Effects of the removal of olfactory bulbs on the appearance and then on the latency of the "mouse-killing reaction" in the rat of the Wistar SM strain

The 20% of male 5-6 month-old Wistar rats SM prove to be natural killers. A four-month long insulation of "surely non-killer" rats has not allowed to notice a mouse-killing behaviour in any animal. The total bilateral removal of olfactory bulbs in "non-killer rats" causes a "mouse-killing behaviour" in all the animal 24 hours after the operation, but with a latency of response that has proved different in the various rats. Precisely, while 24 hours and 15 days after the bulb operation the rats can be distinguished into "rapid killers" and "slow killers", after 30 days all the animals become "rapid killers" with a remarkably shortened period of mouse-killing latency (1 - 60 seconds).     

Identification of the LH and TSH-secreting cells in the pituitary gland of the rhesus monkey

Summary Pituitary glands from juvenile (pre-pubertal) and adult male and female rhesus monkeys were examined following immunocytochemical staining with antisera to the beta subunits of ovine luteinizing hormone (LH) and of human thyroid stimulating hormone (TSH). The LH antiserum reacts with a cell that is PAS-positive, occurs singly and is randomly distributed throughout the pars distalis. The diameter of these cells is approximately 11.5 m. They do not seem to vary in number in either juveniles (pre-pubertals) or adults, or in males or females. There appears to be fewer LH cells in the pituitary glands of pregnant and lactating females. In addition to staining cells in the pars distalis, the antiserum also reacts with a population of cells located in the pars tuberalis.The cells that stain with the anti-TSH serum are confined primarily to the pars distalis. They are approximately 15.8 m in diameter and are generally found in groups or clusters located in the anterior and medial regions of the gland. The TSH cells vary in number from one animal to another; however, this variability is unrelated to the age or the sex of the animals. No demonstrable changes occur in the number of TSH cells during pregnancy or lactation.Supported by NIH General Research Support Grant RR05654The author wishes to express appreciation to the Hormone Distribution Program of NIAMDD for the preparations of ovine FSH, TSH and human TSH, and to Drs. H. Papkoff for the ovine LH and LH, L. Reichert for the human FSH, J. Vaitukaitis for the anti-human TSH, and L.A. Sternberger for the PAP complex     

Differing immunoreactivities of somatostatin in the cortex and the hypothalamus of the rat

Summary Using an antibody against somatostatin (antiserum F), two somatostatin-immunoreactive systems, (i) a hypothalamic and (ii) an extrahypothalamic cortical system, are demonstrated in the rat. Another antiserum raised against somatostatin (antiserum BS 102) stains only the axons but not the perikarya of the hypothalamic system; the cortical somatostatin system does not react with this antiserum. The electron microscopic findings do not allow decision whether the above-mentioned hypothalamic and cortical neurons possess a common prohormonal form of somatostatin, immunoreactive only with antiserum F. They show, however, that the granules in both neuronal systems differ considerably; in the cortical neurons they measure approximately 65 nm in diameter, in the hypothalamic neurons 90–120 nm in diameter. Thus, both somatostatin systems are different and independent from one another.Supported by the Deutsche Forschungsgemeinschaft (Grant Nr. Kr 569/3) and the Stiftung Volkswagenwerk     

On the sufficiency of the velocity field for perception of heading

All models of self-motion from optical flow assume the instantaneous velocity field as input. We tested this assumption for human observers using random-dot displays that simulated translational and circular paths of movement by manipulating the lifetime and displacement of individual dots. For translational movement, observers were equally accurate in judging direction of heading from a velocity field with a two-frame dot life and a direction field in which the magnitudes of displacement were randomized while the radial pattern of directions was preserved, but at chance with a speed field in which the directions were randomized, preserving only magnitude. Accuracy declined with increasing noise in vector directions, but remained below 2.6° with a 90° noise envelope. Thus, the visual system uses the radial morphology of vector directions to determine translational heading and can tolerate large amounts of noise in this pattern. For circular movement, observers were equally accurate with a 2-frame velocity field, 3-frame acceleration displays, and 2-frame and 3-frame direction fields, consistent with the use of the pattern of vector directions to locate the center of rotation. The results indicate that successive independent velocity fields are sufficient for perception of translational and circular heading.     

