This thesis aimed to examine the roles of growth differentiation factor 5 (GDF5), a secreted member of the TGF-β superfamily of ligands with a well characterised role in limb morphogenesis, in the developing hippocampus and sympathetic nervous system. Previous studies have demonstrated that GDF5 promotes the growth and elaboration of dendrites from developing mouse hippocampal neurons in vitro and in vivo. As a first step to investigating whether GDF5 plays additional roles in the development of the mouse hippocampus, brains of P10 and adult Gdf5+/+, Gdf5+/bp and Gdf5bp/bp mice were analysed by anatomical MRI. The gross morphology and total volume of hippocampi were not significantly different between the three genotypes at either age, making it unlikely that GDF5 plays a significant role in modulating other aspects of hippocampal development in addition to promoting the growth and elaboration of dendrites. For this reason, no further time was spent on investigating whether GDF5 plays novel roles in regulating hippocampal development. Developing sympathetic neurons of the mouse superior cervical ganglion (SCG) require nerve growth factor (NGF) to promote their survival and target field innervation in vivo. Data in this thesis has revealed that GDF5 modulates NGF promoted survival and enhances NGF promoted process outgrowth in cultures of P0 SCG neurons. In addition, GDF5 promotes process outgrowth and branching from cultured perinatal SCG neurons in the absence of NGF. P10 Gdf5bp/bp mice, that lack functional GDF5 expression, display a marked deficit in sympathetic innervation of the iris, but not the submandibular gland, compared to P10 Gdf5+/+ mice. Whole-mount analysis of sympathetic innervation in P10 Gdf5bp/bp and Gdf5+/+ mice has revealed that GDF5 is required for correct innervation of the trachea and heart, but not the pineal gland. Further in vitro and in vivo investigations have suggested that the neurotrophic effects of GDF5 on developing SCG neurons are mediated by a receptor complex that includes the type 1 receptor, BMPR1A. These findings highlight a role for GDF5 in promoting the sympathetic innervation of selective target fields in vivo.

Background: Delusions are common in psychosis, defined as fixed, false beliefs. Some studies, however, have found that they may be less fixed than previously thought, possibly changing in response to talking about them. Relatives of people with psychosis or clinical staff often ask how to respond to them when they talk about their delusions, but no available advice appears to be evidence based. Aims: To review evidence on everyday communication about delusions and find out how people with delusions talk about them with others, taking three perspectives (patients, their nominated relatives and clinicians) and to construct a model for communication in relation to the delusion according to each party independently. Methods: 36 patients were engaged in semi-structured interviews about their mental state generally (Comprehensive Psychopathological Rating Scale) and their delusion (Maudsley Assessment of Delusions Schedule). Each patient was asked to nominate a relative and a professional to whom s/he spoke about the delusion. Relatives and staff were interviewed by different researchers. Results: Most patients reported speaking to others about their delusion and nominated an informant. Most felt emotionally disturbed by their delusions, but, against prediction, this did not affect nomination; nor did their delusion content. There was good agreement between the three parties on occurrence of such communication. Some patients had self-harmed; only some relatives or staff concurred with them on attributing this to the delusion. A testable hypothesis was generated that the intrusiveness of delusions resulted in personal change for the patient and sense of changed relationship and detachment for the others. Conclusions: No previous study has investigated communication about delusions between three parties. It was striking that so few relatives were engaged. If patients, their families and clinicians could improve mutual understanding of delusions, the safety of the patient and others as well as treatment might be improved.

Tumour necrosis factor (TNF) is an extensively well characterised proinflammatory cytokine. It is expressed as a type two membrane glycoprotein that is active both as a membrane-integrated ligand and as a soluble ligand following proteolytic release of the ectodomain from the cell membrane. TNF signals via two receptors, TNFR1 and TNFR2. In the immune system, it has been shown that these receptors can function as ligands for membrane-integrated TNF and initiate TNF reverse signalling. I was a member of a team that discovered, characterised and evaluated the physiological significance of TNF reverse signalling in the nervous system. We showed that TNFR1 is expressed in tissues innervated by sympathetic neurons and that this initiates TNF reverse signalling in postnatal sympathetic axons, which in turn enhances their growth and branching locally. Using a tissue whole mount method to visualize sympathetic fibres, I found that the innervation of multiple tissues that receive their innervation exclusively or predominantly from the paravertebral sympathetic chain is defective both in mice lacking TNF and mice lacking TNFR1. Sympathetic fibres reach these tissues in these mice but fail to grow and branch extensively in these tissues. In contrast, tissues that receive their sympathetic innervation predominantly from prevertebral ganglia are either unaffected, in mice lacking TNF and TNFR1, or hyperinnervated. Using live calcium imaging, pharmacological blockers of calcium channels and shRNA gene knockdown, I obtained evidence that T-type calcium channels are required for the effects of TNF reverse signalling on axon growth. I also showed that TNF reverse signalling enhances the growth of sensory axons, during an earlier stage in development than sympathetic neurons. This work establishes that TNF reverse signalling is widely involved in regulating axon growth in the developing peripheral nervous system.

