The present study aimed to asses the total number and distribution of the NADPH-diaphorase-positi... more The present study aimed to asses the total number and distribution of the NADPH-diaphorase-positive non-pyramidal neurons in Ammon's horn and dentate gyrus of rat hippocampal formation. Cell bodies were counted according to the "disector" principle. The total numbers varied from 27 000 to 32 400. In all strains, approximately one third of the NADPH-diaphorase-reactive non-principal cells were found in the dentate gyrus and the remaining two thirds were within the Ammon's horn. Analysis of the dorsoventral differences revealed that approximately 70% of NADPH-diaphorase-positive cells were in the dorsal and 30% in the ventral hippocampus. Distribution of NADPH-diaphorase-reactive cells in the different layers of the dentate gyrus and Ammon's horn was similar in all strains. Double-labelling studies revealed colocalization of NADPH-diaphorase with calretinin, but none with calbindin or parvalbumin. NADPH-diaphorase-positive neurons appear to form the largest chemically identified subpopulation of the GABAergic inhibitory cell population of the hippocampal formation.
The present study aimed to asses the total number and distribution of the NADPH-diaphorase-positi... more The present study aimed to asses the total number and distribution of the NADPH-diaphorase-positive non-pyramidal neurons in Ammon's horn and dentate gyrus of rat hippocampal formation. Cell bodies were counted according to the "disector" principle. The total numbers varied from 27 000 to 32 400. In all strains, approximately one third of the NADPH-diaphorase-reactive non-principal cells were found in the dentate gyrus and the remaining two thirds were within the Ammon's horn. Analysis of the dorsoventral differences revealed that approximately 70% of NADPH-diaphorase-positive cells were in the dorsal and 30% in the ventral hippocampus. Distribution of NADPH-diaphorase-reactive cells in the different layers of the dentate gyrus and Ammon's horn was similar in all strains. Double-labelling studies revealed colocalization of NADPH-diaphorase with calretinin, but none with calbindin or parvalbumin. NADPH-diaphorase-positive neurons appear to form the largest chemi...
Neonatal irradiation reduces the dentate granule cells by 60-80%, and consequently the mossy fibe... more Neonatal irradiation reduces the dentate granule cells by 60-80%, and consequently the mossy fiber projection toward the CA3 and hilar areas decreases. The number of hilar cells diminishes. Thorny excrescences on the dendrites of the CA3 pyramidal cells get smaller both in number (from 20-30 per neuron in normal to 1-6 per neuron after irradiation) and in size. In spite of these morphological changes functional efficacy of the mossy-fiber projection to CA3 pyramidal cells remains sufficient to generate monosynaptic action potentials when stimulated electrically. Inhibitory circuits activated by mossy fiber volleys seem to be unaffected by irradiation. Main biophysical properties of CA3 pyramidal and surviving granule cells remain within the normal range. Further work should determine if efficacy of the mossy fiber projection increases to compensate for the substantial decrease of presynaptic input, or the power of transmission far exceeds the level needed to fire postsynaptic cells ...
Profound decrease of the carnitine acetyltransferase activity (0.08 U/g wet weight; 1.67% of cont... more Profound decrease of the carnitine acetyltransferase activity (0.08 U/g wet weight; 1.67% of control) and carnitine deficiency (total carnitine was 230 nmol/g wet weight in the patient vs 2730 in the controls) was detected in the skeletal muscle of a female paediatric patient. She died of her illness, which included cerebellar symptoms and slight muscle spasticity affecting mainly the lower extremities, at 1 year of age. Histological examination of the autopsy specimens revealed a selective Purkinje cell degeneration in the cerebellum: the cells had abnormal position, were shrunken and decreased in number, and displayed abnormal dendritic trees and fragmented, disorganized axons. Electron microscopy revealed mitochondrial abnormalities in skeletal and cardiac muscle and also in the Purkinje cells. Deletions of the mitochondrial DNA were detected in the muscle in heteroplasmic form (up to 7%). Mainly the ND4-ND4L region was affected, as evidenced by the PCR; however, other regions of...
