Signaling in the Chemosensory Systems

The mammalian olfactory system is not uniformly organized but consists of several subsystems each of which probably serves distinct functions. Not only are the two major nasal chemosensory systems, the vomeronasal organ and the main olfactory epithelium, structurally and functionally separate entities, but the latter is further subcompartimentalized into overlapping expression zones and projection-related subzones. Moreover, the populations of ‘OR37’ neurons not only express a unique type of olfactory receptors but also are segregated in a cluster-like manner and generally project to only one receptor-specific glomerulus. The septal organ is an island of sensory epithelium on the nasal septum positioned at the nasoplatine duct; it is considered as a ‘mini-nose’ with dual function. A specific chemosensory function of the most recently discovered subsystem, the so-called Grueneberg ganglion, is based on the expression of olfactory marker protein and the axonal projections to defined glomeruli within the olfactory bulb. This complexity of distinct olfactory subsystems may be one of the features determining the enormous chemosensory capacity of the sense of smell.     

PCR of DNA from dried blood spots on filter paper coupled to a simple DNA enzyme immunoassay for rapid detection of HIV-1

Conclusions The application of PCR and techniques confirming the specificity of PCR products in routine diagnostic laboratories, requires that the procedures are simple and reproducible. The microtitre plate assay we described for detection of HIV-1 is sensitive, simple, rapid and reproducible. The DEIA test is perfectly compatible with standard enzyme linked immunosorbent assay equipment, permitting the processing of a large number of samples. Moreover, the ability to analyze DNA extracted from dried blood specimens, as demonstrated in this study, allows the long-term storage of blood samples even at elevated temperatures and after transport over long distances.     

The cyclic nucleotide-gated ion channel CNGA3 contributes to coolness-induced responses of Grueneberg ganglion neurons

Localized to the vestibule of the nasal cavity, neurons of the Grueneberg ganglion (GG) respond to cool ambient temperatures. The molecular mechanisms underlying this thermal response are still elusive. Recently, it has been suggested that cool temperatures may activate a cyclic guanosine monophosphate (cGMP) pathway in the GG, which would be reminiscent of thermosensory neurons in Caenorhabditis elegans. In search for other elements of such a cascade, we have found that the cyclic nucleotide-gated ion channel CNGA3 was strongly expressed in the GG and that expression of CNGA3 was confined to those cells that are responsive to coolness. Further experiments revealed that the response of GG neurons to cool temperatures was significantly reduced in CNGA3-deficient mice compared to wild-type conspecifics. The observation that a cGMP-activated non-selective cation channel significantly contributes to the coolness-evoked response in GG neurons strongly suggests that a cGMP cascade is part of the transduction process.     

Continuous registration of X,Y-coordinates and angular position in behavioural experiments

Summary An electronic camera and 2 simple additional circuits for the registration of the X, Y-coordinates or the angular position of animals in behavioural experiments are described.     

Acquisition of specific cytotoxic activity by human T4+ T lymphocytes in culture

Mature human T lymphocytes can be separated by monoclonal antibodies OKT4 and OKT8 according to their surface phenotypes into T4+T8- and T4-T8+ subsets. From short-term experiments using bulk cultures, the helper/inducer function has been assigned to the T4+T8- subset and the cytotoxic/suppressor function to the T4-T8+ subset. Thus if T lymphocytes are separated after stimulation in a mixed lymphocyte reaction (MLR), the entire cytotoxic activity is found in the T4-T8+ fraction whereas the T4+T8- fraction shows no detectable cytotoxicity. If, however, T lymphocytes are cloned after MLR and grown in long-term culture, a surprisingly large fraction of T4+ T lymphocyte clones (TLC) shows cytotoxic activity. Here we report that T4+ TLC can acquire specific cytotoxicity during in vitro cultivation.     

Metal Complexes:Novel Chiral Dopants with High Helical Twisting Power in Liquid Crystals

1 Introduction A particularly efficient and elegant route to chiral mesophases is based on the addition of small amounts of an enantiomerically pure dopant to a nematic phase so that the latter is converted into a cholesteric phase(See Fig.1).Fig.1 A nematic phase is converted into a cholesteric phase Fig.2 Bis-chelated imine-alkoxy-titanium complexes2 ExperimetalBis-chelated imine-alkoxy-titanium complexes like 1 and 2 (Fig.2) have been synthesizedstarting from triphenyl-substituted aminoethanols, T...     

Observation of two-dimensional discrete solitons in optically induced nonlinear photonic lattices

Nonlinear periodic lattices occur in a large variety of systems, such as biological molecules, nonlinear optical waveguides, solid-state systems and Bose-Einstein condensates. The underlying dynamics in these systems is dominated by the interplay between tunnelling between adjacent potential wells and nonlinearity. A balance between these two effects can result in a self-localized state: a lattice or 'discrete' soliton. Direct observation of lattice solitons has so far been limited to one-dimensional systems, namely in arrays of nonlinear optical waveguides. However, many fundamental features are expected to occur in higher dimensions, such as vortex lattice solitons, bright lattice solitons that carry angular momentum, and three-dimensional collisions between lattice solitons. Here, we report the experimental observation of two-dimensional (2D) lattice solitons. We use optical induction, the interference of two or more plane waves in a photosensitive material, to create a 2D photonic lattice in which the solitons form. Our results pave the way for the realization of a variety of nonlinear localization phenomena in photonic lattices and crystals. Finally, our observation directly relates to the proposed lattice solitons in Bose-Einstein condensates, which can be observed in optically induced periodic potentials.     

Oestrogen protects FKBP12.6 null mice from cardiac hypertrophy

FK506 binding proteins 12 and 12.6 (FKBP12 and FKBP12.6) are intracellular receptors for the immunosuppressant drug FK506 (ref. 1). The skeletal muscle ryanodine receptor (RyR1) is isolated as a hetero-oligomer with FKBP12 (ref. 2), whereas the cardiac ryanodine receptor (RyR2) more selectively associates with FKBP12.6 (refs 3, 4, 5). FKBP12 modulates Ca2+ release from the sarcoplasmic reticulum in skeletal muscle and developmental cardiac defects have been reported in FKBP12-deficient mice, but the role of FKBP12.6 in cardiac excitation-contraction coupling remains unclear. Here we show that disruption of the FKBP12.6 gene in mice results in cardiac hypertrophy in male mice, but not in females. Female hearts are normal, despite the fact that male and female knockout mice display similar dysregulation of Ca2+ release, seen as increases in the amplitude and duration of Ca2+ sparks and calcium-induced calcium release gain. Female FKBP12.6-null mice treated with tamoxifen, an oestrogen receptor antagonist, develop cardiac hypertrophy similar to that of male mice. We conclude that FKBP12.6 modulates cardiac excitation-contraction coupling and that oestrogen plays a protective role in the hypertrophic response of the heart to Ca2+ dysregulation.