Synthesis and biological evaluation of benzodiazepines containing a pentafluorosulfanyl group

The widely used pentafluorosulfanyl group (SF5) was deployed as a bioisosteric replacement for a chloro-group in the benzodiazepine diazepam (Valium™). Reaction of 2-amino-5-pentafluorosulfanyl-benzophenone with chloroacetyl chloride followed by hexamethylenetetramine, in the presence of ammonia, led to 7-sulfurpentafluoro-5-phenyl-1H-benzo[1,4]diazepin-2(3H)-one (2c). The latter was able to undergo a Pd-catalysed ortho-arylation, demonstrating that these highly fluorinated benzodiazepines can be further modified to form more complicated scaffolds. The replacement of Cl by the SF5 group, led to a loss of potency for potentiating GABAA receptor activation, most likely because of a lost ligand interaction with His102 in the GABAA receptor α subunit. Dedicated to Professor Jonathan Williams, an inspirational and humble pioneer, a colleague and mentor in chemistry

Brain-derived neurotrophic factor modulates fast synaptic inhibition by regulating GABA(A) receptor phosphorylation, activity, and cell-surface stability

The efficacy of GABAergic synaptic inhibition is a principal factor in controlling neuronal activity. We demonstrate here that brain-derived neurotrophic factor modulates the activity of GABA(A) receptors, the main sites of fast synaptic inhibition in the brain, within minutes of application. Temporally, this comprised an early enhancement in the miniature IPSC amplitude, followed by a prolonged depression. This modulation was concurrent with enhanced PKC-mediated phosphorylation, followed by protein phosphatase 2A (PP2A)-mediated dephosphorylation of the GABA(A) receptor. Mechanistically, these events were facilitated by differential recruitment of PKC, receptor for activated C-kinase, and PP2A to GABA(A) receptors, depending on the phosphorylation state of the receptor beta(3)-subunit. Thus, transient formation of GABA(A) receptor signaling complexes has the potential to provide a basis for acute changes in receptor function underlying GABAergic synaptic plasticity

A framework for the testing and validation of simulated environments in experimentation and training

This is the final version. Available on open access from Frontiers Media via the DOI in this recordNew computer technologies, like virtual reality (VR), have created opportunities to study human behaviour and train skills in novel ways. VR holds significant promise for maximising the efficiency and effectiveness of skill learning in a variety of settings (e.g., sport, medicine, safety-critical industries) through immersive learning and augmentation of existing training methods. In many cases the adoption of VR for training has, however, preceded rigorous testing and validation of the simulation tool. In order for VR to be implemented successfully for both training and psychological experimentation it is necessary to first establish whether the simulation captures fundamental features of the real task and environment, and elicits realistic behaviours. Unfortunately evaluation of VR environments too often confuses presentation and function, and relies on superficial visual features that are not the key determinants of successful training outcomes. Therefore evidence-based methods of establishing the fidelity and validity of VR environments are required. To this end, we outline a taxonomy of the subtypes of fidelity and validity, and propose a variety of practical methods for testing and validating VR training simulations. Ultimately, a successful VR environment is one that enables transfer of learning to the real-world. We propose that key elements of psychological, affective and ergonomic fidelity, are the real determinants of successful transfer. By adopting an evidence-based approach to VR simulation design and testing it is possible to develop valid environments that allow the potential of VR training to be maximised.Royal Academy of Engineering (RAE)Innovate U

Automated data analysis to rapidly derive and communicate ecological insights from satellite-tag data: A case study of reintroduced red kites

Analysis of satellite-telemetry data mostly occurs long after it has been collected, due to the time and effort needed to collate and interpret such material. Such delayed reporting does reduce the usefulness of such data for nature conservation when timely information about animal movements is required. To counter this problem we present a novel approach which combines automated analysis of satellite-telemetry data with rapid communication of insights derived from such data. A relatively simple algorithm (comprising speed of movement and turning angle calculated from fixes), allowed instantaneous detection of excursions away from settlement areas and automated calculation of home ranges on the remaining data Automating the detection of both excursions and home range calculations enabled us to disseminate ecological insights from satellite-tag data instantaneously through a dedicated web portal to inform conservationists and wider audiences. We recommend automated analysis, interpretation and communication of satellite tag and other ecological data to advance nature conservation research and practice

Constitutive endocytosis of GABA(A) receptors by an association with the adaptin AP2 complex modulates inhibitory synaptic currents in hippocampal neurons

Type A GABA receptors (GABA(A)) mediate the majority of fast synaptic inhibition in the brain and are believed to be predominantly composed of alpha, beta, and gamma subunits. Although changes in cell surface GABA(A) receptor number have been postulated to be of importance in modulating inhibitory synaptic transmission, little is currently known on the mechanism used by neurons to modify surface receptor levels at inhibitory synapses. To address this issue, we have studied the cell surface expression and maintenance of GABA(A) receptors. Here we show that constitutive internalization of GABA(A) receptors in hippocampal neurons and recombinant receptors expressed in A293 cells is mediated by clathrin- dependent endocytosis. Furthermore, we identify an interaction between the GABA(A) receptor beta and gamma subunits with the adaptin complex AP2, which is critical for the recruitment of integral membrane proteins into clathrin-coated pits. GABA(A) receptors also colocalize with AP2 in cultured hippocampal neurons. Finally, blocking clathrin-dependant endocytosis with a peptide that disrupts the association between amphiphysin and dynamin causes a large sustained increase in the amplitude of miniature IPSCs in cultured hippocampal neurons. These results suggest that GABA(A) receptors cycle between the synaptic membrane and intracellular sites, and their association with AP2 followed by recruitment into clathrin- coated pits represents an important mechanism in the postsynaptic modulation of inhibitory synaptic transmission