Jean Piaget's "stage theory" suggests that cognitive development proceeds in discre... more Jean Piaget's "stage theory" suggests that cognitive development proceeds in discrete steps, among which the first is the sensorimotor period that occupies the first two years. In recent years it became clear that an intact and mature hippocampus is necessary for memory formation both in experimental animals and in human. In the present experiments the perinatal morphological development of the human hippocampus was studied to describe structural changes that may correlate with the developmental changes of intellectual growth. Our results suggest that cell formation in the human hippocampus terminates several weeks before birth, but immature cells migrate to their final positions through the first six postnatal months. The newborn hippocampus contains all cell types and cell layers that are characteristic for the adult hippocampus. However, changes of the light microscopic features of the postsynaptic target neurons of hippocampal granule cells indicate that connection...
The case of a female patient with cardio-encephalo-myopathy who died of her illness at one year o... more The case of a female patient with cardio-encephalo-myopathy who died of her illness at one year of age, similarly to her three sisters, is reported. In autopsy samples, like muscle, heart, liver and cerebellum activities of several mitochondrial enzymes were determined. In the skeletal muscle serious decrease of carnitine acetyltransferase was observed (from the normal 4.8 U/g to 0.08 U/g wet weight), while in other tissues this activity was normal. In the muscle activities of several other mitochondrial enzymes were also decreased (cytochrome oxidase, NADH cytochrome C oxidoreductase, citrate synthase), while in other tissues there were no similar changes. Serious distortion was observed in the structure of the majority of mitochondria of muscle and heart by electronmicroscopy. The number of the Purkinje-cells in the cerebellum decreased, and the cells were shrunken, their axons were fragmented and disoriented. Also the structure of the mitochondria was abnormal in the Purkinje-cel...
Acta morphologica Academiae Scientiarum Hungaricae, 1978
H3-thymidine incorporating cells were demonstrated by autoradiography in the developing cortex. B... more H3-thymidine incorporating cells were demonstrated by autoradiography in the developing cortex. Before the 7-8th days labelled cells were distributed throughout the full width of the internal granular layer. Between days 8 to 14 they were found exclusively in the ganglionic layer and were identified as Bergmann-glia. Thyroid hormone treatment brought about an earlier shift of the label to the ganglionic layer indicating an acceleration of Bergmann-glia formation. Since the acceleration coincided with the known accelerating effect of thyroid hormone on granule cell migration, a causal relationship is assumed between Bergmann-glia formation and granula cell migration.
The effect of daily triiodothyronine (T3) treatment (first injection on the day of birth) was stu... more The effect of daily triiodothyronine (T3) treatment (first injection on the day of birth) was studied on the postnatal development of various parts of the rat brain. It was found that the T3 treatment resulted in an increase of the cell multiplication in the external grannular layer of the cerebellum but decreased the cell division or had no significant effect in the periventricular germinal layer and in the polymorph layer of the dentate gyrus. From the 10th day the T3 treatment resulted in a decrease of the cell division in all secondary germinal layers examined. As a reason for this different effect is can be suggested that the triidothyronine acts differently upon the various neuronal and glial precursors or upon the germinal layers producing them.
Basket cells of the dentate gyrus were identified using Nissl (cresyl violet) staining. It has be... more Basket cells of the dentate gyrus were identified using Nissl (cresyl violet) staining. It has been found that the ratio between basket and granule cells is 1:150--210. Only a few glial cells, mainly astroglia, were found in the granular layer of the dentate gyrus. In accordance with earlier data it was found that the granule cells and glial cells originate mainly postnatally, but the basket cells, like the pyramidal cells of the hippocampus, originate prenatally.
