Quality of radiology training and role of Royal Australian and New Zealand College of Radiology in supporting radiology trainees in NSW: Results of the first radiology trainee survey.

INTRODUCTION: The Royal Australian and New Zealand College radiology training programme is a 5-year programme with a vast curriculum including reporting and research requirements. Undertaking training can be stressful for trainees who must balance their educational needs and work responsibilities. We undertook the first independent survey of New South Wales (NSW) radiology trainees to evaluate their perceptions about the quality of their training. METHODS: Focus groups with trainees from multiple NSW training sites were conducted to construct a survey which was then distributed to all NSW Radiology trainees (n = 118). Data from the survey were analysed, and factors correlating to the overall satisfaction with the programme were explored using Spearman's correlation. RESULTS: Survey response rate was 70.3%. Eighty-nine per cent of trainees were satisfied with their career choice, and 73% were satisfied with the training programme. Majority felt they had a good exposure to cases, modalities and access to resources to complete their training. Trainee satisfaction significantly correlated with a supportive work environment (rs  = 0.83, P < 0.0001), which involved supportive consultants (rs  = 0.75, P < 0.0001), good peer support (rs  = 0.60, P < 0.0001) and their training site respecting work/life balance (rs  = 0.62, P < 0.0001). As trainees progressed through the training programme, they became less satisfied, with trainees in years 3 and above being the most dissatisfied. CONCLUSION: NSW radiology trainees are generally satisfied with their training programme and career choices. Trainee satisfaction correlated most strongly with supportive work environment, good consultant support, peer relationships and good work/life balance; satisfaction decreased for senior trainees.

Cris never left you wondering about where you stood! His motto was: Just do it!

In this commentary, we reflect on our experiences being PhD students of Prof. Cris dos Remedios in the Muscle Research Unit at The University of Sydney at the turn of the new millennium. Cris was/is an example of a fine scientist and a great academic mentor for us and so many others (scientists, academics, surgeons, medical doctors and health professionals) who carry the legacy and traditions of Cris dos Remedios into the future.

Visualizing the in vitro assembly of tropomyosin/actin filaments using TIRF microscopy.

Tropomyosins are elongated alpha-helical proteins that form co-polymers with most actin filaments within a cell and play important roles in the structural and functional diversification of the actin cytoskeleton. How the assembly of tropomyosins along an actin filament is regulated and the kinetics of tropomyosin association with an actin filament is yet to be fully determined. A recent series of publications have used total internal reflection fluorescence (TIRF) microscopy in combination with advanced surface and protein chemistry to visualise the molecular assembly of actin/tropomyosin filaments in vitro. Here, we review the use of the in vitro TIRF assay in the determination of kinetic data on tropomyosin filament assembly. This sophisticated approach has enabled generation of real-time single-molecule data to fill the gap between in vitro bulk assays and in vivo assays of tropomyosin function. The in vitro TIRF assays provide a new foundation for future studies involving multiple actin-binding proteins that will more accurately reflect the physiological protein-protein interactions in cells.

High-Content Imaging of Unbiased Chemical Perturbations Reveals that the Phenotypic Plasticity of the Actin Cytoskeleton Is Constrained.

Although F-actin has a large number of binding partners and regulators, the number of phenotypic states available to the actin cytoskeleton is unknown. Here, we quantified 74 features defining filamentous actin (F-actin) and cellular morphology in >25 million cells after treatment with a library of 114,400 structurally diverse compounds. After reducing the dimensionality of these data, only ∼25 recurrent F-actin phenotypes emerged, each defined by distinct quantitative features that could be machine learned. We identified 2,003 unknown compounds as inducers of actin-related phenotypes, including two that directly bind the focal adhesion protein, talin. Moreover, we observed that compounds with distinct molecular mechanisms could induce equivalent phenotypes and that initially divergent cellular responses could converge over time. These findings suggest a conceptual parallel between the actin cytoskeleton and gene regulatory networks, where the theoretical plasticity of interactions is nearly infinite, yet phenotypes in vivo are constrained into a limited subset of practicable configurations.