The return of the Red Queen, or the law of the growth in the mean duration of the existence of genera during evolution

Phanerozoic marine genera apparently do not become less extinction-prone with age. Higher extinction probability in "young" cohorts of genera is better explained by initially different levels of extinction-tolerance of genera in the cohort. This fact agrees with one of the two basic statements of the "Red Queen" hypothesis (Van Valen, 1973). In the second statement (the idea that the increase in fitness lowers extinction probability) the term "fitness" should be changed to "adaptability". The increase of extinction-tolerance, that can be interpreted as the increase of adaptability to unpredictable changes of environment, is found in succession of "generations" of genera that replace one another through time. This increase reveals itself, firstly, in the growth of mean duration of genera, as well as in the decrease of extinction/origination rates, gradual accumulation of long-lived genera and origination of genera with higher duration. The increase of adaptability may be caused by selective extinction of stenotopic, ecologically specialized forms; Cope's law; evolution of ecosystems that involves development of more effective mechanisms of sustaining homeostasis which may stimulate the recovery of a genus after partial extinction.     

Cytochemical evidence for the presence of actin in the nucleus of the voodoo lily appendix

Immunoflorescence microscopy of sections of the voodoo lily Sauromatum guttatum appendix stained with monoclonal antibodies against -smooth muscle actin and cytoplasmic actin revealed different staining intensity of different parts of the cell. The anti-cytoplasmic-actin recognized antigens present mainly in the cytoplasm, and the anti--smooth muscle-actin recognized more intensively antigens present in the nuclei. A positive staining of the nucleus was also obtained with FITC–phalloidin confirming the presence of actin in its filamenous form in the nucleus. The presence of a nuclear -smooth muscle-actin-like protein was further confirmed by confocal laser microscopy. On Western blots, the two anti-actins labelled a protein band that comigrated with standard actin at the approximate molecular weight of 43kDa. Several other proteins interacted with the two antibodies to a different degree. The monoclonal antibodies against -tubulin subunit stained only the periphery of the cytoplasm and anti-pan cytoplasmic myosin stained the cytoplasm weakly. On a Western blot, anti--tubulin subunit primarily recognized a protein band at the appropriate molecular weight of 50kDa. This is the first cytochemical evidence for the presence of -smooth muscle-actin-like protein in the plant nucleus.     

On the computational architecture of the neocortex

This paper is a sequel to an earlier paper which proposed an active role for the thalamus, integrating multiple hypotheses formed in the cortex via the thalamo-cortical loop. In this paper, I put forward a hypothesis on the role of the reciprocal, topographic pathways between two cortical areas, one often a higher area dealing with more abstract information about the world, the other lower, dealing with more concrete data. The higher area attempts to fit its abstractions to the data it receives from lower areas by sending back to them from its deep pyramidal cells a template reconstruction best fitting the lower level view. The lower area attempts to reconcile the reconstruction of its view that it receives from higher areas with what it knows, sending back from its superficial pyramidal cells the features in its data which are not predicted by the higher area. The whole calculation is done with all areas working simultaneously, but with order imposed by synchronous activity in the various top-down, bottom-up loops. Evidence for this theory is reviewed and experimental tests are proposed. A third part of this paper will deal with extensions of these ideas to the frontal lobe.     

Spermatogonia and the cycle of the seminiferous epithelium in the nine-banded armadillo

Summary The cycle of the seminiferous epithelium of the nine-banded armadillo can be divided into ten stages. As in most mammals, only one stage is observed per tubular cross-section. The process of spermiogenesis can be divided into thirteen steps according to the development of the acrosomal system and the flagellum. Four generations of spermatogonia are observed in the germinal epithelium: 1) stem cells, 2) type A, 3) intermediate, and 4) type B spermatogonia. The stem cell is characterized by a highly irregular nucleus and the presence of glycogen in its cytoplasm. The type A spermatogonium contains an oblong nucleus with one or two shallow infoldings of the nuclear membrane. The intermediate spermatogonium contains an ovoid nucleus characterized by one or two nuclei and heterochromatin scattered in the nucleoplasm. The nucleus of the type B spermatogonium is more spherically shaped with a centrally placed nucleolus and heterochromatin associated with the nuclear envelope.The author wishes to acknowledge the technical assistance of Teri Lane     