Cocaine- and amphetamine-regulated transcript (CART) peptide immunocytochemistry was used to reve... more Cocaine- and amphetamine-regulated transcript (CART) peptide immunocytochemistry was used to reveal cellular localization in the dentate gyrus and in Ammon's horn of the rat and human hippocampal formations. In the rat dentate gyrus, only granule cells were labeled, whereas in humans, only mossy cells of the hilar region expressed CART peptide immunoreactivity. In the rat, CART-positive granule cells were located at the molecular layer border of the granule cell layer and had no features that would distinguish them from other granule cells. The mossy fiber bundle was labeled in the hilus as well as along the entire CA3 area of Ammon's horn. In the human, CART-immunoreactive mossy cells displayed the characteristic thorny excrescences both on their somata and their main dendrites. Axon collaterals of mossy cells could be seen in the hilus and the main axons formed a dense band in the inner molecular layer of the dentate gyrus, suggesting that mossy cells are the principal sou...
International journal of developmental neuroscience : the official journal of the International Society for Developmental Neuroscience, 2008
Oligodendroglial cells differ in their ultrastructural appearance depending on their myelin produ... more Oligodendroglial cells differ in their ultrastructural appearance depending on their myelin producing and maintaining activity. To better understand the relationship between light and electron microscopic features of myelination, myelin formation in the corpus callosum was studied in young postnatal mice. Immunostaining for myelin basic protein (MBP), which has an important role in myelin compaction, was compared with conventional Luxol Fast Blue myelin staining and with electron microscopic images of unlabeled tissue. MBP-immunostaining labeled a few oligodendroglial cells at postnatal day (P)3, and a few axons at P7 in the corpus callosum, below the fronto-parietal somatosensory cortex. By P10 there were more myelinated axons below the somatosensory cortex and the first MBP-immunoreaction appeared in the cingulum: labeling appeared even later in the remaining areas of corpus callosum. Electron microscopy revealed numerous medium oligodendroglial cells at P7 in the corpus callosum,...
Cardiomyocytic apoptosis occurs after cardiopulmonary bypass (CPB) despite the use of perfusion t... more Cardiomyocytic apoptosis occurs after cardiopulmonary bypass (CPB) despite the use of perfusion techniques and cardioplegic solutions. Reactive oxygen species (ROS) cause single-strand DNA breaks and activate nuclear poly(ADP-ribose) polymerase (PARP), which leads to cellular damage. Therefore, the inhibition of PARP might protect cardiomyocytes from oxidative injuries. In this study, experiments were designed to determine whether a PARP inhibitor could decrease the myocardial ischemia/reperfusion injury after cardioplegia-induced global cardiac arrest under CPB, attenuate the appearance of cardiomyocytic apoptosis, and decrease damage from ROS. New Zealand white rabbits (10 in each group) were subjected to total CPB. Rabbits were weaned from CPB and reperfused for 4 h before the hearts were harvested. 3-Aminobenzamide and/or 3-aminobenzoic acid was added to the cardioplegic solution. The ascending aorta was cross-clamped for 60 min while intermittent cold crystalloid cardioplegic s...
Behavioral responses to novelty in an open field and spatial learning in a radial maze with four ... more Behavioral responses to novelty in an open field and spatial learning in a radial maze with four arms out of eight reinforced were tested in male and female CFY and Long-Evans rats. Subsequently, the sizes of the total hippocampi and of various hippocampal cell layers and terminal fields at the midseptotemporal level were measured in Timm-stained sections. No strain differences were found in the open field (except for defecation). In the radial maze, Long-Evans rats showed better spatial reference memory capabilities than rats of the CFY strain. The relative sizes of the intra- and infrapyramidal mossy fiber (IIP-MF) projections did not differ between the strains. Within the more variable CFY strain, a positive correlation between the size of the IIP-MF projection and radial maze performance was found. The absolute sizes of the entire hippocampi and all hippocampal layers at the midseptotemporal level were larger in the CFY strain. The size of the suprapyramidal mossy fiber projection was related to the number of granule cells and to the ratio between granule and CA3 pyramidal cells. In contrast, the size of the IIP-MF projection did not correlate with either of these variables. The results indicate that the size of the mossy fiber projection may be determined mainly by the available postsynaptic surface on the dendrites of CA3 pyramidal neurons. Furthermore, an increased number of granule cells and their larger projection to the apical dendrites of pyramidal neurons does not appear to result in physiological changes with behavioral consequences.(ABSTRACT TRUNCATED AT 250 WORDS)
The present study aimed to asses the total number and distribution of the NADPH-diaphorase-positi... more The present study aimed to asses the total number and distribution of the NADPH-diaphorase-positive non-pyramidal neurons in Ammon's horn and dentate gyrus of rat hippocampal formation. Cell bodies were counted according to the "disector" principle. The total numbers varied from 27 000 to 32 400. In all strains, approximately one third of the NADPH-diaphorase-reactive non-principal cells were found in the dentate gyrus and the remaining two thirds were within the Ammon's horn. Analysis of the dorsoventral differences revealed that approximately 70% of NADPH-diaphorase-positive cells were in the dorsal and 30% in the ventral hippocampus. Distribution of NADPH-diaphorase-reactive cells in the different layers of the dentate gyrus and Ammon's horn was similar in all strains. Double-labelling studies revealed colocalization of NADPH-diaphorase with calretinin, but none with calbindin or parvalbumin. NADPH-diaphorase-positive neurons appear to form the largest chemically identified subpopulation of the GABAergic inhibitory cell population of the hippocampal formation.