Application of a Web-Enabled Leg Training System for the Objective Monitoring and Quantitative Analysis of Exercise-Induced Fatigue.

BACKGROUND: Sustained cardiac rehabilitation is the key intervention in the prevention and treatment of many human diseases. However, implementation of exercise programs can be challenging because of early fatigability in patients with chronic diseases, overweight individuals, and aged people. Current methods of fatigability assessment are based on subjective self-reporting such as rating of perceived exertion or require specialized laboratory conditions and sophisticated equipment. A practical approach allowing objective measurement of exercise-induced fatigue would be useful for the optimization of sustained delivery of cardiac rehabilitation to improve patient outcomes. OBJECTIVES: The objective of this study is to develop and validate an innovative approach, allowing for the objective assessment of exercise-induced fatigue using the Web-enabled leg rehabilitation system. METHODS: MedExercise training devices were equipped with wireless temperature sensors in order to monitor their usage by temperature rise in the resistance unit (Δ t °). Since Δ t ° correlated with the intensity and duration of exercise, this parameter was used to characterize participants' leg work output (LWO). Personal smart devices such as laptop computers with wireless gateways and relevant software were used for monitoring of self-control training. Connection of smart devices to the Internet and cloud-based software allowed remote monitoring of LWO in participants training at home. Heart rates (HRs) were measured by fingertip pulse oximeters simultaneously with Δ t ° in 7 healthy volunteers. RESULTS: Exercise-induced fatigue manifested as the decline of LWO and/or rising HR, which could be observed in real-time. Conversely, training at the steady-state LWO and HR for the entire duration of exercise bout was considered as fatigue-free. The amounts of recommended daily physical activity were expressed as the individual Δ t ° values reached during 30-minute fatigue-free exercise of moderate intensity resulting in a mean of 8.1°C (SD 1.5°C, N=7). These Δ t ° values were applied as the thresholds for sending automatic notifications upon taking the personalized LWO doses by self-control training at home. While the mean time of taking LWO doses was 30.3 (SD 4.1) minutes (n=25), analysis of times required to reach the same Δ t ° by the same participant revealed that longer durations were due to fatigability, manifesting as reduced LWO at the later stages of training bouts. Typically, exercising in the afternoons associated with no fatigue, although longer durations of evening sessions suggested a diurnal fatigability pattern. CONCLUSIONS: This pilot study demonstrated the feasibility of objective monitoring of fatigue development in real-time and online as well as retrospective fatigability quantification by the duration of training bouts to reach the same exercise dose. This simple method of leg training at home accompanied by routine fatigue monitoring might be useful for the optimization of exercise interventions in primary care and special populations.

The impact of tropomyosins on actin filament assembly is isoform specific.

Tropomyosin (Tpm) is an α helical coiled-coil dimer that forms a co-polymer along the actin filament. Tpm is involved in the regulation of actin's interaction with binding proteins as well as stabilization of the actin filament and its assembly kinetics. Recent studies show that multiple Tpm isoforms also define the functional properties of distinct actin filament populations within a cell. Subtle structural variations within well conserved Tpm isoforms are the key to their functional specificity. Therefore, we purified and characterized a comprehensive set of 8 Tpm isoforms (Tpm1.1, Tpm1.12, Tpm1.6, Tpm1.7, Tpm1.8, Tpm2.1, Tpm3.1, and Tpm4.2), using well-established actin co-sedimentation and pyrene fluorescence polymerization assays. We observed that the apparent affinity (Kd(app)) to filamentous actin varied in all Tpm isoforms between ∼0.1-5 µM with similar values for both, skeletal and cytoskeletal actin filaments. The data did not indicate any correlation between affinity and size of Tpm molecules, however high molecular weight (HMW) isoforms Tpm1.1, Tpm1.6, Tpm1.7 and Tpm2.1, showed ∼3-fold higher cooperativity compared to low molecular weight (LMW) isoforms Tpm1.12, Tpm1.8, Tpm3.1, and Tpm4.2. The rate of actin filament elongation in the presence of Tpm2.1 increased, while all other isoforms decreased the elongation rate by 27-85 %. Our study shows that the biochemical properties of Tpm isoforms are finely tuned and depend on sequence variations in alternatively spliced regions of Tpm molecules.