The ultrastructure of the corpus luteum of the guinea-pig

Summary An electron-microscopic investigation, based on the suggestion that differences seen in progesterone levels under differing hormonal conditions might be reflected in the ultrastructural organisation of the lutein cells of the guinea-pig was undertaken. Comparisons were made between corpora lutea taken from animals during the normal oestrous cycle, pregnancy and lactation, and after hysterectomy or hypophysectomy.The lutein cells from the oestrous cycle corpus luteum appeared to be of two types, light and dark. The former were more numerous. The main difference between them lay in the arrangement of the endoplasmic reticulum. Lutein cells from corpora lutea (with the exception of the old degenerating corpora lutea) all contained well-developed agranular endoplasmic reticulum, little granular endoplasmic reticulum, several electron-dense lipid granules, lysosomal bodies which ranged from small spherical bodies to large autophagic vesicles and mitochondria. The mitochondria were numerous, and in the corpus luteum of pregnancy, they were closely associated with the parallel arrays of granular endoplasmic reticulum.With minor exceptions, the lutein cells of the guinea-pig present a strikingly uniform picture despite their hormonal condition.The manner in which this uniformity of ultrastructure may be related to observed differences in progesterone levels in the corpus luteum of the guinea-pig is discussed.Meat and Livestock Commission (MLC) Scholar.The authors wish to thank Dr. J. S. Perry for doing the surgery involved in this work and for the specimens of corpora lutea of hysterectomy. They are also grateful to him for his helpful discussions and interest throughout.     

Identification of the novel localization of tenascinX in the monkey choroid plexus and comparison with the mouse

