ABSTRACT
This study was designed to clarify the cytotoxic effects of 6-hydroxydopamine (6-OHDA) on the dopaminergic neurons and astrocytes in the dorsal raphe nucleus (DRN), and to investigate neurodegenerative changes by immuno-histochemistry. Adult male rats (Sprague-Dawley strain) weighing from 250 to 350 g were used as experimental animals. 6-OHDA (100 micrometer dissolved in 0.1% ascorbic acid) was injected into the lateral ventricle of the rat brain with the Hamilton syringe. The control rats were treated with the similar volume of 0.1 % ascorbic acid. The rats were sacrificed at the 3rd, 5th, 10th and 20th day, respectively, after the injection of 6-OHDA. The cytotoxicity of 6-OHDA resulted in severe neurodegeneration of the dopaminergic neurons in the DRN. In the 3rd day, the dopaminergic fibers were dilated. In the 5th and 10th days, the dopaminergic fibers were depleted, and dopaminergic cell bodies were shrunken. In the 20th day, the dopaminergic cell bodies were almost completely disappeared. Astroglial reactions induced by 6-OHDA were also observed in the DRN. In the 5th day, astrocytes were significantly increased as compared with that of the control value. The value were reached at its maximum by the 20th day. Based on the present results, it suggests that 6-OHDA may act as a specific neurotoxin to dopaminergic neurons in the DRN, and induce severe neurodegenerative changes. Also, it suggests that the astroglial reaction in the DRN is gradually activated during the neurodegerative changes.
Subject(s)
Adult , Animals , Humans , Male , Rats , Ascorbic Acid , Astrocytes , Brain , Dopaminergic Neurons , Lateral Ventricles , Oxidopamine , Raphe Nuclei , SyringesABSTRACT
This study was designed to clarify the cytotoxic effects of 5, 7-dihydroxytryptamine (5, 7-DHT) on the serotonergic neurons in the dorsal raphe nucleus, and to investigate the glial reaction during the neurodegenerative changes by light and electron microscopy. Adult male rats (Sprague-Dawley strain) weighing from 250 g to 350 g each were used as experimental animal. 5, 7-DHT (200 mg dissolved in 0.9% NaCl) was injected into the lateral ventricle of the rat brain with the Hamiton syringe fixed on stereotaxic apparatus. The control rats were given with the similar volume of 0.9% NaCl. The rats were sacrified on the 1st, 3rd, 5th, 10th and 20th day after the injection of 5, 7-DHT. The results were as follows : Glial reactions induced by 5, 7-DHT were also observed in DRN. In early experimental stage, microglial reactions prevailed, whereas astroglial reactions were prevailing in later stage. In addition, microglial cells phagocytosed and removed the degenerated cells. However, astrocytes in DRN did not show phagocytotic activities such as microglial cells. Based on the results, author thought that 5, 7-DHT act as a specific neurotoxin to serotonergic neurons in DRN, and induces severe neurodegenerative changes. The glial reactions in DRN are activated during the neurodegerative changes, and show characteristic patterns of glial reactions.
Subject(s)
Adult , Animals , Humans , Male , Rats , Astrocytes , Brain , Lateral Ventricles , Microglia , Microscopy, Electron , Neuroglia , Raphe Nuclei , Serotonergic Neurons , SyringesABSTRACT
This study was designed to clarify the cytotoxic effects of 5, 7-dihydroxytryptamine (5, 7-DHT) on the serotonergic neurons in the dorsal raphe nucleus, and to investigate the glial reaction during the neurodegenerative changes by light and electron microscopy. Adult male rats (Sprague-Dawley strain) weighing from 250 g to 350 g each were used as experimental animal. 5, 7-DHT (200 microgram dissolved in 0.9% NaCl) was injected into the lateral ventricle of the rat brain with the Hamiton syringe fixed on stereotaxic apparatus. The control rats were given with the similar volume of 0.9% NaCl. The rats were sacrified on the 1st, 3rd, 5th, 10th and 20th day after the injection of 5, 7-DHT. The results were as follows : The cytotoxicity of 5, 7-DHT resulted in severe neurodegenerations of the serotonergic neurons. Most degenerated cells mainly showed necrotic findings, but a few of them exhibited apoptotic features. That is, in early stage of this experiment, the degenerated cells showed edematic changes of cytoplasm, but their nuclei were relatively seen intact. In late stage, the cells showed dark degenerative changes both in their cytoplasm and nuclei. Thereafter the cells were autolysed or phagocytosed by neighboring glial cells. Based on the results, author thought that 5, 7-DHT act as a specific neurotoxin to serotonergic neurons in DRN, and induces severe neurodegenerative changes. The glial reactions in DRN are activated during the neurodegerative changes, and show characteristic patterns of glial reactions.
