Solving unsolved rare neurological diseases-a Solve-RD viewpoint.

Funder: Durch Princess Beatrix Muscle Fund Durch Speeren voor Spieren Muscle FundFunder: University of Tübingen Medical Faculty PATE programFunder: European Reference Network for Rare Neurological Diseases | 739510Funder: European Joint Program on Rare Diseases (EJP-RD COFUND-EJP) | 44140962

GABA-Induced Cl− Current in Cultured Embryonic Human Dorsal Root Ganglion Neurons

γ-Aminobutyric acid (GABA)-activated channels in embryonic (5–8 wk old) human dorsal root ganglion (DRG) neurons in dissociated culture were characterized by whole cell and single-channel techniques. All DRG neurons when held at negative holding membrane potentials displayed inward current to micromolar concentrations of GABA applied by pressure pulses from closely positioned micropipettes. The current was directly proportional to the concentration of GABA (EC50, 111 μM; Hill coefficient, 1.7). DRG neurons also responded to micromolar concentrations of pentobarbital and alphaxalone but not to cis-4-aminocrotonic acid (CACA), glycine, or taurine. Baclofen (100 μM) affected neither the holding currents nor K+ conductance (when patch pipettes were filled with 130 mM KCl) caused by depolarizing pulses. Whole cell GABA-currents were blocked by bicuculline, picrotoxin, and t-butylbicyclophosphorothionate (TBPS; all at 100 μM). The reversal potential of whole cell GABA-currents was close to the theoretical Cl− equilibrium potential, shifting with changes in intracellular Cl− concentration in a manner expected for Cl−-selective channels. The whole cell I-V curve for GABA-induced currents demonstrated slight outward rectification with nearly symmetrical outside and inside Cl− concentrations. Spectral analysis of GABA-induced membrane current fluctuations showed that the kinetic components were best fitted by a triple Lorentzian function. The apparent elementary conductance for GABA-activated Cl− channels determined from the power spectra was 22.6 pS. Single-channel recordings from cell-attached patches with pipettes containing 10 μM GABA indicated that GABA-activated channels have a main and a subconductance level with values of 30 and 19 pS, respectively. Mean open and closed times of the channel were characterized by two or three exponential decay functions, suggesting two or three open channel states and two closed states. Single channels showed a lack of rectification. The actions of GABA on cultured human embryonic DRG neurons are mediated through the activation of GABAA receptors with properties corresponding to those found in the CNS of human and other mammalian species but differing from those of cultured human adult DRG neurons

Exploring the components of career well-being and the emotions associated with significant career experiences

This study aimed to identify the main features of career well-being and the emotions people experience as they navigate their careers. Data from 89 individuals working in various occupations suggested seven features of career well-being involving the following: career transitions, interpersonal relationships, relationship with the organization, work performance, sense of purpose, learning and development, and work—life issues. Fifteen positive and 24 negative emotions were reported, and several career experiences were associated with wide-ranging emotions. Moving to a new role was particularly likely to involve a mixture of positive and negative emotions. Participants frequently gave examples of interpersonal difficulties as negative career experiences, and these sometimes led to profound feelings of unhappiness and worthlessness. Implications for career counseling and career management are discussed