Tenascin-X (Tn-X) belongs to the tenascin family of glycoproteins and has been reported to be significantly associated with schizophrenia in a single nucleotide polymorphism analysis in humans. This finding indicates an important role of Tn-X in the central nervous system (CNS). However, details of Tn-X localization are not clear in the primate CNS. Using immunohistochemical techniques, we found novel localizations of Tn-X in the interstitial connective tissue and around blood vessels in the choroid plexus (CP) in macaque monkeys. To verify the reliability of Tn-X localization, we compared the Tn-X localization with the tenascin-C (Tn-C) localization in corresponding regions using neighbouring sections. Localization of Tn-C was not observed in CP. This result indicated consistently restricted localization of Tn-X in CP. Comparative investigations using mouse tissues showed equivalent results. Our observations provide possible insight into specific roles of Tn-X in CP for mammalian CNS function.Key words: tenascin-X, choroid plexus, monkey, mouse, Ehlers-Danlos syndrome, schizophrenia.The tenascins (Tn) are a family of four glyco-protein members – tenascin-C (Tn-C), tenascin-R (Tn-R), tenascin-W (Tn-W) and tenascin-X (Tn-X) – found diversely in the extra-cellular matrix of vertebrate organs (Hsia and Schwarzbauer, 2005; Tucker and Chiquet-Ehrismann, 2009). Important functions of Tn have been investigated in developmental cell adhesion modulation and pathological conditions such as wound healing and tumourigenesis (Adams and Watt, 1993; Hsia and Schwarzbauer, 2005; Tucker and Chiquet-Ehrismann, 2009). Tn-C and Tn-R are prominent in the nervous system and play a role in the development of neurite outgrowth and postnatal synaptic plasticity (Yamaguchi, 2000; Chiquet-Ehrismann and Tucker, 2004; Dityatev and Schachner, 2006). Tn-W is found abundantly in the developing bone and stroma of certain tumours (Chiquet-Ehrismann and Tucker, 2004; Tucker and Chiquet-Ehrismann, 2009). Tn-X is the first tenascin member shown to be clearly associated with the human connective tissue disorder Ehlers–Danlos syndrome (EDS; Burch et al., 1997). Patients with a Tn-X deficiency suffer from skin hyperextensibility, joint hypermobility and poor wound healing ability (Bristow et al., 2005). These symptoms are caused by the occurrence of abnormal irregular collagen fibres. Tn-X plays a role in collagen fibrillogenesis by directly binding to collagen (Mao et al. 2002; Minamitani et al. 2004). Mice with a Tn-X deficiency also showed skin symptoms comparable with those of EDS (Mao et al., 2002).Interestingly, in an analysis of human single nucleotide polymorphisms, Tn-X was reported to be significantly associated with schizophrenia (Wei and Hemmings, 2004; Tochigi et al., 2007). However, thus far, there have been no neuroanatomical reports on the involvement of Tn-X in schizophrenia. In the mammalian central nervous system (CNS), Tn-X mRNA expression has only been shown in the rat meninges of the olfactory bulb (Deckner et al., 2000). Recently, we found novel Tn-X localizations in the adult mouse leptomeninges trabecula in the cerebral cortex and in the connective tissue in the lateral ventricle choroid plexus (CP; Imura and Sato, 2008). Our finding of Tn-X localization in CP, which produces cerebrospinal fluid (CSF), might be a key factor in the investigation of the association between CSF metabolism and enlarged ventricles in schizophrenia. Enlarged ventricles are typical structural abnormalities associated with schizophrenia (Staal et al., 1999). Furthermore, CP secretes biologically active molecules into the CSF for brain development, activity and protection (Strazielle and Ghersi-Egea, 2000; Brown et al., 2004; Thouvenot et al., 2006; Johanson et al., 2008). In these molecules, for instance, there is a brain-derived neurotrophic factor (BDNF), the gene expression level and polymorphism of which have been analysed in relation to the pathogenesis of schizophrenia (Buckley et al., 2007). One study reported that BDNF is able to stimulate Tn-X expression in vitro (Takeda et al., 2005).The validity and limitations of animal models (rodents and monkeys) for use in the study of schizophrenia have been discussed (Tordjman et al., 2007). The authors concluded that monkeys appear to be an interesting social interaction model, more so than rodents, because of their complex well-organized social structure. In addition to differences in social structure, the dopaminergic system of rats and monkeys is quite different (García-Cabezas et al., 2009), and dysfunction of the dopaminergic system is related to schizophrenia (Wang et al. 2008).The CSF outflow system has been studied in some animal models (Kapoor et al., 2008). An anatomical difference in arachnoid granulations has been shown between rodents and monkeys (Krisch, 1988). Arachnoid granulations in monkeys are structurally similar to those in humans (Cooper, 1958; Krisch, 1988). In contrast, arachnoid granulations in rodents are similar to those of cats and dogs (Krisch, 1988). It is possible that Tn-X localization in CP is different between rodents and monkeys.Therefore, details concerning Tn-X localization in monkey CP need to be clarified. In the present study, we compared the immunohistochemistry of Tn-X in monkey CP with that in mouse CP. Subsequently, to verify the reliability of Tn-X localization, we compared it with Tn-C localization in corresponding regions using neighbouring sections.     

Role of the biological activity of serotonin in the production of the "shock lung" syndrome]

The influence of the serotin biological activity on forming the "shock" lung syndrome was revealed in experiments on rats. Tachyhyperpnea with predominance of functional emphysema and a small number of atelectic tissue areas were observed in the animals with traumatic "shock" during the serotonin hypersecretion. Tachyhypopnea with a significant predominance of atelectiv areas was seen during the serotonin hypoproduction.     

Architecture of the media of the arterial vessels in the dog brain: A scanning electron-microscopic study

Summary The architecture of the media of arterial vessels in dog brain was investigated using scanning electron microscopy. The arrangement and shape of the circularly-oriented smooth muscle cells varied with vessel diameter: The arteries (>100 m in diameter) had 4–10 layers of spindle-shaped smooth muscle cells; the muscular arterioles (30–100 m), 2–3 layers of spindle-shaped smooth muscle cells; the terminal arterioles (10–30 m), a compact layer of spindle-shaped smooth muscle cells with more dominant nodular or rod-like processes and thin lateral processes; and the precapillary arterioles (5–15 m), a less compact layer of branched smooth muscle cells.Longitudinally-oriented muscles were observed in the medio-adventitial border. The distribution and arrangement of these muscles varied with vessel size: in the large arteries (> 300 m in diameter), at the branching sites only; in the small arteries (100–300 m), at both the branching and non-branching sites; in the muscular arterioles, at both the branching and non-branching sites in a reticular arrangement with some muscle cells having an asteroid appearance; in the terminal aterioles, only asteroid-like muscle cells were found at the branching and non-branching sites.     

