Validation of an animal model of cognitive dysfunction associated with schizophrenia. Development and validation of the novel object recognition task using behavioural manipulations and psychotomimetic dosing regimens to induce cognitive deficits of relevance to schizophrenia in hooded-Lister rats.

Phencyclidine (PCP) is a non-competitive NMDA receptor antagonist that has been shown to induce schizophrenia-like psychotic symptoms that are clinically indistinguishable from schizophrenia in patients. When administered to rodents, PCP produces an array of behaviours that are characteristic of schizophrenia. Schizophrenia is associated with continual and treatment resistant cognitive deficits which are now recognised as a core feature of the disease. The aim of the studies reported in chapter 3 were to establish a set of objects with equal preference in the NOR (novel object recognition) test. Furthermore, the inter-trial-interval (ITI) of the NOR test was investigated in an attempt to elucidate the effects of time and location of the rats during the ITI on the cognitive impairments following sub-chronic PCP treatment. The experiments in chapter 4 were designed to compare the performance of male and female rats in the NOR test following treatment with acute d-amphetamine (d-amph), PCP and sub-chronic PCP treatment. In chapter 5, validation of the cognitive deficits induced by sub-chronic PCP treatment was assessed using carefully selected pharmacological agents. The aim of the studies in chapter 6 was to determine the effects of isolation rearing on cognitive performance in the NOR test following increasing ITIs. Additionally, the sensitivity of isolation reared rats compared to social controls following acute administration of PCP and d-amph was assessed using the NOR test. Studies in chapter 8 utilised the 16-holeboard maze to determine the effects of acute treatment with d-amphetamine, PCP and scopolamine on working memory in the rat. NOR is a visual learning and memory test that measures recognition memory which is impaired in patients with schizophrenia. Studies presented in this thesis demonstrate the importance of careful pilot studies when selecting objects for use in the NOR test. Initial studies in sub-chronic PCP (2 mg/kg for 7 days followed by 7 days drug free) treated female hooded-Lister rats revealed a preference of the rats for the wooden cone object; subsequently this object was eliminated from further NOR experiments. Sub-chronic PCP treated rats were found to be highly susceptible to the disruptive influence of distraction during the short 1 min inter-trial-interval (ITI) in the NOR test. These results are consistent with clinical findings of the effects of distraction on cognition in schizophrenia patients. Following the initial validation experiments, a 1 min ITI in the home cage was selected for all subsequent NOR studies. Further experiments provided evidence to confirm that information presented in the acquisition trial is encoded but not retained in the retention trial of the NOR test by IV PCP-treated rats. Male rats were less sensitive to the recognition memory deficits induced by acute treatment with PCP and d-amphetamine compared with females. Following sub-chronic PCP treatment, both males and females showed object recognition deficits, however, the impairments were more robust in female rats. Female rats were therefore selected for all subsequent experiments. Pharmacological validation was carried out using carefully selected agents which were assessed for their ability to restore the sub-chronic PCP induced cognitive deficit in the object recognition test. It was found that the classical antipsychotic agents haloperidol and fluphenazine, the benzodiazepine anxiolytic chlordiazepoxide and the SSRI antidepressant fluoxetine were ineffective. Further studies showed that the atypical antipsychotic agents, clozapine and risperidone, the analeptic agent modafinil, the nAChR full agonist nicotine, and full agonist and positive allosteric modulator of the ¿7 nAChR (PNU-282987 and PNU120596 respectively) reversed the recognition memory deficit induced by sub-chronic PCP treatment in the NOR test. Isolation rearing of rats at weaning is an environmental stressor that has relevance for modelling the symptomatology and pathology of schizophrenia. Isolates had a significantly increased locomotor activity (LMA) response to a novel environment and enhanced sensitivity to time delay-induced recognition memory deficits, compared with their socially reared counterparts. Isolates were less sensitive to an acute PCP-induced recognition memory deficit but more sensitive to an acute d-amphetamine induced recognition memory deficit in the NOR test compared to social controls. Preliminary results from the 16-holeboard maze experiments reveal that acute administration of the mAChR antagonist scopolamine, d-amphetamine, PCP and sub-chronic PCP treatment reduced working memory scores compared to vehicle treated controls. Taken together, these findings suggest that sub-chronic treatment with PCP induces cognitive deficits in behavioural tests of relevance to cognition associated with schizophrenia. This may allow the detection of novel pharmacotherapies to alleviate these cognitive deficits and exploration of the nature of cognitive disturbances in these patients