A small molecule inhibitor of tropomyosin dissociates actin binding from tropomyosin-directed regulation of actin dynamics.

The tropomyosin family of proteins form end-to-end polymers along the actin filament. Tumour cells rely on specific tropomyosin-containing actin filament populations for growth and survival. To dissect out the role of tropomyosin in actin filament regulation we use the small molecule TR100 directed against the C terminus of the tropomyosin isoform Tpm3.1. TR100 nullifies the effect of Tpm3.1 on actin depolymerisation but surprisingly Tpm3.1 retains the capacity to bind F-actin in a cooperative manner. In vivo analysis also confirms that, in the presence of TR100, fluorescently tagged Tpm3.1 recovers normally into stress fibers. Assembling end-to-end along the actin filament is thereby not sufficient for tropomyosin to fulfil its function. Rather, regulation of F-actin stability by tropomyosin requires fidelity of information communicated at the barbed end of the actin filament. This distinction has significant implications for perturbing tropomyosin-dependent actin filament function in the context of anti-cancer drug development.

An appraisal of the short lateral rotators of the hip joint.

The short lateral rotators (piriformis, obturator internus, superior and inferior gemelli, obturator internus, and quadratus femoris) are functionally important muscles, significantly contributing to hip joint stability. They act as "postural muscles", holding the femoral head in the acetabulum during hip movements, thus are frequently monitored in gait analysis and for muscle rehabilitation post-injury. Despite the need to precisely identify and repair these muscles for stability postoperatively, clinical complications have resulted from the inadequate and inconsistent understanding of their morphological and functional anatomy. Furthermore, the short lateral rotators have complex entheses (osteotendinous insertions on bone) and may be subject to overuse injury in sport. This study aims to review the reported morphology of the short lateral rotators in order to ascertain whether discrepancies exist in our understanding of these muscles, and if further investigation is required to aid in gait analysis, clinical management of hip pathologies, and prevention of overuse injuries. Following a literature search strategy, 59 primary references were retrieved from three databases, with additional 26 anatomical textbooks selected for critical evaluation. Numerous inaccuracies and inconsistencies in the anatomical descriptions of the attachments, patterns of innervation and actions exist, and often insufficiently supported by primary findings. There is also a paucity of information regarding the architectural pattern of the muscles, which would be useful in clarifying the function of these dynamic stabilizers of the hip joint. A better anatomical understanding of these muscles will better inform hip reconstruction and lead to improved surgical outcomes by reducing post-operative complications.

Development of the Internet-Enabled System for Exercise Telerehabilitation and Cardiovascular Training.

OBJECTIVE: Sustained exercise training could significantly improve patient rehabilitation and management of noncommunicable diseases in the community. This study aimed to develop a universal telecare system for delivery of exercise rehabilitation and cardiovascular training services at home. MATERIALS AND METHODS: An innovative bilateral leg training device was equipped with an electronic system for the ongoing measurement of training activities with the device. A single-item parameter reflecting the intensity of training was monitored using several modern telecommunication technologies. According to the application protocol, eight volunteers first tried the device for 30-60 min to determine their personal training capacity. Then, they were provided with equipment to use at home for 4 weeks. Adherence to daily training was assessed by the number of training days per week, training intensity, and duration of training sessions. RESULTS: The system provided reliable recording of training activities with the device using (1) long-term data logging without an ongoing connection to the computer, (2) wireless monitoring and recording of training activities on a stand-alone computer, and (3) a secure cloud-based monitoring over the Internet connection using electronic devices, including smartphones. Overall analysis of recordings and phone feedbacks to participants took only approximately 5 h for the duration of study. CONCLUSIONS: This study, although of a pilot nature, described the comprehensive exercise telerehabilitation system integrating mobile training equipment with personalized training protocols and remote monitoring. A single-item electronic parameter of the system usage facilitated time-effective data management. Wireless connection allowed various locations of device application and several monitoring arrangements ranging from real-time monitoring to long-term recording of exercise activities. A cloud-based software platform enabled management of multiple users at distance. Implementation of this model may facilitate both accessibility and availability of personalized exercise telerehabilitation services. Further studies would validate it in the clinical and healthcare environment.