Characteristics of cells derived from the girdle region of the pre-implantation blastocyst of the donkey

Summary The establishment of a monolayer culture of cells derived from the girdle region of a 34-day-old donkey conceptus is described. These cells have had over 100 repeated passages in culture. Low levels of pregnant mares' serum gonadotrophin (PMSG, eCG) could be detected in the cells by indirect immunofluorescence using some monoclonal anti-eCG antibodies, but the cells did not secrete eCG as measured by radioimmunoassay or inhibition of haemagglutination. There was marked nuclear polymorphism with binucleate and occasional multinucleate cells. The cells were strongly reactive with wheatgerm agglutinin and concanavalin A suggesting the synthesis of many glycosylated products. Some cells were reactive with antisera to prekeratin, others with antisera to vimentin. The cells also contained actin (showing peculiar intercellular communications), -actinin and tubulin. They were able to metabolize certain steroid precursors, but there was no definitive evidence for the presence of aromatase or ⁵-3-hydroxysteroid dehydrogenase in these cells. This cell line appears to resemble trophectodermal girdle epithelium at a stage of development prior to the onset of eCG production, and may be useful in studies on the control of expression of this substance.Dr. S. Kellie is now at the Imperial Cancer Research Fund Laboratories, Lincoln Inn's Fields, London     

Ultrastructure of the surface of the iris in the rat eye

Summary The surface structure of the iris in the rat eye was studied by light and electron microscopy.The anterior surface of the rat iris is covered with a discontinuous layer of large, polygonal endothelial cells with microvilli on their surface. Crypts and holes between adjacent endothelial cells extend into the stroma and form there a complicated network of interconnected spaces occupying about one half or more of the volume of the pupillary part of the stroma. The crypts are occasionally partly covered with endothelial cells. The posterior surface is covered with a continuous layer of polyhedronal epithelial cells. These are covered with many folds and processes, partly masked by an amorphous coat. The sphincter pupillae and dilatator muscles are possible to recognize on the scanning electron micrographs as well as blood vessels and nerve fibers in the iris stroma.The endothelial cells show many structural similarities with the endothelial cells on the cornea, probably reflecting their common origin. The results obtained, especially those from the scanning electron microscopic studies, are discussed and interpreted in relation to previous studies. The advantages in using different light and electron microscopic techniques are stressed.Supported by grants from Magnus Bergwall's Stiftelse and the Swedish Medical Research Council (B71-12X-2543-03).     

Ultrastructure of the tubule of the aglomerular teleost Nerophis ophidion

Summary The tubules in the aglomerular kidney of Nerophis ophidion are composed of cells showing different types of specializations of their plasma membrane. All cells possess a luminal brush border composed of microvilli, and show presence of vesicles with 100 Å thick unit membranes — some containing electron dense material —, tubular elements, multivesicular bodies, and plasma membrane invaginations in their apical cytoplasm. These features suggest an absorptive function of the cells. The apical portions of the cells are supplied with typical cilia.Some cells have abundant basilar plasma membrane invaginations usually lacking cytoplasmic organelles. Other cells appear to form interdigitating basilar cytoplasmic processes containing mitochondria; still other cells have smooth basilar cell membranes. These findings are discussed with reference to the known secretory function of the tubules and are compared with tubular fine structure in other species. It was concluded that urine formation by tubular secretion may occur in cells with different types of basilar cell membrane specializations.The occurrence of coated vesicles associated with invaginated basilar plasma membranes indicates transport of proteins (from peritubular blood vessels ?) at these sites.The tubule cells have abundant smooth surfaced endoplasmic reticulum and large and numerous active Golgi zones.Supported by grants from Fonden til Videnskabens Fremme and Therese och Johan Anderssons Minne. Part of this study was done at the Zoologica Stazione, Naples.The assistance of Miss Britt-Marie Petterson and Mr. Magnus Norman is gratefully acknowledged.     