GPS precise point positioning for UAV photogrammetry

The use of Global Positioning System (GPS) precise point positioning (PPP) on a fixed‐wing unmanned aerial vehicle (UAV) is demonstrated for photogrammetric mapping at accuracies of centimetres in planimetry and about a decimetre in height, from flights of 25 to 30 minutes in duration. The GPS PPP estimated camera station positions are used to constrain estimates of image positions in the photogrammetric bundle block adjustment, as with relative GPS positioning. GPS PPP alleviates all spatial operating constraints associated with the installation and the use of ground control points, a local ground GPS reference station or the need to operate within the bounds of a permanent GPS reference station network. This simplifies operational logistics and enables large‐scale photogrammetric mapping from UAVs in even the most remote and challenging geographic locations

Activation of α7 nicotinic receptors improves phencyclidine-induced deficits in cognitive tasks in rats: Implications for therapy of cognitive dysfunction in schizophrenia

YesRationale: Nicotinic α7 acetylcholine receptors (nAChRs) have been highlighted as a target for cognitive enhancement in schizophrenia. Aim: To investigate whether the deficits induced by sub-chronic phencyclidine (PCP) in reversal learning and novel object recognition could be attenuated by the selective α7 nAChR full agonist, PNU-282987. Methods: Adult female hooded-Lister rats received sub-chronic PCP (2 mg/kg) or vehicle i.p. twice daily for seven days, followed by 7-days washout. In cohort 1, PCP-treated rats then received PNU-282987 (5, 10, 20 mg/kg; s.c.) or vehicle and were tested in the reversal learning task. In cohort 2, PCP-treated rats received PNU-282987 (10 mg/kg; s.c.) or saline for 15 days and were tested in the novel object recognition test on day 1 and on day 15, to test for tolerance. Results: Sub-chronic PCP produced significant deficits in both cognitive tasks (P<0.01-0.001). PNU-282987 attenuated the PCP-induced deficits in reversal learning at 10 mg/kg (P<0.01) and 20 mg/kg (P<0.001), and in novel object recognition at 10 mg/kg on day 1 (P<0.01) and on day 15 (P<0.001). Conclusions: These data show that PNU-282987 has efficacy to reverse PCP-induced deficits in two paradigms of relevance to schizophrenia. Results further suggest that 15 day daily dosing of PNU-282987 (10 mg/kg s.c.) does not cause tolerance in rat. This study suggests that activation of α7 nAChRs, may represent a suitable strategy for improving cognitive deficits of relevance to schizophrenia.SL McLean was supported by a joint University of Bradford–GSK postgraduate studentship

PNU-120596, a positive allosteric modulator of α7 nicotinic acetylcholine receptors, reverses a sub-chronic phencyclidineinduced cognitive deficit in the attentional set-shifting task in female rats

yThe α7 nicotinic acetylcholine receptors (nAChRs) have been highlighted as a target for cognitive enhancement in schizophrenia. Adult female hooded Lister rats received sub-chronic phencyclidine (PCP) (2mg/kg) or vehicle i.p. twice daily for 7 days, followed by 7 days’ washout. PCP-treated rats then received PNU-120596 (10mg/kg; s.c.) or saline and were tested in the attentional set-shifting task. Sub-chronic PCP produced a significant cognitive deficit in the extra-dimensional shift (EDS) phase of the task (p < 0.001, compared with vehicle). PNU-120596 significantly improved performance of PCP-treated rats in the EDS phase of the attentional set-shifting task (p < 0.001). In conclusion, these data demonstrate that PNU-120596 improves cognitive dysfunction in our animal model of cognitive dysfunction in schizophrenia, most likely via modulation of α7 nACh receptors.This work was partially funded by Johnson & Johnson Pharmaceutical Research and Development

Functionalized Double Strain-Promoted Stapled Peptides for Inhibiting the p53-MDM2 Interaction.