A magic leap in tourism: Intended and realized experience of head-mounted augmented reality in a museum context

This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record Data Availability Statement: The data that support the findings of this study are openly available from the OSF at https://osf.io/BT3UV/.Augmented reality (AR) is an emergent technology in tourism. However, research concerning the AR user experience is relatively scarce and seldom addresses the intentions of designers. Accordingly, we sought to: (a) explore the design intentions underlying a multi-user, purpose-built AR experience; (b) assess the extent to which users’ realized experience aligned with the designers’ intended experience; and (c) examine the relationships between users’ internal states and their associated behavior, in alignment with a Stimulus-Organism-Response framework. In Study 1, designers (n = 5) took part in a focus group and completed a design intentions survey. In Study 2, users (n = 48) tested the AR experience, and a range of subjective (e.g., affective responses) and objective (i.e., visual attention) data were recorded. Findings indicated designer–user disparities primarily at the organism and response levels. Additionally, users’ affective responses to the AR experience were strongly associated with visitor engagement.Innovate U

Identification of residues within GABA(A) receptor subunits that mediate specific assembly with receptor β subunits

GABA(A) receptors can be constructed from a range of differing subunit isoforms: alpha, beta, gamma, delta, and epsilon. Expression studies have revealed that production of GABA-gated channels is achieved after coexpression of alpha and beta subunits. The expression of a gamma subunit isoform is essential to confer benzodiazepine sensitivity on the expressed receptor. However, how the specificity of subunit interactions is controlled during receptor assembly remains unknown. Here we demonstrate that residues 58-67 within alpha subunit isoforms are important in the assembly of receptors comprised of alphabeta and alphabetagamma subunits. Deletion of these residues from the alpha1 or alpha6 subunits results in retention of either alpha subunit isoform in the endoplasmic reticulum on coexpression with the beta3, or beta3 and gamma2 subunits. Immunoprecipitation revealed that residues 58-67 mediated oligomerization of the alpha1 and beta3 subunits, but were without affect on the production of alpha/gamma complexes. Within this domain, glutamine 67 was of central importance in mediating the production of functional alpha1beta3 receptors. Mutation of this residue resulted in a drastic decrease in the cell surface expression of alpha1beta3 receptors and the resulting expression of beta3 homomers. Sucrose density gradient centrifugation revealed that this residue was important for the production of a 9S alpha1beta3 complex representing functional GABA(A) receptors. Therefore, our studies detail residues that specify GABA(A) receptor alphabeta subunit interactions. This domain, which is conserved in all alpha subunit isoforms, will therefore play a critical role in the assembly of GABA(A) receptors composed of alphabeta and alphabetagamma subunits

Effects of Gabra2 Point Mutations on Alcohol Intake: Increased Binge-Like and Blunted Chronic Drinking by Mice

BACKGROUND: Alcohol use disorders are associated with single-nucleotide polymorphisms in GABRA2, the gene encoding the GABAA receptor α2-subunit in humans. Deficient GABAergic functioning is linked to impulse control disorders, intermittent explosive disorder, and to drug abuse and dependence, yet it remains unclear whether α2-containing GABAA receptor sensitivity to endogenous ligands is involved in excessive alcohol drinking. METHODS: Male wild-type (Wt) C57BL/6J and point-mutated mice rendered insensitive to GABAergic modulation by benzodiazepines (BZD; H101R), allopregnanolone (ALLO) or tetrahydrodeoxycorticosterone (THDOC; Q241M), or high concentrations of ethanol (EtOH) (S270H/L277A) at α2-containing GABAA receptors were assessed for their binge-like, moderate, or escalated chronic drinking using drinking in the dark, continuous access (CA) and intermittent access (IA) to alcohol protocols, respectively. Social approach by mutant and Wt mice in forced alcohol abstinence was compared to approach by EtOH-naïve controls. Social deficits in forced abstinence were treated with allopregnanolone (0, 3.0, 10.0 mg/kg, intraperitoneal [i.p.]) or midazolam (0, 0.56, 1.0 mg/kg, i.p.). RESULTS: Mice with BZD-insensitive α2-containing GABAA receptors (H101R) escalated their binge-like drinking. Mutants harboring the Q241M point substitution in Gabra2 showed blunted chronic intake in the CA and IA protocols. S270H/L277A mutants consumed excessive amounts of alcohol but, unlike wild-types, they did not show forced abstinence-induced social deficits. CONCLUSIONS: These findings suggest a role for: (i) H101 in species-typical binge-like drinking, (ii) Q241 in escalated chronic drinking, and (iii) S270 and/or L277 in the development of forced abstinence-associated social deficits. Clinical findings report reduced BZD-binding sites in the cortex of dependent patients; the present findings suggest a specific role for BZD-sensitive α2-containing receptors. In addition, amino acid residue 241 in Gabra2 is necessary for positive modulation and activation of GABAA receptors by ALLO and THDOC; we postulate that neurosteroid action on α2-containing receptor may be necessary for escalated chronic EtOH intake