Evaluation of the system for controlling the quality of the HBsAg detection in the system of screening laboratories

The two-stage control system, ensuring the high quality of serological investigations in the network of screening laboratories in Moscow was developed and introduced into practice. At the first stage the entry control of the quality of the test system for the detection of HbsAg, coming to the screening laboratories, is made in the reference laboratory with the use of specially developed "representative" panels, as well as the test systems for comparison ("reference" test systems). Then "minipanels" are formed from specimens included into the "representative" panels, which are used for the evaluation of the quality of laboratory investigations made in the screening laboratories. The high quality of such system for controlling the quality of the detection of HBsAg in the screening laboratories of Moscow is shown.     

Reflection of the Intelligence Structure in the Spatiotemporal Features of the Baseline EEG

The EEG correlates of the verbal, numerical, and figural IQ components according to the power and coherence characteristics of the baseline EEG in six frequency bands were studied taking into account personality traits of subjects (extroversion, neuroticism, psychoticism, and anxiety). Analysis of variance and correlation showed that a decreased power of the low-frequency _{1, 2}and ₁ rhythms and increased EEG power in the ₂ band with the right-hemispheric dominance were characteristic of persons with higher intelligence. These EEG characteristics were associated with increased interhemispheric interaction according to the coherence indices and increased coherence within the right hemisphere. Each of the intelligence components (verbal, numerical, and figural) was characterized by a specific baseline frequency–spatial EEG pattern distinguished by specific interactions, predominantly, between the frontal and caudal cortical regions in the and/or ₂ frequency bands.     

State of the contractile apparatus during the development of a pathological process in the muscles. III. The nature and sequence of the structural changes in the contractile apparatus in Zenker's necrosis]

Using polarized ultraviolet (UV) fluorescence microscopy, it was shown that the local damage of muscle fibres causes in their morphologically unchanged parts the alternation of regions, being in different functional states referred to as "pseudocontraction" and "superrelaxation". The pattern of UV fluorescence anisotropy suggests that conformation of contractile proteins by "pseudocontraction" is similar to that at contraction, though changes in sarcomere length do not occur. The "superrelaxation" is characterized by a desorganization of myofilaments. During the spreading of Zenker's necrosis, the "pseudocontraction" is seen transferred first into "superrelaxation", and then into irreversible contracture and rigor. "The boundary of Zenker's necrosis" overlaps with the boundary of the self-propagating irreversible contracture. There is no proper boundary of Zenker's necrosis, because the destructive changes are observed over all the muscle fibre. Contraction nodules arise in the regions of "superrelaxation" and follow the changes of the contractile system, peculiar of contracture. The study of the influence of medium ionic composition on the development of Zenker's necrosis suggests that the arising and spreading of destruction are inseparably associated with the irreverrsible changes of intracellular membrane structures, and with the possibility of propogation of the damage signal by these structures along muscle fibres.     

On the nature of the ''nothing dehydrogenase'' reaction

Summary The biochemical mechanism underlying the nothing dehydrogenase reaction during the histochemical demonstration of dehydrogenases using tetranitro BT as the final electron acceptor has been investigated in unfixed, frozen rat liver sections. The reaction is stronger with NAD⁺ than either with NADP⁺ or in the absence of coenzyme. As much as 50% of the reaction is due to lactate dehydrogenase converting endogenous lactate and is largely inhibited by pyruvate. No NAD⁺-dependent alcohol dehydrogenase activity was detected at pH 7.45, the pH used for the incubations. The coenzyme-independent activity may be caused by SH-groups present in proteins and compounds like glutathione and cysteine and can be inhibited byN-ethylmaleimide andp-chloromercuribenzoic acid. It was also found that the nothing dehydrogenase reaction mainly occurs during the first few minutes of incubation, levelling off quickly to a slow rate. When studying the kinetics of dehydrogenase reactions with tetrazolium salts, it should be realized that the nothing dehydrogenase reaction, which as a whole is nonlinear with time, can interfere seriously with the dehydrogenase reaction to be analysed and may yield initial reaction rates that are too high. The findings of the present study reveal the nature of the reactions used for detection of necrosis in tissues with tetrazolium salts.