Postsynaptic actions of excitatory amino acids investigated with flash photolysis

Flash photolysis and whole cell patch clamp technique were combined with microspectrofluorimetry of calcium to study the role of inositol trisphosphate as a second messenger, and the role of L-glutamate as a neurotransmitter. Inactive photolabile analogous of inositol trisphosphate, caged InsP3, and fluorescent calcium indicators, Fluo-3 or Furaptra, was introduced into single cells via the whole-cell patch pipette. Astrocytes and neurones from primary cultures of cerebellar granule cells, hippocampal pyramidal cells, striatal neurones, and dorsal root ganglion neurones, and Purkinje cells from acutely prepared thin slices of the cerebellum were voltage clamped (holding potential -70mV). A 1ms pulse of near UV (300-350nm, 100mJ) was used to photolytically release a known concentration of InsP3 in the cytosol, and the changes in the intracellular free calcium concentration, [Ca2+], and conductance monitored. The results may be summarised as follows: (1) Photolytic release of InsP3 (100nM-30μM) in cultured neurones did not alter [Ca2+] or the membrane conductance. In glial cells from the same preparations, however, a rise in [Ca2+] was observed following intracellular release of InsP3 (0.2-5μM). The concentrations of InsP3 required to mobilise calcium in astrocytes is similar to that found in peripheral tissue. (2) Photolytic release of InsP3 (9-76μM) in voltage clamped Purkinje neurones in acutely prepared thick slices of the cerebellum resulted in a large increase in [Ca2+], often reaching 30μM when calibrated with Furaptra, and at the same time an outward current (200-900pA) in the presence or absence of external calcium. The outward current was the result of an increase of the membrane conductance to potassium ions, and under current clamp conditions hyperpolarised the cell to approximately -85mV. The responses occurred with a latency that decreased from a few hundred ms at low (9μM) to 10000X less potent at the NMDA, and >50X at the non-NMDA receptors. When irradiated with a 1ms pulse of near UV light (300-350nm, 100mJ) it cleaved to release L-glutamate, 2-nitrosoacetophenone, and carbon dioxide with a quantum yield of 50%. Neither caged glutamate (1mM) nor its photolysis by-products had any potency as an antagonist at the excitatory amino acid sites. The rate of photolysis was found to have a half time of about 50ms at pH7, too slow to allow for studies of rate of receptor activation. The rate of photolysis, however, is pH dependent increasing 10 fold with one pH unit drop. The ability of the squid giant synapse to withstand acidic conditions was taken advantage of, and L-glutamate was photolytically released from caged glutamate equilibrated with the synapse at pH5.5. This abrupt release of L-glutamate elicited action potentials in the 3rd order fibre of the giant synapse providing good evidence of the role of L-glutamate as a neurotransmitter at this synapse

Metric-Based Random Iteration Algorithm For Resource Management In Non-Orthogonal Multiple Access Of Wireless Networks

In this paper, we focus on joint subcarrier and power allocation in the uplink of an NOMA system. The main taxonomy of NOMA is presented by focusing on the following categories: power-domain and code-domain NOMA. Then a novel radio resource management framework is presented metric-based random iteration Algorithm (MRIA) for uplink and downlink transmissions. This method determine target subject that it is Number of scheduled users.  

Resource Management Optimally in Non-Orthogonal Multiple Access Networks for Fifth-Generation by using Game-Theoretic

In this paper, several number of users were optimized in resource allocation management by applying the game theory User-sub-channel-Soap Matching Algorithm (USMA) in Non-Orthogonal Multiple Access (NOMA) for fifth-generation wireless networks. multiple access users can be increased up to 63 users in NOMA. This method reduces interference between users, which include costs, and resource to access for other users

The effect of communications system on organizational conflicts, case study: automobile press parts department

