TRATTAMENTO CRONICO ED ASTINENZA DA NICOTINA: EFFETTI IN VIVO SULL'ESPRESSIONE DEI RECETTORI COLINERGICI NICOTINICI E GLUTAMMATERGICI NEL SNC DI RODITORI

Like many other drugs of abuse, nicotine has two effects that contribute to its additive properties: its reinforcing or rewarding properties, and the aversive abstinence syndrome that develops when it is precipitously withdrawn. These effects are due to neural adaptations that change whole cell physiology and behavior and are mainly due to nicotine\u2019s interactions with neural nicotinic acetylcholine receptors. Mice with different a4 and b2 subunit expression (wild-type, heterozygotes and null-mutant for each gene) where chronically treated with one of four doses of nicotine (0, 0.25, 1 or 4 mg/kg/h), than the mice treated with higher dose were exposed to 1, 4 or 14 days of withdrawal. Chronic nicotine treatment increases the density of nicotinic acetylcholine receptor (nAChR) binding sites both in wild-type and heterozygotes. These increases are most pronounced for the a4b2* nAChR subtype. The extent of the increase is dependent on the dose of nicotine administered and is saturable. Furthermore, the magnitude of the increase varies among brain regions. In the cortex nicotine also increases the expression of the a4b2 subtype with the (a4)2(b2)3 stoichiometry. a4 and b2 KO mice have little detectable nicotinic receptors that contain the a3b4 subunits and these receptors were unaffected by chronic nicotine treatment. We also analysed the expression of glutamatergic receptor subunits at the end of nicotine treatment (4mg/kg/h) and after 1, 4 or 14 days of withdrawal in two areas of mesocorticolimbic dopaminergic system: the Striatum and the Ventral Tegmental Area (VTA) . We found that after chronic treatment, in VTA synaptosomes there is a selective upregulation of GluA2/3 AMPA receptors whereas during withdrawal there is a significative increase in AMPA GluA1 receptors and NMDA receptors containing GluN1 and GluN2A subunits. In striatal synaptosomes after nicotine treatment there is a significant decrease of GluA2/3 AMPA receptors that is maintained during the 14 days nicotine withdrawal. At 4 days withdrawal there is a transient decrease in GluA1 AMPA and GluN1 and GluN2A containing NMDA receptors Our data suggest that ionotropic glutamate receptors are up regulated in the VTA early during nicotine withdrawal whereas they are down regulated in the striatum. These findings suggest that chronic nicotine selectively changes the levels of ionotropic glutamate receptor subunits in a brain region-specific manner

The Chemokine CCL2 Mediates the Seizure-enhancing Effects of Systemic Inflammation

Epilepsy is a chronic disorder characterized by spontaneous recurrent seizures. Brain inflammation is increasingly recognized as a critical factor for seizure precipitation, but the molecular mediators of such proconvulsant effects are only partly understood. The chemokine CCL2 is one of the most elevated inflammatory mediators in patients with pharmacoresistent epilepsy, but its contribution to seizure generation remains unexplored. Here, we show, for the first time, a crucial role for CCL2 and its receptor CCR2 in seizure control. We imposed a systemic inflammatory challenge via lipopolysaccharide (LPS) administration in mice with mesial temporal lobe epilepsy. We found that LPS dramatically increased seizure frequency and upregulated the expression of many inflammatory proteins, including CCL2. To test the proconvulsant role of CCL2, we administered systemically either a CCL2 transcription inhibitor (bindarit) or a selective antagonist of the CCR2 receptor (RS102895). We found that interference with CCL2 signaling potently suppressed LPS-induced seizures. Intracerebral administration of anti-CCL2 antibodies also abrogated LPS-mediated seizure enhancement in chronically epileptic animals. Our results reveal that CCL2 is a key mediator in the molecular pathways that link peripheral inflammation with neuronal hyperexcitability

Improving water use efficiency in vertical farming: Effects of growing systems, far-red radiation and planting density on lettuce cultivation

Vertical farms (VFs) are innovative urban production facilities consisting of multi-level indoor systems equipped with artificial lighting in which all the environmental conditions are controlled independently from the external climate. VFs are generally provided with a closed loop fertigation system to optimize the use of water and nu-trients. The objective of this study, performed within an experimental VF at the University of Bologna, was to quantify the water use efficiency (WUE, ratio between plant fresh weight and the volume of water used) for a lettuce (Lactuca sativa L.) growth cycle obtained in two different growing systems: an ebb-and-flow substrate culture and a high pressure aeroponic system. Considering the total water consumed (water used for irrigation and climate management), WUE of ebb-and-flow and aeroponics was 28.1 and 52.9 g L-1 H2O, respectively. During the growing cycle, the contribution generated by the recovery of internal air moisture from the heating, ventilation and air conditioning (HVAC) system, was quantified. Indeed, by recovering water from the dehu-midifier, water use decreases dramatically (by 67 %), while WUE increased by 206 %. Further improvement of WUE in the ebb-and-flow system was obtained through ameliorated crop management strategies, in particular, by increasing planting densities (e.g., 153, 270 and 733 plants m-2) and by optimizing the light spectrum used for plant growth (e.g., adjusting the amount of far-red radiation in the spectrum). Strategies for efficient use of water in high-tech urban indoor growing systems are therefore proposed

