53 research outputs found
Planning and imagining the future on the Isle of Sheppey
Thinking about the future can be daunting, especially for those young people who need to decide about their careers and commitments after college. Giulia Carabelli and Dawn Lyon, research associate and principal investigator of the Imagine Sheppey Fast Forward project, University of Kent, discuss what they discovered through exploring how young people living on the Isle of Sheppey (Kent) imagine their futures
Is a Quantum Biosensing Revolution Approaching? Perspectives in NVâAssisted Current and Thermal Biosensing in Living Cells
none8openPetrini, Giulia; Moreva, Ekaterina; Bernardi, Ettore; Traina, Paolo; Tomagra, Giulia; Carabelli, Valentina; Degiovanni, Ivo Pietro; Genovese, MarcoPetrini, Giulia; Moreva, Ekaterina; Bernardi, Ettore; Traina, Paolo; Tomagra, Giulia; Carabelli, Valentina; Degiovanni, Ivo Pietro; Genovese, Marc
Simultaneous multisite detection of quantal release from PC12 cells using micro graphitic-diamond multi electrode arrays
Two firing modes and well-resolved Na+, K+, and Ca2+ currents at the cell-microelectrode junction of spontaneously active rat chromaffin cell on MEAs
We recorded spontaneous extracellular action potentials (eAPs) from rat chromaffin cells (CCs) at 37 °C using microelectrode arrays (MEAs) and compared them with intracellularly recorded APs (iAPs) through conventional patch clamp recordings at 22 °C. We show the existence of two distinct firing modes on MEAs: aâ~â4 Hz irregular continuous firing and a frequent intermittent firing mode where periods of high-intraburst frequency (~â8 Hz) ofâ~â7 s duration are interrupted by silent periods ofâ~â12 s. eAPs occurred either as negative- or positive-going signals depending on the contact between cell and microelectrode: either predominantly controlled by junction-membrane ion channels (negative-going) or capacitive/ohmic coupling (positive-going). Negative-going eAPs were found to represent the trajectory of the Na(+), Ca(2+), and K(+) currents passing through the cell area in tight contact with the microelectrode during an AP (point-contact junction). The inward Nav component of eAPs was blocked by TTX in a dose-dependent manner (IC(50)â~â10 nM) while the outward component was strongly attenuated by the BK channel blocker paxilline (200 nM) or TEA (5 mM). The SK channel blocker apamin (200 nM) had no effect on eAPs. Inward Nav and Cav currents were well-resolved after block of Kv and BK channels or in cells showing no evident outward K(+) currents. Unexpectedly, on the same type of cells, we could also resolve inward L-type currents after adding nifedipine (3 ΌM). In conclusion, MEAs provide a direct way to record different firing modes of rat CCs and to estimate the Na(+), Ca(2+), and K(+) currents that sustain cell firing and spontaneous catecholamines secretion
Alpha-synuclein oligomers alter the spontaneous firing discharge of cultured midbrain neurons
NanodiamondâQuantum Sensors Reveal Temperature Variation Associated to Hippocampal Neurons Firing
Micro graphite-patterned diamond sensors: Towards the simultaneous in vitro detection of molecular release and action potentials generation from excitable cells
Alpha-synuclein oligomers alter the spontaneous firing discharge of cultured midbrain neurons
The aim of this work was to monitor the effects of extracellular α-synuclein on
the firing activity of midbrain neurons dissociated from substantia nigra TH-GFP
mice embryos and cultured on microelectrode arrays (MEA). We monitored the
spontaneous firing discharge of the network for 21 days after plating and the
role of glutamatergic and GABAergic inputs in regulating burst generation and
network synchronism. Addition of GABAA, AMPA and NMDA antagonists did not
suppress the spontaneous activity but allowed to identify three types of neurons that
exhibited different modalities of firing and response to applied L-DOPA: high-rate
(HR) neurons, low-rate pacemaking (LR-p), and low-rate non-pacemaking (LR-np)
neurons. Most HR neurons were insensitive to L-DOPA, while the majority of LR-
p neurons responded with a decrease of the firing discharge; less defined was the
response of LR-np neurons. The effect of exogenous α-synuclein (α-syn) on the
firing discharge of midbrain neurons was then studied by varying the exposure
time (0â48 h) and the α-syn concentration (0.3â70 ÎŒM), while the formation of
α-syn oligomers was monitored by means of AFM. Independently of the applied
concentration, acute exposure to α-syn monomers did not exert any effect on
the spontaneous firing rate of HR, LR-p, and LR-np neurons. On the contrary,
after 48 h exposure, the firing activity was drastically altered at late developmental
stages (14 days in vitro, DIV, neurons): α-syn oligomers progressively reduced the
spontaneous firing discharge (IC50 = 1.03 ÎŒM), impaired burst generation and
network synchronism, proportionally to the increased oligomer/monomer ratio.
Different effects were found on early-stage developed neurons (9 DIV), whose firing
discharge remained unaltered, regardless of the applied α-syn concentration and
the exposure time. Our findings unravel, for the first time, the variable effects of
exogenous α-syn at different stages of midbrain network development and provide
new evidence for the early detection of neuronal function impairment associated to
aggregated forms of α-syn
Alpha-synuclein oligomers alter the spontaneous firing discharge of cultured midbrain neurons
The aim of this work was to monitor the effects of extracellular α-synuclein on the firing activity of midbrain neurons dissociated from substantia nigra TH-GFP mice embryos and cultured on microelectrode arrays (MEA). We monitored the spontaneous firing discharge of the network for 21 days after plating and the role of glutamatergic and GABAergic inputs in regulating burst generation and network synchronism. Addition of GABAA, AMPA and NMDA antagonists did not suppress the spontaneous activity but allowed to identify three types of neurons that exhibited different modalities of firing and response to applied L-DOPA: high-rate (HR) neurons, low-rate pacemaking (LR-p), and low-rate non-pacemaking (LR-np) neurons. Most HR neurons were insensitive to L-DOPA, while the majority of LR-p neurons responded with a decrease of the firing discharge; less defined was the response of LR-np neurons. The effect of exogenous α-synuclein (α-syn) on the firing discharge of midbrain neurons was then studied by varying the exposure time (0â48 h) and the α-syn concentration (0.3â70 ÎŒM), while the formation of α-syn oligomers was monitored by means of AFM. Independently of the applied concentration, acute exposure to α-syn monomers did not exert any effect on the spontaneous firing rate of HR, LR-p, and LR-np neurons. On the contrary, after 48 h exposure, the firing activity was drastically altered at late developmental stages (14 days in vitro, DIV, neurons): α-syn oligomers progressively reduced the spontaneous firing discharge (IC50 = 1.03 ÎŒM), impaired burst generation and network synchronism, proportionally to the increased oligomer/monomer ratio. Different effects were found on early-stage developed neurons (9 DIV), whose firing discharge remained unaltered, regardless of the applied α-syn concentration and the exposure time. Our findings unravel, for the first time, the variable effects of exogenous α-syn at different stages of midbrain network development and provide new evidence for the early detection of neuronal function impairment associated to aggregated forms of α-syn
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