Automated Management of Exercise Intervention at the Point of Care: Application of a Web-Based Leg Training System.

BACKGROUND: Recent advances in information and communication technology have prompted development of Web-based health tools to promote physical activity, the key component of cardiac rehabilitation and chronic disease management. Mobile apps can facilitate behavioral changes and help in exercise monitoring, although actual training usually takes place away from the point of care in specialized gyms or outdoors. Daily participation in conventional physical activities is expensive, time consuming, and mostly relies on self-management abilities of patients who are typically aged, overweight, and unfit. Facilitation of sustained exercise training at the point of care might improve patient engagement in cardiac rehabilitation. OBJECTIVE: In this study we aimed to test the feasibility of execution and automatic monitoring of several exercise regimens on-site using a Web-enabled leg training system. METHODS: The MedExercise leg rehabilitation machine was equipped with wireless temperature sensors in order to monitor its usage by the rise of temperature in the resistance unit (Δt°). Personal electronic devices such as laptop computers were fitted with wireless gateways and relevant software was installed to monitor the usage of training machines. Cloud-based software allowed monitoring of participant training over the Internet. Seven healthy participants applied the system at various locations with training protocols typically used in cardiac rehabilitation. The heart rates were measured by fingertip pulse oximeters. RESULTS: Exercising in home chairs, in bed, and under an office desk was made feasible and resulted in an intensity-dependent increase of participants' heart rates and Δt° in training machine temperatures. Participants self-controlled their activities on smart devices, while a supervisor monitored them over the Internet. Individual Δt° reached during 30 minutes of moderate-intensity continuous training averaged 7.8°C (SD 1.6). These Δt° were used as personalized daily doses of exercise with automatic email alerts sent upon achieving them. During 1-week training at home, automatic notifications were received on 4.4 days (SD 1.8). Although the high intensity interval training regimen was feasible on-site, it was difficult for self- and remote management. Opportunistic leg exercise under the desk, while working with a computer, and training in bed while viewing television were less intensive than dosed exercise bouts, but allowed prolonged leg mobilization of 73.7 minutes/day (SD 29.7). CONCLUSIONS: This study demonstrated the feasibility of self-control exercise training on-site, which was accompanied by online monitoring, electronic recording, personalization of exercise doses, and automatic reporting of adherence. The results suggest that this technology and its applications are useful for the delivery of Web-based exercise rehabilitation and cardiac training programs at the point of care.

A bilateral rehabilitation system for the lower limbs.

PURPOSE: Bilateral and unilateral training equipment for the upper limbs facilitates rehabilitation after stroke. In this work, we tested the first device designed for bilateral training of the lower limbs. METHOD: Characteristics and usage of the novel MedExercise® ST device were evaluated by four healthy volunteers. A pedometer and temperature sensor were attached to the device and used to measure cadence and intensity of training, respectively. The heart rates of participants were recorded with a fingertip pulse oximeter. Thirty elderly patients assessed usability of the device and completed the survey. RESULTS: It was shown that the device could be operated in sitting and recumbent positions. The resistance levels and range of joint motion were individually adjustable for each leg, allowing both bilateral and unilateral training. When pedals were linked together, one leg could help moving the other leg. Recording of training intensities allowed leg fitness testing, personalized exercise prescription and analysis of self-controlled training. A usability survey demonstrated positive perception of elderly patients towards the device. CONCLUSIONS: This training system has a range of useful features, which can facilitate rehabilitation of the lower limbs via early leg mobilization and self-controlled training. Implications for Rehabilitation Bilateral and unilateral training devices are widely used to improve the effectiveness of upper limb rehabilitation, but there is no analogous equipment available for the lower limbs. Here, we show that the MedExercise® ST training system allows independent exercise of each leg in bilateral and unilateral modes, and objective recording of training activities. Elderly patients attending the exercise rehabilitation clinic demonstrated a positive perception towards usability of this equipment. The results of this study suggest suitability of the system for optimization of lower limb rehabilitation, including early leg mobilisation and self-controlled training.

