Chemo-architectonic studies in a submammalian brain. Adenosine triphosphatase and simple esterase in the diencephalon and mesencephalon.

The present report deals with the histo-enzymological mapping of adenosine triphosphatase and simple esterase in the diencephalon and mesencephalon of Uromastix hardwickii. The enzymatic make-up, in both cases, does not differ markedly in the various nuclei; few variations, of course, occur in some midbrain areas like pretectal nuclei. The latter are intensely positive for ATPase, while these nuclei are moderate to simple esterase. Nevertheless, one of the most interesting results pertaining to simple esterase activity is of a high order in the fiber tracts in comparison to ATPase. The other interesting feature relates to the fact that generally intensely positive nuclei, in ATPase preparations, are those which have extensive efferent fibres. The metabolic significance of high degree of ATPase activity vis-a-vis extensive efferent connections has been exhaustively discussed, besides the possible significance of the general data obtained.     

Studies on ribonucleic acid and homopolyribonucleotide formation in neuronal, glial and liver nuclei

1. Various types of nuclear preparations, with different ratios of neuronal to glial nuclei, were isolated from guinea-pig cerebral grey matter and ox cerebral grey matter and white matter. Conditions appropriate for the separate assay of RNA and poly A formation were described. Comparative rates of RNA and poly A formation were studied in cerebral and liver nuclei. 2. RNA polymerase activity per nucleus is higher in neuronal nuclei than in glial nuclei. In liver nuclei, the activity is much lower than in cerebral nuclei. The physical relationship between RNA polymerase and deoxyribonucleoprotein seems to differ in neuronal, glial and liver nuclei. 3. Poly A polymerase activity in liver nuclei is selectively activated by Mn(2+) and inhibited by GTP, CTP and UTP. On a DNA basis, the activity in an aggregate enzyme is the same as in intact nuclei. Poly A polymerase activity per nucleus is much higher in liver nuclei than in neuronal nuclei. Glial nuclei show an intermediate activity. 4. It is suggested that, in neuronal nuclei, the synthesis of RNA is more prominent than that of poly A under conditions where both polymers are formed simultaneously. This contrasts with liver nuclei, where more poly A is made than RNA. 5. In neuronal nuclei, the rate of CTP incorporation is much higher than in glial and liver nuclei. This incorporation is most probably due to poly C synthesis.     

Histochemically demonstrable esterase activity in the hypothalamus of the developing rat

Summary The distribution of the acetylcholinesterase, non-specific cholinesterase and non-specific esterase activity has been investigated histochemically in the hypothalamic neurons during the ontogenic development of the rat.Acetylcholinesterase activity is located in the supra-optic and para-ventricular nuclei mostly, but some activity is present in the other nuclei and in the median eminence of the adult rat, as well. The supra-chiasmatic neurons are always negative. The activity of non-specific cholinesterase was encountered in the endothelial cells of the capillaries, in the glia and in the ependymal cells especially around the supra-optic and para-ventricular neurons. The localization of the non-specific esterase was similar to that of the non-specific cholinesterase, but in addition activity is seen in the supra-optic and para-ventricular perikarya, in the parvo-cellular neurons of the tuberal area and in the median eminence. No sexual differences were seen in the distribution of the estrase activity.The appearance of acetylcholinesterase took place already before birth. At about the 16th post-coital day the area from which the arcuate and ventro-medial nuclei will differentiate was positive for acetylcholinesterase. A strong activity in these nuclei was observed during the critical period of the sexual differentiation of the rat hypothalamus (0–10 postnatal days). In the development of the non-specific cholinesterase and esterase no similar variation was seen. Acetylcholinesterase and non-specific esterase were seen in the neurosecretory nuclei before birth, non specific cholinesterase after birth, and non-specific esterase in the parvo-cellular neurons during the first post-natal week.Supported by a grant from The Finnish Medical Society Duodecim.     

Structural organization of amygdaloid brain complex of the rat

Amygdala belong to the system of basal nuclei of telencephalon. Amygdala are a complicated structure based on both principles of grey matter organization: nuclear and screen-type, on its territory. Authors investigate into the structure of Amygdala using theory of Zavarzin A. As the result of this study, a classification of components of Amygdala into nuclei, paleocortical and intermediate formations, has been developed.     

