CB1 receptors in the thalamic reticular nucleus during acute immobilization stress of the rat : an immunohistochemical study

Cannabinoids and opioids interact in a number of ways that could be therapeutically beneficial. The CB1 receptors are implicated with the endocannabinoid-mediated modulation of stress, pain, visceral sensation, synaptic plasticity in the thalamus via GABAergic signaling. Thalamic reticular nucleus (TRN) is a thin sheet of GABAergic neurons surrounding anterolateral surface of the thalamus. In our immunohistochemical study we demonstrated expression of CB1 immunoreactive neurons in a light microscope during a normal condition and after the acute stress in the rats. We found higher expression of CB 1 immunoreactivity in stressed animals compared with control group.Opioids and cannabinoids have been shown to have analgesic properties and they are considered as drug targets for the treatment of numerous neurological disorders, pain and stress

Immunohistochemical study on distribution of cannabinoid cb1 receptors in the rat`s prefrontal cortex after cold stress procedure

The prefrontal cortex (PFC), which mediates the emotional coping response to different stressful paradigms, is composed of distinct parts depends on stimulus involved physical or psychological stress. It also plays a role in a number of neurological conditions. It`s known that neuroendocrine control of homeostatic and reproductive functions including stress response and energy metabolism is fulfils by important signaling molecules as endogenous cannabinoids. The aim of the present study was to examine the effects of cold stress on distribution of CB1- receptors in PFC of rats. Immunohistochemical procedure for CB1-receptors was performed in adult male Wistar rats. The data were entered in the computer program, recorded automatically, calculated and compared by Student`s t-test. We found CB1-immunoreaction in axons and dendrites as well as in cell bodies where they presented as puncta on somata. The cells bodies were comprised of several distinct shapes: pyramidal, oval, fusiform and multipolar. Numerous fine-beaded fibers and puncta were seen on a handful of pyramidal large-sized neurons and many puncta were observed around the oval-shaped small- and medium-sized neurons.The PFC in cold stress rats demonstrated around 18% higher density of CB1-receptors compared with controls. In conclusion our results showed that cold stress exposure increased distribution of CB1-receptors in PFC of rats. These experimental data suggest that endocannabinoid system in this brain area may play an important role in the continuity of homeostasis in cold stress

Light microscopic immunocytochemical identification of leucine enkephalin

Leucine-enkephalin is a potent and naturally-occurring opioid peptide which serves to inhibit other neurotransmitters involved with pain perception, thereby reducing its emotional and physical impact. Nevertheless, there is little data in the literature concerning leucine-enkephalin-immunoreactivity (Leu-enk-ir) in the human claustrum. The objectives of this study were to confirm the existence of leucine-enkephalin immunoreactive neurons and fibers in the human claustrum. Light microscopy was used to describe their morphology and distribution. Samples of claustrum were obtained from the brains of two females (39 and 48 years of age) and two males (27 and 42 years of age). The brains did not show any overt signs of pathology or trauma. Immunoreactivity to Leuenk was assessed via the Avidin-Biotin Complex Method. Light-microscopic analysis confirmed the presence of Leu-enk-ir neurons and fibres in all areas of the human claustrum. The cell bodies varied in shape and size, and were divided into three groups: small, medium and large. The density of immunostaining varied both within and between the cell types, with some neurons, staining more darkly or lightly than others. The large and medium sized cells most likely correspond to claustrocortical projection neurons while the small-sized cells appear to be inhibitory interneurons. It is our hope that these results will be contributed to a better understanding the functions of claustrum, in both health and disease, given its relationship with the development of autism, schizophrenia, Alzheimer disease, Parkinson disease and Huntington disease

Effect of 5% fluoride varnish application on caries among school children in rural Brazil: a randomized controlled trial

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91213/1/cdoe656.pd

A Geometric Unification of Dualities

We study the dynamics of a large class of N=1 quiver theories, geometrically realized by type IIB D-brane probes wrapping cycles of local Calabi-Yau threefolds. These include N=2 (affine) A-D-E quiver theories deformed by superpotential terms, as well as chiral N=1 quiver theories obtained in the presence of vanishing 4-cycles inside a Calabi-Yau. We consider the various possible geometric transitions of the 3-fold and show that they correspond to Seiberg-like dualities (represented by Weyl reflections in the A-D-E case or `mutations' of bundles in the case of vanishing 4-cycles) or large N dualities involving gaugino condensates (generalized conifold transitions). Also duality cascades are naturally realized in these classes of theories, and are related to the affine Weyl group symmetry in the A-D-E case.Comment: 94 pages, 18 figures. Added referenc

The End of the Rainbow: What Can We Say About the Extragalactic Sub-Megahertz Radio Sky?

The Galactic disc is opaque to radio waves from extragalactic sources with frequencies nu less than ~3 MHz. However, radio waves with kHz, Hz, and even lower frequencies may propagate through the intergalactic medium (IGM). I argue that the presence of these waves can be inferred by using the Universe as our detector. I discuss possible sub-MHz sources and set new non-trivial upper limits on the energy density of sub-MHz radio waves in galaxy clusters and the average cosmic background. Limits based on five effects are considered: (1) changes in the expansion of the Universe from the radiation energy density (2) heating of the IGM by free-free absorption; (3) radiation pressure squeezing of IGM clouds by external radio waves; (4) synchrotron heating of electrons in clusters; and (5) Inverse Compton upscattering of sub-MHz radio photons. Any sub-MHz background must have an energy density much smaller than the CMB at frequencies below 1 MHz. The free-free absorption bounds from the Lyman-alpha forest are potentially the strongest, but are highly dependent on the properties of sub-MHz radio scattering in the IGM. I estimate an upper limit of 6 * 10^4 L_sun Mpc^-3 for the emissivity within Lyman-alpha forest clouds in the frequency range 5 - 200 Hz. The sub-MHz energy density in the Coma cluster is constrained to be less than ~10^-15 erg cm^-3. At present, none of the limits is strong enough to rule out a maximal T_b = 10^12 K sub-MHz synchrotron background, but other sources may be constrained with a better knowledge of sub-MHz radio propagation in the IGM.Comment: Accepted by MNRAS, 4 figures, 20 pages

N=1 and N=2 Super Yang-Mills theories from wrapped branes

We consider supergravity solutions of D5 branes wrapped on supersymmetric 2-cycles and use them to discuss relevant features of four-dimensional N=1 and N=2 super Yang-Mills theories with gauge group SU(n). In particular in the N=1 case, using a gravitational dual of the gaugino condensate, we obtain the complete NSVZ beta-function. We also find non-perturbative corrections associated to fractional instantons with charge 2/n. These non-perturbative effects modify the running of the coupling constant which remains finite even at small scales in a way that resembles to the soft confinement scenario of QCD.Comment: Latex file, 30 pages; several references adde