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1.
Can J Psychiatry ; 68(3): 187-199, 2023 03.
Article in English | MEDLINE | ID: mdl-36124379

ABSTRACT

OBJECTIVES: A patient's death by suicide is a common experience for psychiatrists, ranging from 33% to 80%, however, research about the impact of patient suicide on psychiatrists is limited to a few survey studies. This study had three main objectives: (1) understanding the emotional and behavioural impact of a patient's suicide on psychiatrists, (2) exploring if and how the experience of a patient's suicide results in changes in psychiatrist practice patterns, and (3) understanding the tangible steps that psychiatrists and institutions take to manage the emotional and behavioural impact of patient suicide on psychiatrists. METHODS: Eighteen psychiatrists were recruited using snowball sampling and interviewed to collect demographic data, followed by an in-depth exploration of their experiences of patient suicide. Interviews were then transcribed verbatim and analysed using constructivist grounded theory. RESULTS: Study participants described strong emotional reactions in response to patient suicide. Emotional reactions were mediated by a physician, patient, relationship and institutional factors. While psychiatrists did not change the acuity or setting of their practice in response to patient suicide, they made several changes in their practice, including increased caution regarding discharges and passes from inpatient units, more thorough documentation and continuing education about suicide. CONCLUSIONS: Patient suicide has a profound impact on psychiatrists and based on the findings of this study, we propose steps that psychiatrists and institutions can take to manage the emotional, psychological and behavioural burden of this event.


Subject(s)
Delivery of Health Care , Physicians , Psychiatry , Suicide Prevention , Suicide , Humans , Male , Emotions , Physicians/psychology , Psychiatry/education , Psychiatry/standards , Suicide/psychology , Surveys and Questionnaires , Physician-Patient Relations , Clinical Competence , Delivery of Health Care/standards
2.
Community Ment Health J ; 59(7): 1352-1363, 2023 10.
Article in English | MEDLINE | ID: mdl-37097490

ABSTRACT

Across jurisdictions, the use of 'leverage' to promote adherence to mental health treatment is widespread. However, little research exists on the possible association between the application of leverage and personal recovery. We examined the prevalence of various forms of leverage in a Canadian context and compared these rates with those in other jurisdictions. Additionally, we examined the relationship between two prominent forms of leverage (financial and housing) and the experience of personal recovery. Structured interviews were conducted with people receiving community-based mental health care in Toronto, Canada. Rates of overall leverage in our sample were similar to rates reported in other jurisdictions. Personal recovery was negatively associated with financial leverage but was not associated with housing leverage. Our results highlight the importance of separately examining the relationship of specific forms of leverage and personal recovery and raise questions for future research about the possible effect of financial leverage on recovery.


Subject(s)
Community Mental Health Services , Mental Disorders , Humans , Mental Disorders/epidemiology , Mental Disorders/therapy , Cross-Sectional Studies , Community Mental Health Services/methods , Prevalence , Canada/epidemiology
3.
BMC Psychiatry ; 20(1): 230, 2020 05 13.
Article in English | MEDLINE | ID: mdl-32404082

ABSTRACT

BACKGROUND: The risk and recovery paradigms are the dominant frameworks informing forensic mental health services and have been the focus of increasing research interest. Despite this, there are significant gaps in our understanding of the nature of mental health recovery in forensic settings (i.e., 'secure recovery'), and specifically, the key elements of recovery as perceived by forensic patients and their treatment providers. Importantly, we know little about how patients perceive the forensic mental health system, to what extent they see it as fair and legitimate, and how these perceptions impact upon treatment engagement, risk for adversity, and progress in recovery. METHODS: In this prospective, mixed-methods study, we investigate patient perceptions of procedural justice and coercion within the context of the forensic mental health system in Ontario, Canada (final N = 120 forensic patients and their primary care providers). We elicit patient self-assessments of risk and progress in recovery, and assess the degree of concordance with clinician-rated estimates of these constructs. Both qualitative and quantitative methods are used to assess the degree to which patient perceptions of coercion, fairness and legitimacy impact upon their level of treatment engagement, risk for adversity and progress in recovery. A prospective, two-year follow-up will investigate the impact of patient and clinician perspectives on outcomes in the domains of forensic hospital readmission, criminal reoffending, and rate of progress through the forensic system. DISCUSSION: Results from this mixed-methods study will yield a rich and detailed account of patient perceptions of the forensic mental health system, and specifically whether perceptions of procedural fairness, justice and legitimacy, as well as perceived coercion, systematically influence patients' risk for adversity, their ability to progress in their recovery, and ultimately, advance through the forensic system towards successful community living. Findings will provide conceptual clarity to the key elements of secure recovery, and illuminate areas of similarity and divergence with respect to how patients and clinicians assess risk and recovery needs. In doing so, knowledge from this study will provide a deep understanding of factors that promote patient safety and recovery, and provide a foundation for optimizing the forensic mental health system to improve patient outcomes.