Amyotrophic lateral sclerosis (ALS) is an aggressive neurodegenerative disease characterised by the loss of upper and lower motor neurons, resulting in progressive paralysis, muscular atrophy and eventual death, on average, within 2-5 years post diagnosis. In ∼5% of patients with familial ALS (fALS), causative mutations occur within the gene encoding the RNA-binding protein, Fused in Sarcoma (FUS). Normally, FUS is predominantly localised to the nucleus and has several known roles in transcription, splicing and mRNA transport. Yet, in ALS patients with mutant forms of FUS, the protein becomes dramatically mislocalised to the cytoplasm and abnormal proteinaceous inclusions of FUS in the cytoplasm are observed post-mortem. Several questions remain: How do large pathological inclusions of FUS form? Is pathology induced via a gain or loss of protein function? Can aggregation in the cytoplasm of this normally nuclear protein be sufficient to produce toxicity? This thesis provides detailed characterisation of a novel pathway through which FUS may aggregate following its mislocalisation to the cytoplasm. This pathway is distinct from recruitment into stressinduced stress granules and can lead to the formation of large RNA-based FUS aggregates in a concentration-dependent manner. It was demonstrated that reduced protein-RNA interaction through transcriptional inhibition resulted in the dissolution and reassembly of these FUS aggregates into higher order RNA-free structures, reminiscent of inclusions seen in ALS-FUS patients. We also show in vivo that an initial insult of FUS aggregation in the cytoplasm is sufficient to elicit ALS-like pathology. In addition, how loss of FUS from the nucleus could affect the nuclear architecture was investigated, highlighting an important role for FUS in the maintenance of a protective subnuclear body, the paraspeckle, the disruption of which may contribute to the pathogenesis of FUSopathies. As such, this thesis identifies several novel mechanisms involved in the development and progression of FUSopathy, which may be useful for future therapeutic strategies targeting ALS caused by FUS mutation.

22q11.2 Deletion Syndrome (22q11.2DS) is one of the strongest known risk factors for schizophrenia. The syndrome provides a rare opportunity to prospectively examine development that precedes schizophrenia. 22q11.2DS is also associated with a range of psychiatric disorders and cognitive deficits. The overall aim of this thesis is to examine the neuropsychiatric phenotype of 22q11.2DS through a developmental lens. This thesis uses data from Cardiff University’s ECHO (Experiences of CHildren with cOpy number variants) study which includes a longitudinal cohort of children with 22q11.2DS. Development in 22q11.2DS is contrasted to that of the unaffected siblings of children with 22q11.2DS. First psychopathology is examined longitudinally across early adolescence in 22q11.2DS. Children with 22q11.2DS have a significant burden of psychopathology across early adolescence, including attention-deficit/hyperactivity disorder (ADHD), anxiety disorders and autism spectrum disorder (ASD). There is a striking increase in the prevalence of psychotic experiences and a decrease in ADHD prevalence. The ASD phenotype is examined further using a diagnostic interview of developmental history. ASD and subthreshold phenomenology is found to be highly prevalent in the early development of children with 22q11.2DS. Next cognitive development in 22q11.2DS is considered and contrasted to that in unaffected siblings. Cognitive deficits across a range of domains are present in 22q11.2DS. Cognitive development in 22q11.2DS is found to be similar to that reported in children who later develop idiopathic schizophrenia. This is followed by an exploration of the relations between psychopathology and cognitive development in 22q11.2DS. Cognitive development is found to predict the emergence of psychotic experiences and the persistence of ADHD in 22q11.2DS. This thesis extends what is known about the development of the neuropsychiatric phenotype in 22q11.2DS. Furthermore, findings give an insight into the developmental pathways associated with a high risk of developing schizophrenia.

Individuals with Major Mental Illness (such as schizophrenia and bipolar disorder) experience increased rates of physical health comorbidity compared to the general population. They also experience inequalities in access to certain aspects of healthcare. This ultimately leads to premature mortality. Studies detailing patterns of physical health comorbidity are limited by their definitions of comorbidity, single disease approach to comorbidity and by the study of heterogeneous groups. To date the investigation of possible sources of healthcare inequalities experienced by individuals with Major Mental Illness (MMI) is relatively limited. Moreover studies detailing the extent of premature mortality experienced by individuals with MMI vary both in terms of the measure of premature mortality reported and age of the cohort investigated, limiting their generalisability to the wider population. Therefore local and national data can be used to describe patterns of physical health comorbidity, investigate possible reasons for health inequalities and describe mortality rates. These findings will extend existing work in this area.