RIBONUCLEASE ACTIVITIES IN VARIOUS CLASSES OF NUCLEI FROM BOVINE CEREBRUM

Abstract— Nuclei of adult bovine cerebrum were separated by dissection of grey matter from white matter and discontinuous sucrose gradient centrifugation, into neuron, astrocyte-enriched and oligodendrocyte fractions. The activities of alkaline and acidic RNAses were determined in the different nuclei types. The acidic and alkaline RNAse activities of the neuronal nuclei were much higher than those of the glial nuclei. In each type of nuclei the acidic RNAse activity was lower than the measured alkaline RNAse activity.     

Histochemical studies of monoamine oxidase of the brain of rodents

Summary MAO of the brain was investigated histochemically in mice, rats, guinea pigs and rabbits. Fresh frozen sections were subjected to the tryptamine-tetrazolium method by Glenner, Burtner and Brown (1957).MAO activity of the brain of 4 animal species is generally similar with respect to its pattern of distribution. However, the intensity of enzyme action of the brain as a whole differs somewhat in animal species, being highest in guinea pigs, intermediate in rats and lowest in mice and rabbits. The enzyme action occurs mainly in the neuropil of the cerebral grey matter, while weak or negative activity is generally observed in the white matter excepting the tractus retroflexus of Meynert.The marked activity is encountered in the interpeduncular nucleus, locus coeruleus, area postrema, dorsal nucleus of the vagus nerve, hypothalamus, habenular nuclei and midline nuclear group of the thalamus, nucleus of the brachium conjunctivum, and central grey matter. The enzyme activity is weak or negative in the neocortex, striatum, mamillary body, thalamic nuclei (excepting the habenula and midline nuclear group), subthalamic nucleus, substantia nigra, red nucleus and nuclei of the somatic cranial nerves.The possible function and significance of MAO in the brain were discussed particularly by comparing the sites of this enzyme with those of succinic dehydrogenase and cytochrome oxidase, and the inverse relation between these enzymes was suggested.     

Species variation in the localisation of esterases in the cerebellar cortex of mouse and bat

A comparative study of the distribution of a simple esterase and acetylcholinesterase in the cerebellar cortex of mouse and bat has been made. The Purkinje layer is intensely positive for simple esterase in both species. The granular and molecular layers showed mild to moderate activity in mouse and intense activity in bat. Acetylcholinesterase in cerebellar layers of bat is more intense than in mouse. In bat cerebellum, acetylcholinesterase is observed in the dendrites of Purkinje cells, but not in their cell bodies. Acetylcholinesterase was not found in Purkinje cells of mouse.     

Histochemical distribution of acetylcholinesterase and simple esterases in the brain of squirrel monkey (Saimiri sciureus)

Summary The distribution of acetylcholinesterase (AChE) and simple esterases (SE) has been investigated in 15 thick fresh frozen sections of the squirrel monkey brain. Simple esterases are cellular enzymes, found in locations similar to those of acid phosphatase (AC), although not as abundantly. The neuropil in most of the nuclei of the brain shows stronger SE activity compared to the AChE reaction. The AChE activity is strong in nucleus caudatus and putamen, and appreciable quantities of this enzyme are found in nucleus fasciculus diagonalis band of Broca, habenular complex, nucleus interpeduncularis, cranial nerve nuclei, gray layers of colliculus superior, griseum pontis, nuclei olivaris inferior, cuneatus, gracilis, etc. The nucleus interpeduncularis has proved very interesting histochemically because it is rich in AChE and SE, as well as acid phosphatase, monoamine oxidase and lactic dehydrogenase. In the area postrema, the neurons give stronger SE activity than the parenchymal cells, while the AChE activity in both types of cells is similar. The molecular layer of cerebellum is stronger in AChE compared to SE, whereas the Purkinje cells and granule cells are strong in SE and show only negligible AChE activity. The lining cells of the choroid plexus, in addition to the ependymal cells, demonstrate a negligible to mild AChE reaction in comparison to moderately strong simple esterase activity. The significance of these observations has been discussed.This work has been carried out with the aid of Grant No. 00165 from the Animal Resources Branch, National Institute of Health and a grant (NGR-11-001-016) from The National Aeronautics and Space Administration. Thanks are due to Mrs. M. J. Nimnicht and Miss M. E. Rogero for their technical help.     