Optimal photoperiod for indoor cultivation of leafy vegetables and herbs

In Vertical Farms with Artificial Lighting (VFALs), optimal light management is a crucial determinant of both economic and environmental viability. Applications of LED technologies to plant cultivation are still recent, and research has to date mainly targeted the definition of optimal spectral and light intensity features. On the other hand, despite the relevant implications on production costs, literature on optimal photoperiod management is to date limited. Indeed, the number of hours per day correlates with the total light supplied to the crop \u2013 expressed as Daily Light Integral (DLI) \u2013 and the associated energetic costs. The present study aims at defining how photoperiods of 16 h d-1 (DLI= 14.4 mol m-2 d-1), 20 h d-1 (DLI= 18 mol m-2 d-1) and 24 h d-1 (DLI= 21.6 mol m-2 d-1)of light affect growth performances and resource use efficiency in leafy vegetables and herbs, represented by lettuce (Lactuca sativa L.), basil (Ocimum basilicum L.), rocket (Eruca sativa Mill.), and chicory (Cichorium intybus L.). Plants were cultivated indoor under a red (R) and blue (B) LED light (RB=3, photosynthetic photon flux density (PPFD)= 250 mmol m-2 s-1). Photoperiod variations\u2019 effects differed according to the considered plant species. In lettuce and chicory, the adoption of a DLI of 14.4 mol m-2 d-1 at 16 h d-1 photoperiod resulted in a greater plants fresh biomass and leaf area, which also contributed to generally obtain higher energy use efficiency (fresh biomass per unit of electricity input), light use efficiency (dry biomass per unit of light input) and, in chicory, also water use efficiency (fresh biomass per liter of water consumed). Contrarily, although photoperiod variations did not affect basil and rocket growth parameters (e.g., fresh biomass and leaf area) and the plant capacity to transform resources (e.g., water use efficiency and light use efficiency), energy use efficiency in basil also presented a downward trend in response to growing DLI. Accordingly, the adoption of a DLI of 14.4 mol m-2 d-1 at 16 h d-1 photoperiod resulted to be the optimal option among the ones tested in the presented research

Analysis of the RLMS Adaptive Beamforming Algorithm Implemented with Finite Precision

This paper studies the influence of the use of finite wordlength on the operation of the RLMS adaptive beamformingalgorithm. The convergence behavior of RLMS, based on the minimum mean square error (MSE), is analyzed for operation with finite precision. Computer simulation results verify that a wordlength of nine bits is sufficient for the RLMS algorithm to achieve performance close to that provided by full precision. The performance measures used include residual MSE, rate of convergence, error vector magnitude (EVM), and beam pattern. Based on all these measures, it is shown that the RLMS algorithm outperforms other earlier algorithms, such as least mean square (LMS), recursive least square (RLS), modified robust variable step size (MRVSS) and constrained stability LMS (CSLMS)

Measurement of Gamma(phi -> eta' gamma)/Gamma(phi -> eta gamma) and the pseudoscalar mixing angle

We have measured the radiative decays phi -> eta gamma, phi ->etaprime gamma selecting pi+ pi- gamma gamma gamma final state in a sample of about 5 times 10^7 phi mesons produced at the Frascati phi factory DAFNE. We obtain Gamma(phi -> etaprime gamma)/Gamma(phi -> eta gamma)=(4.70 +- 0.47 +- 0.31) times 10^-3. From this result we derive new accurate values for the branching ratio BR(phi ->etaprime gamma) = (6.10 +- 0.61 +- 0.43) times 10^-5, and the mixing angle of pseudoscalar mesons in the flavour basis phi_P=(41.8 +1.9 -1.6) degrees.Comment: Submitted to Phys. Lett.

Search for spontaneous muon emission from lead nuclei

We describe a possible search for muonic radioactivity from lead nuclei using the base elements ("bricks" composed by lead and nuclear emulsion sheets) of the long-baseline OPERA neutrino experiment. We present the results of a Monte Carlo simulation concerning the expected event topologies and estimates of the background events. Using few bricks, we could reach a good sensitivity level.Comment: 12 pages, 4 figure