The Sondheimer dialkyne reagent has previously been employed in strain-promoted double-click cycloadditions with bis-azide peptides to generate stapled peptide inhibitors of protein-protein interactions. The substituted variants of the Sondheimer dialkyne can be used to generate functionalized stapled peptide inhibitors with improved biological properties; however, this remains a relatively underdeveloped field. Herein, we report the synthesis of new substituted variants of Sondheimer dialkyne and their application in the stapling of p53-based diazido peptides to generate potent stapled peptide-based inhibitors of the oncogenic p53-MDM2 interaction. The functionalized stapled peptide formed from a meta-fluoro-substituted Sondheimer dialkyne was found to be the most potent inhibitor. Furthermore, through experimental studies and density functional theory calculations, we investigated the impact of the substituent on the strain-promoted double-click reactivity of Sondheimer dialkyne

Oscillatory deficits in the sub-chronic PCP rat model for schizophrenia are reversed by mGlu5 receptor-positive allosteric modulators VU0409551 and VU0360172

The cognitive deficits of schizophrenia are linked to imbalanced excitatory and inhibitory signalling in the prefrontal cortex (PFC), disrupting gamma oscillations. We previously demonstrated that two mGlu5 receptor-positive allosteric modulators (PAMs), VU0409551 and VU0360172, restore cognitive deficits in the sub-chronic PCP (scPCP) rodent model for schizophrenia via distinct changes in PFC intracellular signalling molecules. Here, we have assessed ex vivo gamma oscillatory activity in PFC slices from scPCP rats and investigated the effects of VU0409551 and VU0360172 upon oscillatory power. mGlu5 receptor, protein kinase C (PKC), and phospholipase C (PLC) inhibition were also used to examine ‘modulation bias’ in PAM activity. The amplitude and area power of gamma oscillations were significantly diminished in the scPCP model. Slice incubation with either VU0409551 or VU0360172 rescued scPCP-induced oscillatory deficits in a concentration-dependent manner. MTEP blocked the PAM-induced restoration of oscillatory power, confirming the requirement of mGlu5 receptor modulation. Whilst PLC inhibition prevented the power increase mediated by both PAMs, PKC inhibition diminished the effects of VU0360172 but not VU0409551. This aligns with previous reports that VU0409551 exhibits preferential activation of the phosphatidylinositol-3-kinase (PI3K) signalling pathway over the PKC cascade. Restoration of the excitatory/inhibitory signalling balance and gamma oscillations may therefore underlie the mGluR5 PAM-mediated correction of scPCP-induced cognitive deficits

Trust in financial services: Retrospect and prospect

Fostering and maintaining high levels of trust in the financial services sector is seen as crucial because of the characteristics of many financial service and in order to promote consumer engagement in the sector. In this article, we report evidence from a body of work and other commentary to provide an insight into trends in consumer trust in the sector as a whole, in comparison with other organisations and how different types of financial services provider have performed relative to each other. We show that the financial services sector as a whole is trusted more than some comparator institutions, and that aggregate levels of trust in the sector have fluctuated a relatively small amount subsequent to the financial crisis. However, important differences between provider types are apparent and these differences have become more profound in the recent past. We provide suggestions as to how trust in the sector may be improved and provider an analysis of current initiatives to improve trust levels in the sector in general and in banking in particular

Nicotinic α7 and α4β2 agonists enhance the formation and retrieval of recognition memory: potential mechanisms for cognitive performance enhancement in neurological and psychiatric disorders

YesCholinergic dysfunction has been shown to be central to the pathophysiology of Alzheimer’s disease and has also been postulated to contribute to cognitive dysfunction observed in various psychiatric disorders, including schizophrenia. Deficits are found across a number of cognitive domains and in spite of several attempts to develop new therapies, these remain an unmet clinical need. In the current study we investigated the efficacy of donepezil, risperidone and selective nicotinic α7 and α4β2 receptor agonists to reverse a delay-induced deficit in recognition memory. Adult female Hooded Lister rats received drug treatments and were tested in the novel object recognition (NOR) task following a 6 h inter-trial interval (ITI). In all treatment groups, there was no preference for the left or right identical objects in the acquisition trial. Risperidone failed to enhance recognition memory in this paradigm whereas donepezil was effective such that rats discriminated between the novel and familiar object in the retention trial following a 6 h ITI. Although a narrow dose range of PNU-282987 and RJR- 2403 was tested, only one dose of each increased recognition memory, the highest dose of PNU-282987 (10 mg/kg) and the lowest dose of RJR-2403 (0.1 mg/kg), indicative of enhanced cognitive performance. Interestingly, these compounds were also efficacious when administered either before the acquisition or the retention trial of the task, suggesting an important role for nicotinic receptor subtypes in the formation and retrieval of recognition memory.This work was conducted at the University of Bradford and was funded by b-neuro. However all our recent studies mentioned in the discussion section have been conducted at the University of Manchester (UoM), and funded by b-neuro, Autifony, Innovate UK (formerly TSB) and Uo