Frontal White Matter Volume Is Associated with Brain Enlargement and Higher Structural Connectivity in Anthropoid Primates

Previous research has indicated the importance of the frontal lobe and its ‘executive’ connections to other brain structures as crucial in explaining primate neocortical adaptations. However, a representative sample of volumetric measurements of frontal connective tissue (white matter) has not been available. In this study, we present new volumetric measurements of white and grey matter in the frontal and non-frontal neocortical lobes from 18 anthropoid species. We analyze this data in the context of existing theories of neocortex, frontal lobe and white versus grey matter hyperscaling. Results indicate that the ‘universal scaling law’ of neocortical white to grey matter applies separately for frontal and non-frontal lobes; that hyperscaling of both neocortex and frontal lobe to rest of brain is mainly due to frontal white matter; and that changes in frontal (but not non-frontal) white matter volume are associated with changes in rest of brain and basal ganglia, a group of subcortical nuclei functionally linked to ‘executive control’. Results suggest a central role for frontal white matter in explaining neocortex and frontal lobe hyperscaling, brain size variation and higher neural structural connectivity in anthropoids.     

Modeling of esterase production from Saccharomyces cerevisiae

A suitable simple model tested by experiments is required to address complex biological reactions like esterase synthesis by Saccharomyces cerevisiae. Such an approach might be the answer to a proper bioprocessing strategy. In this regard, a logistic model for esterase production from Saccharomyces cerevisiae has been developed, which predicts well the cell mass, the carbon source (glucose) consumption, and the esterase activity. The accuracy of the model has been statistically examined by using the Student's t-test. The parameter sensitivity analysis showed that all five parameters (microm, Ks, Xm, Yx/s, and Yp/x) have significant influence on the predicted values of esterase activity.     

REGIONAL AND SUBCELLULAR DISTRIBUTION OF AMINOTRANSFERASES IN RAT BRAIN

Abstract— Aminotransferase activity was measured in various areas of the nervous system of the rat (cortical grey matter, midbrain, corpus callosum, spinal cord and sciatic nerve) and in subcellular fractions of rat brain (nuclei, mitochondria and cytosol). Activity was low or absent in the sciatic nerve relative to that in the other areas, with the exception of incubation of glutamate with oxaloacetate (25 per cent of the activity found in brain) and of asparagine with 2-oxoglutarate (65 per cent of the activity found in brain). The distribution of enzymic activity was not homogeneous; alanine-2-oxoglutarate aminotransferase was highest in cortical grey matter; leucine- and GABA-2-oxoglutarate aminotransferases were highest in midbrain. Incubation of phenylalanine or tyrosine with 2-oxoglutarate gave similar activities in grey matter and midbrain. Activity generally was higher in the grey matter than in corpus callosum or spinal cord. However, incubations of methionine with 2-oxoglutarate, or glutamine with glyoxylate, gave similar activities in the three areas studied from the brain, whereas incubations of glutamate with glyoxylate gave highest activity in the corpus callosum. Only incubations of asparagine with 2-oxoglutarate, and glutamate with glyoxylate, gave significant activity in the nuclear subcellular fraction. Aminotransferase activity of phenylalanine, tyrosine or GABA with 2-oxoglutarate, or ornithine or glutamine with glyoxylate, was localized to mitochondria. The remaining reactions studied (glutamate with oxaloacetate; leucine, alanine, methionine or asparagine with 2-oxoglutarate and glutamate with glyoxylate) demonstrated activity in both the mitochondrial fraction and the soluble supernatant fraction.     

