disappeared. Loss of waves indicated that not the extrapyramidal pathway potentials but the pyramidal pathway potentials were recorded selectively. This successful preferential activation of pyramidal MEP in rat demonstrated the possibility of clinical availability during the spinal, especially cervical motor tract monitoring and evaluation. If repeated study would be continued in human, MEP will be more available in clinical field.
Animals ; Efferent Pathways ; Electrodes ; Evoked Potentials, Motor* ; Hindlimb ; Humans ; Internal Capsule ; Medulla Oblongata ; Models, Animal ; Motor Cortex ; Polytetrafluoroethylene ; Pyramidal Cells ; Rats* ; Rats, Sprague-Dawley ; Spinal Cord* ; Stainless Steel ; Synapses

The calcium-binding protein parvalbumin (PV) was localized in the basolateral amygdala of the rat, cat, dog and monkey using immunohistochemical techniques. In all species, neuronal cell bodies and fibers that are immunoreactive to PV were observed in the basolateral amygdala. In most of the amygdala, PV-immunoreactive cells had the appearance of aspiny local circuit neurons. Based primarily on the shape of the soma, PV-immunoreactive aspiny neurons were divided into three main types. Type 1 cells had a spherical soma and more than 3 dendrites, type 2 cells had angular and multipolar somata of variable sizes, and type 3 cells had fusiform somata and dendrites emanated from the opposite poles of somata. PV-immunoreactive varicose fibers formed basket-like plexi around unstained neurons, which suggests that PV is located in GABAergic basket cells, respectively. PV-immunoreactivities in the mammalian basolateral amygdala were morphologically similar, rather than different in all species.
Amygdala* ; Animals ; Carisoprodol ; Cats ; Dendrites ; Dogs ; Haplorhini ; Immunohistochemistry ; Neurons* ; Rats

Periodontal-masseteric reflex is implicated in the control of jaw movement and masticatory force during chewing foods. This study is aimed to investigate the synaptic arrangement of mesencephalic periodontal afferents in the trigeminal motor nucleus and to identify the neurotransmitter involved in the presynaptic control of them through the intra-axonal staining of horseradish peroxidase combined with postembedding immunogold methods. Most of the labeled terminals showed synaptic contacts with the small sized dendritic shafts or distal dendrites, while synaptic contacts with the somata or proximal dendrites were not observed. More than one third of the analyzed labeled boutons received presynaptic input from pleomorphic vesicles containing ending (p-ending). About 11% of labeled boutons showed synaptic triads. All the analyzed boutons made synaptic contacts with one to four neuronal profiles and those showing synaptic contact with five or more were not observed. Labeled terminals were larger than presynaptic p-endings. A large number of the analyzed p-endings showed GABA like immunoreactivity. These observations provide evidence that periodontal afferent terminals show very simple and characteristic synaptic arrangements in the trigeminal motor nucleus and that p-endings presynaptic to them may use GABA as a neurotransmitter for presynaptic inhibition.
Animals ; Bite Force ; Dendrites ; gamma-Aminobutyric Acid ; Horseradish Peroxidase ; Jaw ; Mastication ; Neurons ; Neurotransmitter Agents ; Rats* ; Reflex