The present study aimed to asses the total number and distribution of the NADPH-diaphorase-positi... more The present study aimed to asses the total number and distribution of the NADPH-diaphorase-positive non-pyramidal neurons in Ammon's horn and dentate gyrus of rat hippocampal formation. Cell bodies were counted according to the "disector" principle. The total numbers varied from 27 000 to 32 400. In all strains, approximately one third of the NADPH-diaphorase-reactive non-principal cells were found in the dentate gyrus and the remaining two thirds were within the Ammon's horn. Analysis of the dorsoventral differences revealed that approximately 70% of NADPH-diaphorase-positive cells were in the dorsal and 30% in the ventral hippocampus. Distribution of NADPH-diaphorase-reactive cells in the different layers of the dentate gyrus and Ammon's horn was similar in all strains. Double-labelling studies revealed colocalization of NADPH-diaphorase with calretinin, but none with calbindin or parvalbumin. NADPH-diaphorase-positive neurons appear to form the largest chemi...
Neonatal irradiation reduces the dentate granule cells by 60-80%, and consequently the mossy fibe... more Neonatal irradiation reduces the dentate granule cells by 60-80%, and consequently the mossy fiber projection toward the CA3 and hilar areas decreases. The number of hilar cells diminishes. Thorny excrescences on the dendrites of the CA3 pyramidal cells get smaller both in number (from 20-30 per neuron in normal to 1-6 per neuron after irradiation) and in size. In spite of these morphological changes functional efficacy of the mossy-fiber projection to CA3 pyramidal cells remains sufficient to generate monosynaptic action potentials when stimulated electrically. Inhibitory circuits activated by mossy fiber volleys seem to be unaffected by irradiation. Main biophysical properties of CA3 pyramidal and surviving granule cells remain within the normal range. Further work should determine if efficacy of the mossy fiber projection increases to compensate for the substantial decrease of presynaptic input, or the power of transmission far exceeds the level needed to fire postsynaptic cells ...
Profound decrease of the carnitine acetyltransferase activity (0.08 U/g wet weight; 1.67% of cont... more Profound decrease of the carnitine acetyltransferase activity (0.08 U/g wet weight; 1.67% of control) and carnitine deficiency (total carnitine was 230 nmol/g wet weight in the patient vs 2730 in the controls) was detected in the skeletal muscle of a female paediatric patient. She died of her illness, which included cerebellar symptoms and slight muscle spasticity affecting mainly the lower extremities, at 1 year of age. Histological examination of the autopsy specimens revealed a selective Purkinje cell degeneration in the cerebellum: the cells had abnormal position, were shrunken and decreased in number, and displayed abnormal dendritic trees and fragmented, disorganized axons. Electron microscopy revealed mitochondrial abnormalities in skeletal and cardiac muscle and also in the Purkinje cells. Deletions of the mitochondrial DNA were detected in the muscle in heteroplasmic form (up to 7%). Mainly the ND4-ND4L region was affected, as evidenced by the PCR; however, other regions of...