New Developments and Applications of the MP2RAGE Sequence - Focusing the Contrast and High Spatial Resolution R1 Mapping

MR structural T1-weighted imaging using high field systems (>3T) is severely hampered by the existing large transmit field inhomogeneities. New sequences have been developed to better cope with such nuisances. In this work we show the potential of a recently proposed sequence, the MP2RAGE, to obtain improved grey white matter contrast with respect to conventional T1-w protocols, allowing for a better visualization of thalamic nuclei and different white matter bundles in the brain stem. Furthermore, the possibility to obtain high spatial resolution (0.65 mm isotropic) R₁ maps fully independent of the transmit field inhomogeneities in clinical acceptable time is demonstrated. In this high resolution R₁ maps it was possible to clearly observe varying properties of cortical grey matter throughout the cortex and observe different hippocampus fields with variations of intensity that correlate with known myelin concentration variations.     

Expression of signaling molecules associated with apoptosis in human ischemic stroke tissue

There is growing evidence that, because of the highly significant differences in gene activation/protein expression between animal models of stroke and stroke patients, the current treatment strategies based on animal stroke models have been unsuccessful. Therefore, it is imperative that the pathobiology of human stroke be studied. As a first step here, Western blotting and immunohistochemistry were employed to examine expression and tissue localization of key apoptotic proteins in infarct and peri-infarcted (penumbra) from grey and white matter in human postmortem tissue of 18 patients who died between 2 and 37 d after stroke caused by large vessel disease. The contralateral hemisphere was used as a control. JNK1, JNK2, and p53 were upregulated in the majority of samples, whereas Bcl-2, caspase-3, active caspase-3, phosphorylated p53 (p-p53), phosphorylated JNk1 (p-JNK1), and phosphorylated JNK2 (p-JNK2) were upregulated in approximately half of the samples. JNK1 expression was positively correlated with JNK2 expression in grey and white matter infarct and penumbra, whereas active caspase-3 levels were positively correlated with p-JNK2 levels in grey and white matter infarct. Using indirect immunoperoxidase staining of paraffin-embedded sections, active caspase-3 was found in infarcted neurons that co-localized with TUNEL-positive cells. p-JNK localization in the nuclei of TUNEL-positive cells with the morphological appearance of neurons from infarct and penumbra was also demonstrated. The use of Kaplan Meier survival data demonstrated that the presence of Bcl-2 in penumbra of grey matter correlated significantly with shorter survival (p=0.006). In conclusion, the present study has identified significantly altered expression of apoptotic proteins in human stroke tissue and shown that the presence of Bcl-2 in penumbra of grey matter has prognostic value. It is tempting to suggest that further studies of apoptotic proteins in human stroke may lead to identification of novel targets for drug discovery.     

Molecular forms of acetylcholinesterase present in the white and grey matter of pig brain

Extraction of the white matter of pig brain with EDTA, lysolecithin or Triton X-100 gave poor yields of soluble acetylcholinesterase although these agents had proved effective at solubilizing the enzyme in the grey matter. This finding, together with the observation that the strong detergent sodium deoxycholate, was needed to solubilize the enzyme, shows that it is more difficult to remove acetylcholinesterase from the white matter of brain than from the grey. This could mean that the enzyme in the white matter is more firmly bound to the membrane than the enzyme in the grey matter.The difference in binding of the enzyme from the two regions of the brain is also reflected in the affinity chromatography experiments which showed a lower recovery for the acetylcholinesterase of white matter compared with the enzyme from grey matter.Starch-block electrophoresis of acetylcholinesterase showed a single negatively charged peak of activity for both the naturally soluble and the deoxycholate solubilized preparations. The presence of only one form on electrophoresis suggests that the molecular species of acetylcholinesterase do not arise from differences in charge.Sucrose density gradient centrifugation of the two preparations from white matter gave a single peak of activity with a sedimentation constant of about 10 S. This corresponds closely to the major species of molecular weight 260,000 detected by gradient gel electrophoresis. Other forms detected in both enzyme preparations by gradient gel electrophoresis were species with molecular weights of 660,000, 180,000, 130,000 and 115,000. The significance of these species in terms of the formation of oligomers is discussed.A comparison was made with the corresponding preparations of acetylcholinesterase from the grey matter and the results showed that acetylcholinesterase from the white and grey matter of pig brain were very similar. The exception to this was the species with a molecular weight of 68,000 which was present in the grey but not the white matter of pig brain.     