Subject(s)
Adult , Animals , Humans , Male , Rats , Brain , Cytoplasm , Lateral Ventricles , Microscopy, Electron , Neuroglia , Raphe Nuclei , Serotonergic Neurons , SyringesABSTRACT
The effects of dehydration on vasopressin and oxytocin immunoreactive neurons in the hypothalamus was investigated by using a immunohistochemistry. Adult Mongolian gerbil[Meriones unguiculates] were deprived of drinking water. Dehydrated animals were sacrificed on the 7th, 14th and 21st day of water retriction. The results are as follows : 1. The body weights were decreased about 1.8% daily. On the 21st day of dehydration, they were shown up to 45% compare to the control. 2. In the hypothalamus of the control group, majority of vasopressin and oxytocin immunoreactive neurons were located in the supraoptic and paraventricular nuclei. 3. Changes due to dehydrated stimulation were mainly observed in vasopressin immunoreactive neurons. And these changes in supraoptic nuclei were more severe than those in paraventricular nucleus. Size of vasopressin immunoreactived cells and of areas were increased as to proceed the dehydration. The numbers of those were increased on the 7th day of dehydration, and then they were continously decreased. 4. Although oxytocin immunoreactive neurons were slightly changed in numbers during dehydration, they were not shown conspicuous changes compare to vasopressin immunoreactive neurons. Thus it is appeared that vasopressin secretory neurons in the hypothalamus of Mongolian gerbil are affected by osmotic stress induced dehydration while oxytocin neurons may be affected by other factors.
Subject(s)
Adult , Animals , Humans , Body Weight , Dehydration , Drinking Water , Gerbillinae , Hypothalamus , Immunohistochemistry , Neurons , Osmotic Pressure , Oxytocin , Paraventricular Hypothalamic Nucleus , Supraoptic Nucleus , Vasopressins , WaterABSTRACT
No abstract available.
Subject(s)
Animals , Rats , Brain , Corpus Striatum , Neurons , NeuropeptidesABSTRACT
This is a case of synovial chondromatosis involving the left knee joint of a forty one year old man. Chief complaints were gradual development of pain and limitation of knee joint motion of about 10 years duration. K-ray study revealed a single radio-opaque loose body filling the joint cavity. This body, measuring about 3×2×2cm, was removed surgically and found to have a pedicle from the synovial membrane, consisting of fat and fibrous tissue. The diagnosis of synovial chondromatosis was confirmed by pathological study. The postoperative course was uneventful and three months after the operation, the range of motion of the affected knee joint was good.
Subject(s)
Chondromatosis, Synovial , Diagnosis , Joints , Knee Joint , Knee , Range of Motion, Articular , Synovial MembraneABSTRACT
Ca45 resorption and incoporration into albino rat-bones in tissue culture was considered in studying the pathogenesis of osteoporosiscaused by cotinued administration of glucocorticoid, hydrocortisone succinate. 18-day old tibias were cultured in a chemically defined media, (BGJb). Hydrocotisone showed no effect on Ca45 resorption and little increase of Ca45 incorporation into bone. This may suggest that hydrocortisone produces osteoporosis not by direct effect but by secondary effects on calcium metabolism.
Subject(s)
Rats , Animals , Bone Development , Bone and Bones/embryology , Bone and Bones/metabolism , Calcification, Physiologic/drug effects , Calcium/metabolism , Calcium Radioisotopes , Hydrocortisone/adverse effects , Hydrocortisone/pharmacology , Osteoporosis/chemically induced , Tibia , Culture TechniquesABSTRACT
Since Duhamel (1739), numerous experimental studies on the longitudinal growth of growing long bone have been reported. In Hales(1747) experience, growing long bone showed overgrowth after drilling in the tibia of chickens. David(1924) observed the fact that various degrees of shortening disappeared within 15 months after fracture of the femur in children and he concluded that fractures in children should be treated with the caution that the growing long bone has a tendency to increase in length after injury. Bisgard(1936) concluded that shortening from overriding of fragments in fractured extremities of children will frequently, but not invariablly, become partially or totally eliminated by the acceleration of growth which incidentaIly results from the inflammatory process, incited by trauma and fracture repair. Hass(1926) reported that interstitial proliferation of osseous tissue plays no part in the elongation of a growing bone, either in the mature bone or the young osteoid tissue bordering on the epiphyseal cartilage plate, and length growth of bone is entirely dependant on the purposeful multiplication of cartilage cells of the epiphyseal cartilage plate. Ham(1952) reported that the growth of long bone depends upon the interstitial growth of cartilage. This study was initiated to investigate the effects of fractures in the longitudinal bone growth of growing bone. Artificial fractures were made at two different sites in the diaphysis of the tibia in young rabbits. The operation for artificial fracture was performed under general anesthesia with ether. The type of fracture was an incomplete one, leaving a part of the posterior cortex of the tibia, in order to prevent the displacement of fractured fragments. In all of the cases, no cast immobilization was applied. After the fractures, follow up observations were made weekly till the 4th week, and thereafter at two week intervals, with roentgenographic, lethal measurement and histological examination. The results were as follows; 1) Longitudinal bone growth was increased from fracture of the diaphysis of growing long bone. 2) Compared with the control limb, tendency to overgrowth of growing bone was noted from the first week after the operation. 3) In follow up measurements, no growth inhibition was observed till the 10th week after the operation, but, thereafter, a tendency to reduce the proliferation of cartilage cells was noted. 4) In cases of fracture of the mid 1/3, the gorwing activity in the epiphyseal plate was increased more than from proximal 1/3 fractures. 5) The bony growth, accelerated by fractures in diaphysis of growing long bone without displacement was transient, and the prolonged overgrowth was compensated by the reduction of growing activity and premature closure of the epiphysis.