Although T-type Ca 21 channels are implicated in nociception, the function of specific subtypes has not been well defined. Here, we compared pain susceptibility in mice lacking Ca V 3. to be important in pain perception, the understanding of their function is still at an early stage. Three subtypes of T-type channel have been cloned, namely, Ca V 3.1 (a 1G ), Ca V 3.2 (a 1H ) and Ca V 3.3 (a 1I ) (Cribbs et al. 1998(Cribbs et al. , 2000Gomora et al. 2002;Lee et al. 1999;Zhuang et al. 2000). Gene expression analysis demonstrated that the Ca V 3.2 subtype is predominantly found at sites essential for pain transmission, such as medium-and small-sized sensory neurons of the DRG and the superficial laminae of the dorsal horn (Talley et al. 1999). This expression pattern for Ca V 3.2 indicates that this subtype may be important for peripheral pain perception. Although Bourinet et al. recently showed reduced mechanical nociception in healthy or mononeuropathic rats following antisense-mediated knockdown of Ca V 3.2 , further exploration of the role of this channel in various pain modalities is still needed to fully validating it as a target for analgesic drug development. In the present study, we therefore investigated the roles of the Ca V 3.2 subtype in the perception of various noxious signals as well as mechanical noxious stimuli. Our results revealed that the Ca V 3.2 subtype of T-type Ca 2þ channels † † Two authors equally contributed to this work. ‡ ‡

Abnormal phospholipid metabolism has been implicated in the pathogenesis of schizophrenia, and it was reported that phospholipase C (PLC) b1 is reduced in specific brain areas of patients with schizophrenia. However, the causal relationship of the PLCb1 gene with behavioral symptoms of schizophrenia remains unclear. To address this issue, we have examined the mutant mice lacking PLCb1 for schizophrenia-related phenotypes by performing various behavioral tests, including general locomotor activity, sensorimotor gating, social behaviors, and learning and memory. Phospholipase C b1 knockout mice showed hyperactivities in an open field. They showed impaired prepulse inhibition of acoustic startle response, which was ameliorated by a systemic administration of an antipsychotic D2-receptor antagonist, haloperidol. In addition, they showed abnormal social behaviors, such as lack of barbering behavior, socially recessive trait and lack of nesting behavior. Furthermore, they showed impaired performance in the delayed-nonmatch-to-sample T-maze test. The present results show that the PLCb1 mutant mice share some of the behavioral abnormalities that have been reported in patients with schizophrenia. Thus, the PLCb1-linked signaling pathways may be involved in the neural system whose function is disrupted in the pathogenesis of schizophrenia.

Novelty stimuli cause various behavioral responses, such as exploration and avoidance, and contextual variables may contribute to the behavioral outputs. Here, we tried to compare the behavioral responses to novel objects of five inbred strains of mice (C57BL/6J, 129/svJae, C3H/ HeJ, BALB/cJ and DBA/2J) by using a modified novel object test where a small light-weight cube wrapped with paper was presented to mice in a home cage without beddings. In response to these objects, the C57BL/6J, 129/svJae and C3H/HeJ mice showed mild exploratory behaviors, such as approaching, sniffing or brief contact. In striking contrast, the BALB/cJ and DBA/2J mice, which have been known to show high avoidance/low exploration in other behavioral paradigms, exhibited play-like secondary reactions toward the objects after initial primary exploratory behaviors. Specifically, DBA/2J mice would move the object around in the cage, holding it with their mouths, and BALB/cJ mice would gnaw the object, eventually stripping off the wrapping paper. Such behaviors decreased when similar objects were presented repeatedly. The present results suggest that active manipulations of novel objects may be a relevant parameter for measuring novelty-induced behaviors in mice and appear to be strongly influenced by genetic factors.

Adhesion and friction studies of microelectromechanical systems/nanoelectromechanical systems materials using a novel microtriboapparatus J. Vac. Sci. Technol. A 21, 1528 (2003 10.1116/1.1560711 Determination of nanostructures and mechanical properties on the surface of molybdenum dithiocarbamate and zinc dialkyl-dithiophosphate tribochemical reacted films using atomic force microscope phase imaging techniqueThe molecular design of surface structures with built-in mechanisms for mechanical energy dissipation under nanomechanical deformation and compression resistance provided superior nanoscale wear stability. We designed robust, well-defined trilayer surface nanostructures chemically grafted to a silicon oxide surface with an effective composite modulus of about 1 GPa. The total thickness was within 20-30 nm and included an 8 nm rubber layer sandwiched between two hard layers. The rubber layer provides an effective mechanism for energy dissipation, facilitated by nonlinear, giant, reversible elastic deformations of the rubber matrix, restoring the initial status due to the presence of an effective nanodomain network and chemical grafting within the rubber matrix.