Esterase XIX. Biochemical and ultrahistochemical investigations of the non specific esterase in nuclei from mouse liver.

The present investigations reveal that the non specific esterase from mouse liver nuclei is exclusively located in the perinuclear cistern and that the nuclear chromatin does not contain any esterase as a rule. However, esterase is associated with lipid droplets which are seldomly found within nuclei. Two different esterases are demonstrated with the employed substrates in the nuclear envelope. It is exemplified that the esterase, found in isolated nuclei, can neither be understood as qualitative nor as quantitative equivalent of the esterase demonstrated ultrahistochemically at nuclear membranes.     

Distribution of acid and alkaline deoxyribonucleases in white and grey matter regions of growing and aging chick brain

The activities of acid and alkaline deoxyribonucleases in the white and grey matter areas of growing and old chick cerebrum were measured. Two marker enzymes for glial cells, butyrylcholinesterase and carbonic anhydrase were also measured in these regions. Higher specific activities of both butyrylcholinesterase and carbonic anhydrase were found in the white matter region at all the stages studied. Acid and alkaline deoxyribonuclease activities were observed in both white and grey matter. The decrease in the specific activity of acid deoxyribonuclease with advancement of age was more pronounced as compared to the alkaline deoxyribonuclease Marked reduction in total acid deoxyribonuclease activity in white matter, beyond the age of 130 days, was observed. On the other hand, total alkaline deoxyribonuclease activity in both white and grey matter continued to increase with age Further, the activity per mg of DNA also increased in white matter of the old brain. These results indirectly suggest a continued role for alkaline deoxyribonuclease in glial cells formed at a later age.     

Differential distribution of immunoreactive angiotensinogen in the hind-brain and spinal cord of neonatal and adult rats

The present communication deals with the cytochemical localization of angiotensinogen (ATG) immunoactivity in the hind-brain and spinal cord of neonatal (1-day-old) and adult (3-month-old pregnant) female rats. In the neonatal hind-brain, the immunoreactive cells were more numerous than in that of adult rats. In the adult rat hind-brain, the number of ATG-positive cells was quite limited in each nucleus. Further, in some nuclei, only neurons or neuroglia were positive, while in others the immunoactivity was observed in both the components. Spinal cords of neonatal rats showed a few undifferentiated ATG-positive cells in the grey matter. Contrary to this, the spinal cord of adult animals contained numerous immunoreactive glial cells in the grey matter, fasciculus cuneatus and fasciculus gracilis. Immunoactivity in the neurons was localized in the Nissl bodies.     

The Self-Liking Brain: A VBM Study on the Structural Substrate of Self-Esteem

Abundant evidence suggests that self-esteem is an important personality resource for emotion regulation in response to stressful experiences. It was thus hypothesized that the relative grey matter volume of brain regions involved in responding to and coping with stress is related to individual differences in trait self-esteem. Using structural magnetic resonance imaging of 48 healthy adults in conjunction with voxel-based morphometry and diffeomorphic anatomical registration using exponentiated lie algebra (VBM-DARTEL), positive associations between self-esteem and regional grey matter volume were indeed found in the anterior cingulate cortex (ACC), right lateral prefrontal cortex (LPFC), right hippocampus, and left hypothalamus. In addition, self-esteem positively covaried with grey matter volume in the right temporo-parietal junction (TPJ), which has been implicated in pride and theory of mind. The results suggest that persons with low self-esteem have reduced grey matter volume in brain regions that contribute to emotion/stress regulation, pride, and theory of mind. The findings provide novel neuroanatomical evidence for the view that self-esteem constitutes a vital coping resource.     

Early manifestations and mechanism of the neurotoxic action of organophosphorus pesticides

The inhibition of neurotoxic esterase activity in chicken brain has been studied in vitro and in vivo. Aphos exposure, causing chicken paralysis, has demonstrated that the initial stage of delayed neurotoxicity was significant esterase activity inhibition (by 60-80%) within 3-24 hours after the pesticide administration. The inhibition of cholinesterase activity occurred both in the blood and sciatic nerve. The delayed conduction through peripheral nerves caused by demyelination has been revealed in the latent period (before the clinical signs of intoxication).