Nowadays, organizations are characterized by direct relation between perception of different aspect and patterns of human relations with staff performance and human resources (HR) management. To confronting environmental threats companies need to identify their internal capacities and capabilities, improve strengths and compensate their weaknesses. Effective and correct transfer of message or communication process, in other words, is one of the main aspects of staffs behavior in organization. The present work investigates roles of organizational communication system on the conflicts (case study: Iran Khodro, press machines parts department). To this end, a questionnaire was designed taking advice from experts and specialists and results were examined using statistics tests and methods. The paper is concluded by presenting recommendations to overcome conflicts and reform organization communication system in Iran Khodro Press Parts Department

IDENTIFYING THE RELATIONSHIP BETWEEN THE SKILLS OF STRATEGIC THINKING AND MULTIPLE INTELLIGENCES AMONG BUSINESS AND SALE MANAGERS

ABSTRACT In the changing world of today, understanding the conditions and predicting their trends is the only way of the organizations for impowerment in order to exceed their rivals. This doesn't occur, unless the managers with high strategic abilities are used in the rganizations.Therefore, this study aims to use multiple intelligence theory due to its importance for measuring different human capabilities and personal differences. The results can help the organizations in selecting the managers with high abilities of the related intelligences with strategic thinking to provide a competitive advantage for their organizations. According to the findings, there was a significant correlation between 3 out of 7 intelligences of Gardner (visual/spatial, logical/mathematic, interpersonal) and strategic thinking ability

Navigating clues to success in academia

Academic success and how to achieve it takes diverse forms, depending on who’s asked. We suggest that happiness, impact, and longevity can be achieved with professional effort and support that balances the toil and joys of one’s chosen path.<br/

Design and Initial Characterization of a Small Near-Infrared Fluorescent Calcium Indicator

Near-infrared (NIR) genetically encoded calcium indicators (GECIs) are becoming powerful tools for neuroscience. Because of their spectral characteristics, the use of NIR GECIs helps to avoid signal loss from the absorption by body pigments, light-scattering, and autofluorescence in mammalian tissues. In addition, NIR GECIs do not suffer from cross-excitation artifacts when used with common fluorescent indicators and optogenetics actuators. Although several NIR GECIs have been developed, there is no NIR GECI currently available that would combine the high brightness in cells and photostability with small size and fast response kinetics. Here, we report a small FRET-based NIR fluorescent calcium indicator iGECInano. We characterize iGECInano in vitro, in non-neuronal mammalian cells, and primary mouse neurons. iGECInano demonstrates the improvement in the signal-to-noise ratio and response kinetics compared to other NIR GECIs.Peer reviewe

Restoration of Harmane Induced Memory Consolidation Deficit by Alpha-lipoic Acid in Male Mice

Introduction: there has been a growing number of publications focusing on the effect of beta-carbolines (e.g., harmane) on cognitive behaviors such as different stages of memory formation process. Moreover, several studies have stated that Alpha-lipoic acid (ALA) induces some molecular pathways effects including antioxidant effect and reduction of inflammation process. Thus, in the lines that follow, the question of whether ALA could alter memory consolidation deficit caused by harmane in the male NMRI mice will be addressed. Materials and Methods: The data for this study were collected by step-down inhibitory avoidance task with one trial protocol for evaluation of memory consolidation. The ALA (35 mg/kg) was injected intraperitoneally immediately after training followed by subthreshold and effective doses of harmane (2.5, 5 and 10 mg/kg) with 15-minute interval period. Results: The results show that post-training injection of the highest dose of harmane (10 mg/kg) lowers step-down latency, indicating the amnesia induced by harmane (P&lt;.001). In addition, similar injection of subthreshold dose of ALA (35 mg/kg), 15 minutes before injection of subthreshold and effective doses of harmane, restores step-down latency caused by higher dose of harmane (P&lt;.001) without its effect on the responses induced by subthreshold doses of harmane, indicating benefit effect of ALA on amnesia induced by harmane. Conclusion: An implication of this study is the possibility that ALA can reverse the amnesia induced by harmane. Therefore, future studies on this topic such as molecular mechanisms are recommended. &nbsp