ABSTRACT
The excitotoxic effect of kainic acid on dendrites and neuronal cell bodies of hippocampus and dentate gyrus was studied with time (1, 4, 8, 16 hours, 2, 7, 14 days) light and electron microscopically by intraperitonial injection into rat. The results obtained were as follows. 1) The acute dendrotoxic effect was observed as laminar pattern of swelling along pyramidal cell body layer and dendritic fields and was most prominently at 2-4 hours after kainic acid injection. In ultractructural study, the acute change occurred in dendrites of pyramidal cells in hipocampus because the synapses between nerve terminals and swollen components were not destroyed and remained intact and, identified the swollen structures as dendrites. So, it was obvious from the results that the acute change by kainic acid was osmolysis and was continued till initial 4 hours but was finally faded out. 2) The distribution of kainic acid receptor within hippocampus was different because the prominent dendritic swelling occurred in proximal basilar dendritic field of CA 3 and 4 and the proximal and distal basilar dendritic fields of CA 1 and 2, and no change was observable in dentate granule cell. The sensitivity of hippocampal dendritic fields to kainic acid could be put in decreasing order as CA3, CA4, CA1, CA2 and dentate granule cell 3) With the elapse of time, the acute change disappeared and pyramidal cells began to degenerate by the chronic reaction about 7 days after kainic acid injury, and the pyramidal cell density in CA regions greatly decreased. Almost all pyramidal cells degenerated the dentate granule cells were not affected to kainic acid throughout the time. In conclusions, hippocampal neurons were postulated to be very sensitive to kainic acid, and in contrast to the gradual disappearance of acute change within several hours, the degeneration of pyramidal neurons by chronic change was developed within several days regardless of acute change.
Subject(s)
Animals , Rats , Brain , Dendrites , Dentate Gyrus , Hippocampus , Kainic Acid , Neurons , Pyramidal Cells , Receptors, Kainic Acid , SynapsesABSTRACT
No abstract available.
Subject(s)
Animals , Rats , Cerebral Cortex , Glutamic Acid , Glycine , Kynurenic Acid , PerfusionABSTRACT
The ultrastructure of the excitotoxic lesion similar to that occurring in the degenerative neuronal disease was produceby stereotaxic injections of 1 nmol and 10 mnol of kainic acid nto the corpus striatum of adult rat brain There were rnarked swellings in the neuronal dendrites at injected sites. Neurotubules and neurofilarnents were disrupted as and amorphous materials and scattered throughout the interior of distended dendrites. Internal cristae and membranes of mitochondria were destroyed with the loss of integrity of intracellular organelles. Disruption of cellular and nuclear membranes occurered in severe cases. But there was no apparent pathologic change in the other structure, ie, synapses, presynaptic and postsynaptic parts, axons and glial cells. The synapses between dendrites and axon terminals were not destroyed despite of marked distension of dendrites. The local administration of excitatory amino acid into the brain caused the destruction of dendrites and neuronal cell bodies, but axons and axon terminals were intact With the lapse of time, axons and axon terminals from the destroyed neuron degenerate Therelore stereotaxic injection of excitatory amino acid into the brain may provldes a method of investigating neuronal connectivity.
Subject(s)
Adult , Animals , Humans , Rats , Axons , Brain , Corpus Striatum , Dendrites , Excitatory Amino Acids , Kainic Acid , Membranes , Mitochondria , Neuroglia , Neurons , Nuclear Envelope , Organelles , Presynaptic Terminals , SynapsesABSTRACT
The primitive erythroblasts in 21 cases of embryonic hearts from 4 to 9 weeks of gestation were studied with a light microscope. The nuclear diameter, the motosis, and the loss of nuclei of the primitive erythoblasts were analyzed quantitatively. The results obtained were as follows. 1. At 4 weeks of gestation, the blood cells consisted of proerythroblasts, along with basophilic polychromatophilic primitive erythroblasts. The nuclear diameter ranged from 3.20 µm to 9.20 µm, but the main range was from 4.20 µm to 6.00 µm. It was revealed that 9.50% had diameter of more than 6 µm. 2. At the fist half of the 7 week gestation when hepatic hemopoiesis developed, the blood cells consisted of basophilic, polychromatophilic, and eosinophilic erythroblasts. Cells of more than 6 µm in nuclear diameter were about 1.10% and thereafter gradually disappeared. The range of the nuclear diameters was from 2.60 µm to 7.00 µm, while a range from 3.40 µm to 5.20 µm wqs the main. The proportion of cells less than 4 µm in nuclear diameter was 39.58% and thereafter rapidly increased. 3. From the second half of 7 weeks to 9 weeks of gestation, the erythrocytes originating from hepatic hemopoiesis increasingly replaced the circulating primitive erythroblasts, which became mature during this time. The erythrocytes showed 72.88% at 9 weeks of gestation. The proportions of cells less than 4 µm in nuclear diameter in the first and second haIves of 8 weeks and 9 weeks were 52.73%, 80.02%, and 89.09%, which represented the rapid destruction of nuclei. 4. Mitosis in the primitive erythroblasts occurred principally up to the early 6th weeks, and very weakly at 8 weeks. 5. As the crown-rump length increased, the average nuclear diameter decreased very significantly (P<0.01, y=-0.2811X + 0.3171). The results suggest that distrilbution of the nuclear diameter, the maturity, the rate of nuclear loss, and the mitotic figure offer credible data for estimating embryonic age.
