New Instantons in AdS_4/CFT_3 from D4-Branes Wrapping Some of CP^3

With use of a 6-form field strength of ten-dimensional type IIA supergravity over AdS_4 x CP^3, when S^7/Z_k is considered as a S^1 Hopf fibration on CP^3, we earn a fully localized solution in the bulk of Euclideanized AdS_4. Indeed, this object appears in the external space because of wrapping a D4(M5)-brane over some parts of the respective internal spaces. Interestingly, this supersymmetry breaking SU(4)x U(1)-singlet mode exists in already known spectra when one uses the 8_c gravitino representation of SO(8). To adjust the boundary theory, we should swap the original 8_s and 8_c representations for supercharges and fermions in the Aharony-Bergman-Jafferis-Maldacena model. The procedure could later be interpreted as adding an anti-D4(M5)-brane to the prime N=6 membrane theory resulting in a N=0 antimembrane theory while other symmetries are preserved. Then, according to the well-known state-operator correspondence rules, we find a proper dual operator with the conformal dimension of {\Delta}=3 that matches to the bulk massless pseudoscalar state. After that, by making use of some fitting ansatzs for the used matter fields, we arrive at an exact boundary solution and comment on the other related issues as well.Comment: 21 pages, than the previous v2 edition, typos fixe

Marginal Fluctuations as Instantons on M2/D2-Branes

We introduce some (anti)M/D-branes through turning on the corresponding field strengths of the eleven- and ten-dimensional supergravity theories over AdS_4 x M^(7/6) spaces, where we use S^7/Z_k and CP^3 for the internal spaces. Indeed, when we add M2/D2-branes on the same directions with the near horizon branes of Aharony-Bergman-Jafferis-Maldacena model, all symmetries and supersymmetries are preserved trivially. In the case, we gain a localized object just in the horizon. This normalizable bulk massless scalar mode is a singlet of SO(8) and SU(4)x U(1), and agrees with a marginal boundary operator of the conformal dimension of {\Delta}_+=3. However, after performing a special conformal transformation, we see that the solution is localized in the Euclideanized AdS_4 space and is attributable to the included anti-M2/D2-branes, which are also necessary to ensure that there is no backreaction. The resultant theory now breaks all N=8,6 supersymmetries to N=0 while other symmetries are so preserved. The dual boundary operator then sets up from the skew-whiffing of the representations 8_s and 8_v for the supercharges and scalars respectively, while the fermions remain fixed in 8_c of the original theory. Besides, we also address another alternate bulk to boundary matching procedure through turning on one of the gauge fields of the full U(N)_k x U(N)_-k gauge group in the same lines with the similar situation faced in AdS_5/CFT_4 correspondence. The latter approach covers the difficulty already faced with of the bulk-boundary matching procedure for k=1,2 as well.Comment: 21 pages, main structure unchanged, some discussions and references added mainly in the last section, title changed slightly, some typos fixe

Dual Instantons in Anti-membranes Theory

We introduce two ansatzs for the 3-form potential of Euclidean 11d supergravity on skew-whiffed AdS_4 X S^7 background which results in two scalar modes with m^2=-2 on AdS_4. Being conformally coupled with a quartic interaction it is possible to find the exact solutions of the scalar equation on this background. These modes turn out to be invariant under SU(4) subgroup of SO(8) isometry group, whereas there are no corresponding SU(4) singlet BPS operators of dimensions one or two on the boundary ABJM theory. Noticing the interchange of 8_s and 8_c representations under skew-whiffing in the bulk, we propose the theory of anti-membranes should similarly be obtained from ABJM theory by swapping these representations. In particular, this enables us to identify the dual boundary operators of the two scalar modes. We deform the boundary theory by the dual operators and examine the fermionic field equations and compare the solutions of the deformed theory with those of the bulk.Comment: 14 pages, minor changes, added ref

The similarity of astrocytes number in dentate gyrus and CA3 subfield of rats hippocampus

The dentate gyrus is a part of hippocampal formation that it contains granule cells, which project to the pyramidal cells and interneurons of the CA3 subfield of the hippocampus. Astrocytes play a more active role in neuronal activity, including regulating ion flux currents, energy production, neurotransmitter release and synaptogenesis. Astrocytes are the only cells in the brain that contain the energy molecule glycogen. The close relationship between dentate gyrus and CA3 area can cause the similarity of the number of astrocytes in these areas. In this study 5 male albino wistar rats were used. Rats were housed in large plastic cage in animal house and were maintained under standard conditions, after histological processing, The 7 μm slides of the brains were stained with PTAH staining for showing the astrocytes. This staining is specialized for astrocytes. We showed that the number of astrocytes in different (ant., mid., post) parts of dentate gyrus and CA3 of hippocampus is the same. For example, the anterior parts of two area have the most number of astrocytes and the middle parts of two area have the least number of astrocytes. We concluded that dentate gyrus and CA3 area of hippocampus have the same group of astrocytes. © 2007 Asian Network For Scientific Information

The effect of spatial learning on the number of astrocytes in rat dentate gyrus

In this study, we evaluated the effect of spatial learning on the number of astrocytes in the rat dentate gyrus with Morris water maze. Fifteen male albino Wistar rats were divided into three groups as control, reference memory and working memory groups. Each group was consisted of 5 rats. After spatial learning, the brains were histologically examined; the slides were stained with phosphotungstic acid hematoxylin (PTAH) staining to show the astrocytes. We found significant difference in the number of astrocytes in dentate gyrus between control and reference memory groups, and between control and working memory groups as well. When compared two learning groups there was a significant difference in the number of astrocytes between them, being higher in the working memory group. We concluded that the number of astrocytes increased due to spatial learning and this increase can be affected to the period of learning. Our studies of spatial learning and effect of learning techniques (reference and working memory) showed that the technique that has longer period of learning has more effect on the number of astrocytes