Jean Piaget's "stage theory" suggests that cognitive development proceeds in discre... more Jean Piaget's "stage theory" suggests that cognitive development proceeds in discrete steps, among which the first is the sensorimotor period that occupies the first two years. In recent years it became clear that an intact and mature hippocampus is necessary for memory formation both in experimental animals and in human. In the present experiments the perinatal morphological development of the human hippocampus was studied to describe structural changes that may correlate with the developmental changes of intellectual growth. Our results suggest that cell formation in the human hippocampus terminates several weeks before birth, but immature cells migrate to their final positions through the first six postnatal months. The newborn hippocampus contains all cell types and cell layers that are characteristic for the adult hippocampus. However, changes of the light microscopic features of the postsynaptic target neurons of hippocampal granule cells indicate that connection...
The case of a female patient with cardio-encephalo-myopathy who died of her illness at one year o... more The case of a female patient with cardio-encephalo-myopathy who died of her illness at one year of age, similarly to her three sisters, is reported. In autopsy samples, like muscle, heart, liver and cerebellum activities of several mitochondrial enzymes were determined. In the skeletal muscle serious decrease of carnitine acetyltransferase was observed (from the normal 4.8 U/g to 0.08 U/g wet weight), while in other tissues this activity was normal. In the muscle activities of several other mitochondrial enzymes were also decreased (cytochrome oxidase, NADH cytochrome C oxidoreductase, citrate synthase), while in other tissues there were no similar changes. Serious distortion was observed in the structure of the majority of mitochondria of muscle and heart by electronmicroscopy. The number of the Purkinje-cells in the cerebellum decreased, and the cells were shrunken, their axons were fragmented and disoriented. Also the structure of the mitochondria was abnormal in the Purkinje-cel...
Acta morphologica Academiae Scientiarum Hungaricae, 1978
H3-thymidine incorporating cells were demonstrated by autoradiography in the developing cortex. B... more H3-thymidine incorporating cells were demonstrated by autoradiography in the developing cortex. Before the 7-8th days labelled cells were distributed throughout the full width of the internal granular layer. Between days 8 to 14 they were found exclusively in the ganglionic layer and were identified as Bergmann-glia. Thyroid hormone treatment brought about an earlier shift of the label to the ganglionic layer indicating an acceleration of Bergmann-glia formation. Since the acceleration coincided with the known accelerating effect of thyroid hormone on granule cell migration, a causal relationship is assumed between Bergmann-glia formation and granula cell migration.
The effect of daily triiodothyronine (T3) treatment (first injection on the day of birth) was stu... more The effect of daily triiodothyronine (T3) treatment (first injection on the day of birth) was studied on the postnatal development of various parts of the rat brain. It was found that the T3 treatment resulted in an increase of the cell multiplication in the external grannular layer of the cerebellum but decreased the cell division or had no significant effect in the periventricular germinal layer and in the polymorph layer of the dentate gyrus. From the 10th day the T3 treatment resulted in a decrease of the cell division in all secondary germinal layers examined. As a reason for this different effect is can be suggested that the triidothyronine acts differently upon the various neuronal and glial precursors or upon the germinal layers producing them.
Basket cells of the dentate gyrus were identified using Nissl (cresyl violet) staining. It has be... more Basket cells of the dentate gyrus were identified using Nissl (cresyl violet) staining. It has been found that the ratio between basket and granule cells is 1:150--210. Only a few glial cells, mainly astroglia, were found in the granular layer of the dentate gyrus. In accordance with earlier data it was found that the granule cells and glial cells originate mainly postnatally, but the basket cells, like the pyramidal cells of the hippocampus, originate prenatally.