Selection of reference gene expression in a schizophrenia brain cohort.

OBJECTIVE: In order to conduct postmortem human brain research into the neuropatho-logical basis of schizophrenia, it is critical to establish cohorts that are well-characterized and well-matched. The aim of the present study was therefore to determine if specimen characteristics including: diagnosis, age, postmortem interval (PMI), brain acidity (pH), and/or the agonal state of the subject at death related to RNA quality, and to determine the most appropriate reference gene mRNAs. METHODS: A matched cohort was selected of 74 subjects (schizophrenia/schizoaffective disorder, n = 37; controls, n = 37). Middle frontal gyrus tissue was pulverized, tissue pH was measured, RNA isolated for cDNA from each case, and RNA integrity number (RIN) measurements were assessed. Using quantitative reverse transcription-polymerase chain reaction, nine housekeeper genes were measured and a geomean calculated per case in each diagnostic group. RESULTS: The RINs were very good (mean = 7.3) and all nine housekeeper control genes were significantly correlated with RIN. Seven of nine housekeeper genes were also correlated with pH; two clinical variables, agonal state and duration of illness, did have an effect on some control mRNAs. No major impact of PMI or freezer time on housekeeper mRNAs was detected. The results show that people with schizophrenia had significantly less PPIA and SDHA mRNA and tended to have less GUSB and B2M mRNA, suggesting that these control genes may not be good candidates for normalization. CONCLUSIONS: In the present cohort <10% variability in RINs was detected and the diagnostic groups were well matched overall. The cohort was adequately powered (0.80-0.90) to detect mRNA differences (25%) due to disease. The study suggests that multiple factors should be considered in mRNA expression studies of human brain tissues. When schizophrenia cases are adequately matched to control cases subtle differences in gene expression can be reliably detected.

The importance of brain banks for molecular neuropathological research: The New South Wales Tissue Resource Centre experience.

New developments in molecular neuropathology have evoked increased demands for postmortem human brain tissue. The New South Wales Tissue Resource Centre (TRC) at The University of Sydney has grown from a small tissue collection into one of the leading international brain banking facilities, which operates with best practice and quality control protocols. The focus of this tissue collection is on schizophrenia and allied disorders, alcohol use disorders and controls. This review highlights changes in TRC operational procedures dictated by modern neuroscience, and provides examples of applications of modern molecular techniques to study the neuropathogenesis of many different brain disorders.

Dysregulation of miRNA 181b in the temporal cortex in schizophrenia.

Analysis of global microRNA (miRNA) expression in postmortem cortical grey matter from the superior temporal gyrus, revealed significant up-regulation of miR-181b expression in schizophrenia. This finding was supported by quantitative real-time RT-PCR analysis of miRNA expression in a cohort of 21 matched pairs of schizophrenia and non-psychiatric controls. The implications of this finding are substantial, as this miRNA is predicted to regulate many target genes with potential significance to the development of schizophrenia. They include the calcium sensor gene visinin-like 1 (VSNL1) and the ionotropic AMPA glutamate receptor subunit (GRIA2), which were found to be down-regulated in the same cortical tissue from the schizophrenia group. Both of these genes were also suppressed in miR-181b transfected cells and shown to contain functional miR-181b miRNA recognition elements by reporter gene assay. This study suggests altered miRNA levels could be a significant factor in the dysregulation of cortical gene expression in schizophrenia.

Abnormal pathways in the genu of the corpus callosum in schizophrenia pathogenesis: a proteome study.