Subject(s)
Humans , Pregnancy , Basophils , Blood Cells , Crown-Rump Length , Embryonic Structures , Eosinophils , Erythroblasts , Erythrocytes , Heart , MitosisABSTRACT
The branches of the axillary artery have been studied in 38 Korean female cadavers. 1. The superior thoracic artery arose from the first part and the second part of the axillary artery in 84% of sides. 2. The thoracoacromial artery arose from the axillary artery near the superomedial border of the axillaly artery more often (91%) than from any other source. 3. The lateral thoracic artery was found on 64% of the sides as a main axillary artery, usually arising from the second part of the axillary artery(61%). It arose from the subscapular artery in 28%. 4. The subscapular artery was seen as the lagrgest of the axillary artery. It arose from the second part (42%) and the third (58%) of the axillary artery. 5. The posterior circumflex humeral artery was a direct branch of the third part of axillary artery in 37% of sides. In 21% fo sides the posterior circumflex humeral artery arose by a common stem from the third part of the axillary artery. In 33% of sides the posterior circumflex humeral artery arose from the subscapular artery. 6. The anterior circumflex humeral artery was found more constantly at the third part of the axillary artery than the posterior circumflex humeral artery was. It arose from a direct branch of the third part of the axillary artery in 70% of sides.
Subject(s)
Female , Humans , Arteries , Axillary Artery , Cadaver , Thoracic ArteriesABSTRACT
The stature, span, lower limb length, sitting height, head length and head breadth of 411 Korean elementary school girls ranging from 7 to 10 years of age were measured biometrically and the indices among all of the items were calculated to investigate the physical growth status. The following conclusion have been obtained. 1. The average statures were 117.40cm in 7, 122.72cm in 8, 126.76cm in 9 and 132.92cm in 10 years of age groups, and the annual average stature growth was 5.17cm. 2. The average spans were 113.12cm in 7, 118.70cm in 8, 124.26cm in 9, 130.46cm in 10 years of age groups, and the annual average span growth was 5.78cm. 3. The average lower limb lengths were 62.96cm in 7, 66.80cm in 8, 69.09cm in 9 and 73.13cm in 10 years of age groups, and the annual average lower length growth was 3.39cm 4. The average sitting heights were 65.82cm in 7, 68.56cm in 8, 70.18cm in 9 and 73.13cm in 10 years of age groups, and the annual average sitting height growth was 2.43cm. 5. The average body weights were 21.22kg in 7, 24.13kg in 8, 25.54kg in 9 and 29.27kg in 10 years of age groups, and the annual average body weight growth was 2.68kg. 6. The average head lengths were 16.29cm in 7, 16.38cm in 8, 16.47cm in 9 and 16.60cm in 10 yeras of age groups, and the annual average head length growth was 0.10cm. 7. The average head breadth were 14.50cm in 7, 14.65cm in 8, 14.67cm in 9 and 14.81cm in 10 years of age groups, and the annual average head breadth growth was 0.10cm. 8. While both relative span and lower limb length increased with age and the relative sitting height slightly decreased with age. 9. The relative body weight increased with age. 10. The head type depended on cephalic index was belonged to hyperbrachycephaly, and showed no differrences with age in all of the groups. 11. The relative span was over 96 in all age groups, and the value increased slightly with age. 12. The average annual growth showed remarkable high value between 9 to 10 years of age in the items of stature, span, lower limb length, sitting height and body weight.