Francesco Moccia

NAADP activates a Ca2+ current that is dependent on F-actin cytoskeleton

Nicotinic acid adenine dinucleotide phosphate (NAADP) is involved in the Ca2+ response observed at fertilization in several species, including starfish. In this study, we have employed Ca2+ imaging and the single‐electrode voltage‐clamp technique to investigate whether the NAADP‐mediated Ca2+ entry discovered in our laboratory in starfish oocytes was underlain by a membrane current and whether the response to NAADP required an intact cytoskeleton. Uncaging of preinjected NAADP evoked a cortical Ca2+ flash that was followed by the spreading of the wave to the remainder of the cell. No Ca2+ increase was detected in Ca2+‐free sea water. Under voltage‐clamp conditions, the photoliberation of NAADP activated an inward rectifying membrane current, which reversed at potentials more positive than +50 mV and was abolished by removal of Ca2+ but not of Na+. The current was affected by preincubation with verapamil, SK&F 96356, and thapsigargin but not by preinjection of heparin, 8‐NH2‐ cyclic ADP‐ribose, or both antagonists. The membrane current and the Ca2+ wave were inhibited by latrunculin‐A and jasplakinolide, which depolymerize and stabilize actin cytoskeleton, respectively. These data offer the first demonstration that NAADP initiates a Ca2+ sweep by activating a Ca2+‐permeable membrane current that requires an intact F‐actin cytoskeleton as other Ca2+‐permeable currents, such as ICRAC and IARC.

Pre-and postsynaptic excitation and inhibition at octopus optic lobe photoreceptor terminals; implications for the function of the 'presynaptic bags'

Synaptic transmission was examined in the plexiform zone of Octopus vulgaris optic lobes using field‐potential recording from optic lobe slices. Stimulation of the optic nerve produced pre‐ and postsynaptic field potentials. Transmission was abolished in calcium‐free seawater, L‐ glutamate or the AMPA/Kainate receptor blocker CNQX (EC50, 40 µm), leaving an intact presynaptic field potential. ACh markedly reduced or blocked and d‐tubocurarine augmented both pre‐ and postsynaptic field potentials, while α‐bungarotoxin and atropine were without effect. Paired‐pulse stimulation showed short‐term depression of pre‐ and postsynaptic components with a half‐time of recovery of ∼ 500 ms. The depression was partially relieved in the presence of d‐tubocurarine (half‐time of recovery, 350 ms). No long‐term changes in synaptic strength were induced by repetitive stimulation. A polyclonal antibody raised against a squid glutamate receptor produced positive staining in the third radial layer of the plexiform zone. No positive staining was observed in the other layers. Taking into account previous morphological data and our results, we propose that the excitatory terminations of the photoreceptors are in the innermost layer of the plexiform zone where the transmitter is likely to be glutamate and postsynaptic receptors are AMPA/kainate‐like. Thus, the function of the terminal bags is to provide a location for a presynaptic cholinergic inhibitory shunt. The results imply that this arrangement provides a temporal filter for visual processing and enhances the perception of moving vs. stationary objects.

Flood hazard: planning approach to risk mitigation

Control of risks associated with floods in recent years has a central role in urban planning scientific research. This is related to the increased incidence of these phenomena whose the root cause was found in the greater frequency of extreme rainfall events as a result of climate change. In Italy the phenomenon became dramatic because of the numerous human casualties that occur each year. Without prejudice to the need for interventions that effectively act on climate change, there is a need to provide interventions to mitigate the consequences in the short-term. The Department of Urban Planning at Naples University has conducted a thorough research on the case, objectively verifying the impact that human activity has on the dramatic consequences of rainfall events, also highlighting the lack of efficiency of the traditional mitigation measures based on the construction of huge detention basins dug in the ground. This is due to three main reasons: such interventions require financial investments that local communities often do not have; the creation of detention basins cause the removal of large quantities of soil for agricultural use; the continuous increase in impervious surfaces due to urbanization implies the need to cope with the masses of water ever more impressive and therefore the dry ponds already created quickly become insufficient. The research proposes some interventions and best practices that, if adopted, can radically reduce the impact of extreme rainfall on public safety, enabling an efficient participation of private capital in investments through the use of leverage financial and fiscal incentives.

Strategies of Landscape Restoration and City Naturalizing

The international attention for climate change has marked a turn for urban planning, and demands for a radical change of direction. It is necessary to adopt an active approach aiming to an ecological urban reform that identifies natural alterations of urban settlements and works for the restoration of natural balance. Assuming such an approach is an even more difficult challenge in urban areas, where urbanization processes frequently modified natural cycles, erasing the bonds with natural environment.Recognizing the importance of the water cycle for the life of urban ecosystems entails leaving water disposal methods aside and working hard to bring the hydrographical system of urbanized areas back to the surface, allowing the retrieval of the whole complex of ecosystem services related to environment mosaics in which water is present.The research is concerned with the eastern plain of Naples - originally a marshland, progressively urbanized for industrial purposes during the XIX and XX centuries, nowadays degraded after the closure of most of the factories - where environmental decline can be interpreted as an opportunity for testing water-centered strategies of landscape restoration and naturalizing in urban contexts.

Planning Knowledge and Process for Strategies of Participatory River Contracts

In the river contract process, an ever more widespread participatory policy in Europe, the first step never enough considered is the construction of an appropriate knowledge and a streamlined planning process. The main challenge to face is the collection of multidisciplinary requirements coming from the different domains that can contribute to the analysis of the river basin, thus overcoming shortfalls and problems that can arise in the process and stimulating change management scenarios. In this complex setting, the planner’s perspective seems to be the most appropriate to call sciences to offer their contributions for the aims of the program because they must fit in a multi-actorial decision process aimed to pragmatic actions. According to this perspective, some other questions are added to the consolidated knowledge on the river basin: from the study of the hydrographic network and reports on soil quality to the analysis of urban and social systems, a focus on connections and interactions, and a study on economic activities. This knowledge comes from heterogeneous sources, such as information officially produced by government bodies, found in the scientific literature, or resulting from oral stories and interviews.