Abnormalities within the corpus callosum (CC) have been identified in schizophrenia brains and are thought to affect inter-hemispheric communication, which in-turn is postulated to underlie some schizophrenia symptoms. Furthermore, hemisphere asymmetry of fractional anisotropy, detected by diffusion tensor imaging, left-higher-than-right- has been observed in normal individuals in the CC genu. This asymmetry is significantly reduced in the left CC genu of first-episode and chronic schizophrenia subjects. We examined the protein expression profile of the CC genu, including the profiles from the left and right hemisphere, in schizophrenia brains compared to controls using two-dimensional gel electrophoresis and mass spectrometry techniques. Proteins involved in cytoskeletal structure and function, neuroprotective function and energy metabolism were identified as differentially expressed, suggesting these proteins may underlie abnormal CC genu structure and function. Proteins in these functional categories also displayed different expression levels in the left CC genu compared to the right in both control and schizophrenia brains and therefore may be involved in normal CC asymmetry and reduced asymmetry in schizophrenia individuals. This initial pool of protein candidates and abnormal functional pathways opens up avenues for further investigation of molecular mechanisms involving the CC in schizophrenia pathogenesis and symptoms.

Altered proteins of the anterior cingulate cortex white matter proteome in schizophrenia.

Alterations in the circuitry between and within different brain regions including the anterior cingulate cortex (ACC) is implicated in the neuropathology of schizophrenia. The involvement of white matter in schizophrenia is becoming increasingly apparent with reports of structural, morphological and genetic alterations occurring in the disease. The 2-DE was employed to reveal significantly altered proteins within the ACC white matter proteome in a schizophrenia cohort (n = 10) relative to controls (n = 10). From the 423 matched spots between the two groups, the levels of 32 protein spots were altered in the schizophrenia ACC white matter. Of these, 30 spots were identified using MS. The majority of the altered proteins in schizophrenia function in metabolism, the cytoskeleton, and the synapse. These proteomic data suggest that the brain circuitry involving the ACC white matter tracts is altered in schizophrenia, possibly caused by depleted glucose metabolism and altered structural components of this region.

Failure to support a genetic contribution of AKT1 polymorphisms and altered AKT signaling in schizophrenia.

The protein kinase v-akt murine thymoma viral oncogene homolog (AKT) gene family comprises three human homologs that phosphorylate and inactivate glycogen synthase kinase 3beta (GSK3beta). Studies have reported the genetic association of AKT1 with schizophrenia. Additionally, decreased AKT1 protein expression and the reduced phosphorylation of GSK3beta were reported in this disease, leading to a new theory of attenuated AKT1-GSK3beta signaling in schizophrenia pathogenesis. We have evaluated this theory by performing both genetic and protein expression analyses. A family based association test of AKT1 did not show association with schizophrenia in Japanese subjects. The expression levels of total AKT, AKT1 and phosphorylated GSK3beta detected in the schizophrenic brains from two different brain banks also failed to support the theory. In addition, no attenuated AKT-GSK3beta signaling was observed in the lymphocytes from Japanese schizophrenics, contrasting with previous findings. Importantly, we found that the level of phosphorylated GSK3beta at Ser9 tended to be inversely correlated with postmortem intervals, and that the phosphorylation levels of AKT were inversely correlated with brain pH, issues not assessed in the previous study. These data introduce a note of caution when estimating the phosphorylation levels of GSK3beta and AKT in postmortem brains. Collectively, this study failed to support reduced signaling of the AKT-GSK3beta molecular cascade in schizophrenia.

Distinct endocrine effects of chronic haloperidol or risperidone administration in male rats.