Cocaine- and amphetamine-regulated transcript (CART) peptide immunocytochemistry was used to reve... more Cocaine- and amphetamine-regulated transcript (CART) peptide immunocytochemistry was used to reveal cellular localization in the dentate gyrus and in Ammon's horn of the rat and human hippocampal formations. In the rat dentate gyrus, only granule cells were labeled, whereas in humans, only mossy cells of the hilar region expressed CART peptide immunoreactivity. In the rat, CART-positive granule cells were located at the molecular layer border of the granule cell layer and had no features that would distinguish them from other granule cells. The mossy fiber bundle was labeled in the hilus as well as along the entire CA3 area of Ammon's horn. In the human, CART-immunoreactive mossy cells displayed the characteristic thorny excrescences both on their somata and their main dendrites. Axon collaterals of mossy cells could be seen in the hilus and the main axons formed a dense band in the inner molecular layer of the dentate gyrus, suggesting that mossy cells are the principal sou...
International journal of developmental neuroscience : the official journal of the International Society for Developmental Neuroscience, 2008
Oligodendroglial cells differ in their ultrastructural appearance depending on their myelin produ... more Oligodendroglial cells differ in their ultrastructural appearance depending on their myelin producing and maintaining activity. To better understand the relationship between light and electron microscopic features of myelination, myelin formation in the corpus callosum was studied in young postnatal mice. Immunostaining for myelin basic protein (MBP), which has an important role in myelin compaction, was compared with conventional Luxol Fast Blue myelin staining and with electron microscopic images of unlabeled tissue. MBP-immunostaining labeled a few oligodendroglial cells at postnatal day (P)3, and a few axons at P7 in the corpus callosum, below the fronto-parietal somatosensory cortex. By P10 there were more myelinated axons below the somatosensory cortex and the first MBP-immunoreaction appeared in the cingulum: labeling appeared even later in the remaining areas of corpus callosum. Electron microscopy revealed numerous medium oligodendroglial cells at P7 in the corpus callosum,...
Cardiomyocytic apoptosis occurs after cardiopulmonary bypass (CPB) despite the use of perfusion t... more Cardiomyocytic apoptosis occurs after cardiopulmonary bypass (CPB) despite the use of perfusion techniques and cardioplegic solutions. Reactive oxygen species (ROS) cause single-strand DNA breaks and activate nuclear poly(ADP-ribose) polymerase (PARP), which leads to cellular damage. Therefore, the inhibition of PARP might protect cardiomyocytes from oxidative injuries. In this study, experiments were designed to determine whether a PARP inhibitor could decrease the myocardial ischemia/reperfusion injury after cardioplegia-induced global cardiac arrest under CPB, attenuate the appearance of cardiomyocytic apoptosis, and decrease damage from ROS. New Zealand white rabbits (10 in each group) were subjected to total CPB. Rabbits were weaned from CPB and reperfused for 4 h before the hearts were harvested. 3-Aminobenzamide and/or 3-aminobenzoic acid was added to the cardioplegic solution. The ascending aorta was cross-clamped for 60 min while intermittent cold crystalloid cardioplegic s...
Behavioral responses to novelty in an open field and spatial learning in a radial maze with four ... more Behavioral responses to novelty in an open field and spatial learning in a radial maze with four arms out of eight reinforced were tested in male and female CFY and Long-Evans rats. Subsequently, the sizes of the total hippocampi and of various hippocampal cell layers and terminal fields at the midseptotemporal level were measured in Timm-stained sections. No strain differences were found in the open field (except for defecation). In the radial maze, Long-Evans rats showed better spatial reference memory capabilities than rats of the CFY strain. The relative sizes of the intra- and infrapyramidal mossy fiber (IIP-MF) projections did not differ between the strains. Within the more variable CFY strain, a positive correlation between the size of the IIP-MF projection and radial maze performance was found. The absolute sizes of the entire hippocampi and all hippocampal layers at the midseptotemporal level were larger in the CFY strain. The size of the suprapyramidal mossy fiber projection was related to the number of granule cells and to the ratio between granule and CA3 pyramidal cells. In contrast, the size of the IIP-MF projection did not correlate with either of these variables. The results indicate that the size of the mossy fiber projection may be determined mainly by the available postsynaptic surface on the dendrites of CA3 pyramidal neurons. Furthermore, an increased number of granule cells and their larger projection to the apical dendrites of pyramidal neurons does not appear to result in physiological changes with behavioral consequences.(ABSTRACT TRUNCATED AT 250 WORDS)
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