No description available.

Complex regional pain syndrome (CRPS) is a painful, debilitating condition that is poorly understood. The syndrome is characterised by pain, motor disturbances and abnormalities in trophic, sudomotor, vascular temperature and sensation. The underlying mechanisms are unknown. Clinical observations have identified a novel phenomenon whereby patients pay little attention to, and fail to care for, their painful affected limb. The literature describes this phenomenon in terms of neglect-like symptoms similar to neurological neglect as described in stroke literature. However, this does not seem to fully fit with or explain the nature of clinical observations. Therefore the aim of the qualitative first study was to more fully describe the phenomenon through an investigation of the patient experience and words used to describe those experiences. Six themes emerged from the data and were as follows: hostile feelings; spectrum of disassociation; disparity between what is apparent and what is felt; distorted mental image of affected parts; awareness of limb position and conscious attention. From these findings a theory emerged which serves to further our understanding of body perception disturbance in CRPS. Based on these findings, the second study aimed to quantify a feature of body perception disturbance by measuring limb position accuracy of those with CRPS compared to Healthy Controls (HC) and those with Rheumatological Pain (RP). The CRPS group were significantly less accurate in positioning of both the affected and unaffected upper limbs (median=9°, Interquartile rang e (IQR), 5.7°-13.3°) compared to both HC (6.5°, IQR, 4°-10.7°) and RP groups (7.7°, IQR, 5 °-11.7°). In the CRPS group position accuracy of the affected limb significantly improved with vision (8.3° in view, 10.7° not in view). Pain intensity was significantly greater in the CRPS (6.5, IQR, 5.4-7.7) than the RP group (4.6, IQR, 3.6-5.7). Based on the findings of this research programme, a definition of body perception disturbance in CRPS is presented. Furthermore, a disrupted body schema model is proposed as an explanation of the central mechanisms responsible for body perception disturbance in CRPS.

Insomnia is a common disturbance of sleep which can be treated effectively with cognitive behavioural therapy; a multicomponent ‘package’ of cognitive and behavioural strategies. Sleep restriction therapy is thought to be one of the most potent behavioural components of cognitive behavioural therapy. Subjective measures of sleep and daytime functioning improve not only with cognitive behavioural therapy, but also during and following sleep restriction therapy. However, it is unknown when these changes occur or if there are associated objective changes. This thesis addresses these issues, and presents: 1. a review of the literature of therapy and original research; 2. evaluates the nature and timing of changes in self-reported daytime functioning during therapy; 3. profiles potential objective changes (in measurements of sleep, plasma and salivary cortisol concentrations & temperature); and 4. compares patients with different subtypes of insomnia and healthy good sleeping controls for possible differences within the brain that might serve as future targets for treatment. The final general discussion ties together the results of these data-based chapters. The following section aims to provide a brief summary of the overall thesis. This Ph.D. was undertaken as Cotutelle Agreement between the Universities of Glasgow, United Kingdom and Sydney, Australia. Specific chapters relate to the data collection performed at these two sites. Consequently this thesis has been split into specific chapters from where the data were obtained. Chapters four and five consist of data acquired from Glasgow, United Kingdom whilst in chapters six and seven the data were acquired in Sydney, Australia.

Have you ever entered a room and wondered ‘What am I supposed to do here?’ or have you ever forgotten to turn off the oven, hang your clothes to dry or make a phone call. These examples illustrate the relevance of ‘prospective memory’ or ‘delayed intentions’ in our daily life activities. Prospective memory is the ability to remember to do something after a delay. This thesis addresses three questions relevant to understand maintenance and execution of intentions: Is attention required to retrieve delayed intentions? What does monitoring mean in the context of prospective memory? Is prospective memory a discrete memory system or it is based on already known attentional and memory mechanisms? To answer these questions, we used electroencephalography (EEG), in (traditional) non-movement and free-movement experimental paradigms. We explored the neural substrate of prospective memory across its different stages: (1) holding intentions during a delay, (2) detecting the right context to perform the delayed intention, and (3) retrieving the content of the intention (the action to be performed). Two types of prospective memory tasks were used: Event-based prospective memory (performing a delayed intention in response to an external cue) and time-based prospective memory (performing the intention at a particular time). Results indicate that: prospective memory always requires attention, at least in experimental contexts; monitoring involves different mechanisms depending on the particular features of the prospective memory task and; prospective memory is not a discrete memory system, but relies on well-established mechanisms for attention and executive control.