Antipsychotic drugs have been used effectively for the treatment of schizophrenia symptoms, but they are often associated with metabolic side effects such as weight gain and endocrine disruptions. To investigate the possible mechanisms of antipsychotic-induced metabolic effects, we studied the impact of chronic administration of a typical antipsychotic drug (haloperidol) and an atypical antipsychotic (risperidone) to male rats on food intake, body weight, adiposity, and the circulating concentrations of hormones and metabolites that can influence energy homeostasis. Chronic (28days) haloperidol administration had no effect on food intake, weight gain or adiposity in male rats, whereas risperidone treatment resulted in a transient reduction in food intake and significantly reduced body weight gain compared to vehicle-treated control rats. Whereas neither antipsychotic had any effect on serum lipid profiles, glucose tolerance or the circulating concentrations of hormones controlled by the hypothalamo-pituitary-thyroid (free T4), -adrenal (corticosterone), -somatotropic (IGF-1), or -gonadotropic axes (testosterone), haloperidol increased circulating insulin levels and risperidone increased serum glucagon levels. This finding suggests that haloperidol or risperidone induce distinct metabolic effects. Since metabolic disorders such as obesity and type 2 diabetes mellitus represent serious health issues, understanding antipsychotic-induced endocrine and metabolic effects may ultimately allow better control of these side effects.

Effects of chronic risperidone treatment on the striatal protein profiles in rats.

Extrapyramidal symptoms (EPS) commonly occur as side effects of antipsychotic drugs (APDs) and are most likely to arise when the occupancy of dopamine D(2) receptors in the striatum by these drugs exceeds 80%. We aimed to characterize changes in the protein expression profile in the striatum of rats after chronic (4 week) supra-therapeutic (EPS-inducing) treatment with risperidone (RIS), an atypical antipsychotic drug. Administration of RIS (2.1 mg/kg/day, via subcutaneous osmotic minipumps) induced significant vacuous chewing movements and catalepsy in male Sprague-Dawley rats over a 28-day treatment period compared with a vehicle (VEH) control group (n=12) (Karl et al., unpublished observation). Using two-dimensional gel electrophoresis (2DE), total protein extracts from the rat brain striatum were separated and protein expression was analyzed by Phoretix 2D Expression and Image Beta V4.02 software followed by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). 2DE gels resolved up to 450 protein spots, presumably different proteins and/or their isoforms. There were 30 protein spots showing statistically significant different densities between the RIS- and VEH-treated groups. All 30 proteins were successfully identified by MALDI-TOF MS, 28 of these were divided into groups based on their known functions. These included metabolic, signaling, transport, protein metabolism, chaperone, DNA binding and cell cycle categories. We conclude that chronic risperidone treatment accompanied by an EPS-like behavioral phenotype results in alterations in the striatal protein profile possibly subsequent to blockade of dopaminergic systems. These results suggest that possible mechanisms involved in APD-induced EPS include metabolic dysfunction and oxidative stress.

Behavioural effects of chronic haloperidol and risperidone treatment in rats.

The therapeutic properties of typical antipsychotic drugs (APDs) such as haloperidol in schizophrenia treatment are mainly associated with their ability to block dopamine D2 receptors. This blockade is accompanied by side effects such as extrapyramidal symptoms (EPS). Atypical APDs such as risperidone have superior therapeutic efficacy possibly due to their activity at multiple receptors (in particular 5-HT2A receptors). Although the risk of EPS is significantly lower in atypical than in typical APDs, it is not negligible. To investigate and compare the behavioural profile and EPS-asssociated side effects of haloperidol and risperidone APD treatment we applied a multi-tiered, comprehensive behavioural phenotyping approach. Sprague-Dawley rats were treated chronically (28 days) with supratherapeutic EPS-inducing doses of haloperidol and risperidone using osmotic minipumps. Domains such as motor activity, exploration, memory, and anxiety were analysed together with EPS assessment ("early onset" vacuous chewing movements and catalepsy). Both APDs produced diminished motor activity and exploration, impaired working memory performances, and increased anxiety levels. These effects were more pronounced in haloperidol-treated animals. Chronic APD treatment also caused a time-course dependent elevation of EPS-like symptoms. Risperidone-treated animals showed a catalepsy-like phenotype, which differed to that of haloperidol-treated rats, indicating that processes other than the anticipated dopaminergic mechanisms are underlying this phenomenon. These EPS-related phenotypes are consistent with reported EPS-inducing D2 receptor occupancies of around 80%. Differences in the behavioural profile of haloperidol and risperidone, which were revealed by a comprehensive phenotyping strategy, are likely due to the unique receptor activation profiles of these APDs.