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Negative regulation of exocytosis from secretory cells is accomplished through inhibitory signals from [G.sub.i/o] GPCRs by G[beta][gamma] subunit inhibition of 2 mechanisms: decreased calcium entry and direct interaction of G[beta][gamma] with soluble N- ethylmaleimide-sensitive factor attachment protein (SNAP) receptor (SNARE) plasma membrane fusion machinery. Previously, we disabled the second mechanism with a SNAP25 truncation (SNAP25A3) that decreased G[beta][gamma] affinity for the SNARE complex, leaving exocytotic fusion and modulation of calcium entry intact and removing GPCR-G[beta][gamma] inhibition of SNARE- mediated exocytosis. Here, we report substantial metabolic benefit in mice carrying this mutation. Snap2SA3/A3 mice exhibited enhanced insulin sensitivity and beiging of white fat. Metabolic protection was amplified in Snap2SA3/A3 mice challenged with a high-fat diet. Glucose homeostasis, whole-body insulin action, and insulin-mediated glucose uptake into white adipose tissue were improved along with resistance to diet-induced obesity. Metabolic protection in [Snap25.sup.[DELTA]3/[DELTA]3] mice occurred without compromising the physiological response to fasting or cold. All metabolic phenotypes were reversed at thermoneutrality, suggesting that basal autonomic activity was required. Direct electrode stimulation of sympathetic neuron exocytosis from [Snap25.sup.[DELTA]3/[DELTA]3] inguinal adipose depots resulted in enhanced and prolonged norepinephrine release. Thus, the G[beta][gamma]-SNARE interaction represents a cellular mechanism that deserves further exploration as an additional avenue for combating metabolic disease., Introduction Metabolic diseases, such as diabetes and obesity, have an estimated annual global economic impact in the trillions of (US) dollars (1-5). Therapeutic approaches to lower metabolic risk include augmenting [...]

Research has demonstrated the benefits of father involvement with their children and a link between uninvolved fatherhood and societal problems. Children's Centres (n?=?15) received 6?×?90-minute active play sessions designed to foster 6 aspects of parental engagement. Fathers' engagement and attitudes to child physical activity were measured pre- and post-intervention via questionnaire. Acceptability of the intervention was explored through participant and staff focus groups. Results showed no effect on overall time fathers spent with their child during the week (t (36)?=?0.178, p?=?0.860) and the weekend (t (36)?=?1.166, p?=?0.252). Qualitative results demonstrated the sessions provided opportunities for fathers to spend quality time with their children. Parenting self-efficacy increased across the subscale control, t (36)?=?-2.97, p?=?0.04. Fathers increased awareness of their role in motivating their child to play (z?=?-2.46, p?=?0.01). Further longitudinal research is recommended.

We previously developed an incoherent holography technique for use in lattice light sheet (LLS) microscopes that represents a specialized adaptation of light sheet microscopy. Light sheet instruments resolve 3D information by illuminating the sample at 90° to the imaging plane with a sheet of laser light that excites fluorophores in the sample only in a narrow plane. Imaging this plane and then moving it in the imaging z-axis allows construction of the sample volume. Among these types of instruments, LLS microscopy gives higher z-axis resolution and tissue depth penetration. It has a similar working principle to light sheet fluorescence microscopy but uses a lattice configuration of Bessel beams instead of Gaussian beams. Our incoherent light detection technique replaces the glass tube lens of the original LLS with a dual diffractive lens system to retrieve the axial depth of the sample. Here, we show that the system is applicable to all light sheet instruments. To make a direct comparison in the same emission light path, we can imitate the nature of non-Bessel light sheet systems by altering the mask annuli used to create Bessel beams in the LLS system. We change the diffractive mask annuli from a higher NA anulus to a smaller NA anulus. This generates a Gaussian excitation beam similar to conventional light sheet systems. Using this approach, we propose an incoherent light detection system for light sheet 3D imaging by choosing a variable NA and moving only the light sheet while keeping the sample stage and detection microscope objective stationary. [ABSTRACT FROM AUTHOR]

In presynaptic terminals, membrane-delimited Gi/o-mediated presynaptic inhibition is ubiquitous and acts via Gβc to inhibit Ca2+ entry, or directly at SNARE complexes to inhibit Ca21-dependent synaptotagmin-SNARE complex interactions. At CA1-subicular presynaptic terminals, 5-HT1B and GABAB receptors colocalize. GABAB receptors inhibit Ca21 entry, whereas 5-HT1B receptors target SNARE complexes. We demonstrate in male and female rats that GABAB receptors alter Pr, whereas 5-HT1B receptors reduce evoked cleft glutamate concentrations, allowing differential inhibition of AMPAR and NMDAR EPSCs. This reduction in cleft glutamate concentration was confirmed by imaging glutamate release using a genetic sensor (iGluSnFR). Simulations of glutamate release and postsynaptic glutamate receptor currents were made. We tested effects of changes in vesicle numbers undergoing fusion at single synapses, relative placement of fusing vesicles and postsynaptic receptors, and the rate of release of glutamate from a fusion pore. Experimental effects of Pr changes, consistent with GABAB receptor effects, were straightforwardly represented by changes in numbers of synapses. The effects of 5-HT1B receptor-mediated inhibition are well fit by simulated modulation of the release rate of glutamate into the cleft. Colocalization of different actions of GPCRs provides synaptic integration within presynaptic terminals. Train-dependent presynaptic Ca2+ accumulation forces frequency-dependent recovery of neurotransmission during 5-HT1B receptor activation. This is consistent with competition between Ca2+-synaptotagmin and Gβc at SNARE complexes. Thus, stimulus trains in 5-HT1B receptor agonist unveil dynamic synaptic modulation and a sophisticated hippocampal output filter that itself is modulated by colocalized GABAB receptors, which alter presynaptic Ca2+. In combination, these pathways allow complex presynaptic integration. [ABSTRACT FROM AUTHOR]