Alphaxalone Activates a Cl −

Whole cell and cell-attached patch-clamp techniques characterized the neurosteroid anesthetic alphaxalone’s (5α-pregnane-3α-ol-11,20-dione) effects on GABAAreceptors and on Cl− currents in cultured embryonic (5- to 8-wk old) human dorsal root ganglion neurons. Alphaxalone applied by pressure pulses from closely positioned micropipettes failed to potentiate the inward Cl− currents produced by application of GABA. In the absence of GABA, alphaxalone (0.1–5.0 μM) directly evoked inward currents in all dorsal root ganglion neurons voltage-clamped at negative membrane potentials. The amplitude of the current was directly proportional to the concentration of alphaxalone (Hill coefficient 1.3 ± 0.15). The alphaxalone-induced whole cell current was carried largely by Cl− ions. Its reversal potential was close to the theoretical Cl− equilibrium potential, changing with a shift in the external Cl−concentration as predicted by the Nernst equation for Cl−ions. And because the alphaxalone-current was not suppressed by the competitive GABAA receptor antagonist bicuculline or by the channel blockers picrotoxin and t-butylbicyclophosphorothionate (TBPS; all at 100 μM), it did not appear to result from activation of GABAAreceptors. In contrast to GABA-currents in the same neurons, the whole cell current-voltage curves produced in the presence of alphaxalone demonstrated strong inward rectification with nearly symmetrical bath and pipette Cl− concentrations. Fluctuation analysis of the membrane current variance produced by 1.0 μM alphaxalone showed that the power density spectra were best fitted to double Lorentzian functions. The elementary conductance for alphaxalone-activated Cl− channels determined by the relationship between mean amplitude of whole cell current and variance was 30 pS. Single-channel currents in cell-attached patches when the pipette solution contained 10 μM alphaxalone revealed a single conductance state with a chord conductance of ∼29 pS. No subconductance states were seen. The current-voltage determinations for the single-channels activated by alphaxalone demonstrated a linear relationship. Mean open and shut times of single alphaxalone-activated channels were described by two exponential decay functions. Taken together, the results indicate that in embryonic human DRG neurons, micromolar concentrations of alphaxalone directly activate Cl− channels whose electrophysiological and pharmacological properties are distinct from those of Cl−channels associated with GABAA receptors

Leader Deception Influences on Leader–Member Exchange and Subordinate Organizational Commitment

Deception is a common and daily occurrence in organizations. Despite this, little is known about how leader deception influences follower perceptions and commitment to the leader and the broader organization. This laboratory experiment uses a low-fidelity simulation task to investigate the effects of leader deception on follower perceptions of leader–member exchange (LMX) and follower commitment to the organization. Moderating effects of financial outcomes that resulted from deception, or who gained from deception, were also tested. Results showed negative effects of leader deception on follower LMX perceptions and affective commitment. Leader financial gain worsened the effects of leader deception on LMX compared with organizational financial gain. Implications of these findings are discussed

GABA-Induced Cl −

γ-Aminobutyric acid (GABA)-activated channels in embryonic (5–8 wk old) human dorsal root ganglion (DRG) neurons in dissociated culture were characterized by whole cell and single-channel techniques. All DRG neurons when held at negative holding membrane potentials displayed inward current to micromolar concentrations of GABA applied by pressure pulses from closely positioned micropipettes. The current was directly proportional to the concentration of GABA (EC50, 111 μM; Hill coefficient, 1.7). DRG neurons also responded to micromolar concentrations of pentobarbital and alphaxalone but not to cis-4-aminocrotonic acid (CACA), glycine, or taurine. Baclofen (100 μM) affected neither the holding currents nor K+ conductance (when patch pipettes were filled with 130 mM KCl) caused by depolarizing pulses. Whole cell GABA-currents were blocked by bicuculline, picrotoxin, and t-butylbicyclophosphorothionate (TBPS; all at 100 μM). The reversal potential of whole cell GABA-currents was close to the theoretical Cl− equilibrium potential, shifting with changes in intracellular Cl− concentration in a manner expected for Cl−-selective channels. The whole cell I-V curve for GABA-induced currents demonstrated slight outward rectification with nearly symmetrical outside and inside Cl− concentrations. Spectral analysis of GABA-induced membrane current fluctuations showed that the kinetic components were best fitted by a triple Lorentzian function. The apparent elementary conductance for GABA-activated Cl− channels determined from the power spectra was 22.6 pS. Single-channel recordings from cell-attached patches with pipettes containing 10 μM GABA indicated that GABA-activated channels have a main and a subconductance level with values of 30 and 19 pS, respectively. Mean open and closed times of the channel were characterized by two or three exponential decay functions, suggesting two or three open channel states and two closed states. Single channels showed a lack of rectification. The actions of GABA on cultured human embryonic DRG neurons are mediated through the activation of GABAA receptors with properties corresponding to those found in the CNS of human and other mammalian species but differing from those of cultured human adult DRG neurons