Subject(s)
Coercion , Mental Disorders , Patients/psychology , Social Justice , Adult , Female , Humans , Male , Ontario , Prospective Studies
4.
Can J Psychiatry ; 64(10): 726-735, 2019 Oct.
Article in English | MEDLINE | ID: mdl-30895806

ABSTRACT

OBJECTIVE: Community treatment orders (CTOs) have been used in the treatment of some individuals with serious mental illness who fail to adhere to their psychiatric treatment, leading to frequent hospitalization. This article examines perceptions and knowledge of CTOs amongst outpatient service users in Toronto, Canada. METHOD: Service users under a CTO were matched to a comparison control group of voluntary outpatients (n = 69 in each group). Participants were interviewed using a series of questionnaires aimed at assessing instead of evaluating their knowledge and perceptions of CTOs, as well as understanding their views about the utility and impact of CTOs in the treatment of individuals with mental health issues. RESULTS: Participants in the CTO group knew significantly more about CTO processes, restrictions, and procedural protections than the control group. Both groups thought that a CTO could improve certain individuals' mental health. The control group felt more strongly that a CTO could improve a service user's physical health by providing better access to care and closer monitoring (P = 0.019) while a significant proportion of the CTO group thought that being on a CTO was better than being in the hospital (P = 0.001) and that service users should be able to contest their CTO (P = 0.001). In addition, CTO group participants were significantly more optimistic about the potential positive impact of CTOs on other service users' quality of life (P = 0.008) and mental health (P = 0.023) compared to themselves. CONCLUSIONS: In general, both groups viewed CTOs as potentially capable of positively affecting treatment and lives of some individuals with mental illness.


Subject(s)
Community Mental Health Services/statistics & numerical data , Health Knowledge, Attitudes, Practice , Involuntary Treatment/statistics & numerical data , Mental Disorders/therapy , Mentally Ill Persons/statistics & numerical data , Outpatients/statistics & numerical data , Adult , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Ontario
5.
BMC Psychiatry ; 18(1): 20, 2018 01 24.
Article in English | MEDLINE | ID: mdl-29368586

ABSTRACT

BACKGROUND: Across many jurisdictions, adults with complex mental health and social needs face challenges accessing appropriate supports due to system fragmentation and strict eligibility criteria of existing services. To support this underserviced population, Toronto's local health authority launched two novel community mental health models in 2014, inspired by Flexible Assertive Community Team principles. This study explores service user and provider perspectives on the acceptability of these services, and lessons learned during early implementation. METHODS: We purposively sampled 49 stakeholders (staff, physicians, service users, health systems stakeholders) and conducted 17 semi-structured qualitative interviews and 5 focus groups between October 23, 2014 and March 2, 2015, exploring stakeholder perspectives on the newly launched team based models, as well as activities and strategies employed to support early implementation. Interviews and focus groups were audio recorded, transcribed verbatim and analyzed using thematic analysis. RESULTS: Findings revealed wide-ranging endorsement for the two team-based models' success in engaging the target population of adults with complex service needs. Implementation strengths included the broad recognition of existing service gaps, the use of interdisciplinary teams and experienced service providers, broad partnerships and collaboration among various service sectors, training and team building activities. Emerging challenges included lack of complementary support services such as suitable housing, organizational contexts reluctant to embrace change and risk associated with complexity, as well as limited service provider and organizational capacity to deliver evidence-based interventions. CONCLUSIONS: Findings identified implementation drivers at the practitioner, program, and system levels, specific to the implementation of community mental health interventions for adults with complex health and social needs. These can inform future efforts to address the health and support needs of this vulnerable population.


Subject(s)
Attitude of Health Personnel , Community Mental Health Services/organization & administration , Health Services Accessibility , Patient Care Team , Patient Satisfaction , Adolescent , Adult , Aged , Female , Focus Groups , Health Services Needs and Demand , Humans , Interviews as Topic , Middle Aged , Quebec , Urban Health , Workforce , Young Adult
6.
Can J Psychiatry ; 63(11): 757-765, 2018 Nov.
Article in English | MEDLINE | ID: mdl-29614866

ABSTRACT

OBJECTIVE: Since the deinstitutionalization of psychiatric services around the world, the scope of outpatient psychiatric care has also increased to better support treatment access and adherence. For those with serious mental illness who may lack insight into their own illness, available interventions include coercive community practices such as mandated community treatment orders (CTOs). This paper examines the perceptions of coercion among service users treated with a CTO. METHOD: We used a cross-sectional comparative design where service users treated under a CTO were matched to a comparison group of voluntary psychiatric outpatients. Both groups were receiving intensive community mental health services (n = 69 in each group). Participants were interviewed using a series of questionnaires aimed at evaluating their perceptions of coercion and other aspects of the psychiatric treatment. RESULTS: The level of coercion reported by service users treated under a CTO was significantly higher than that in the comparison group. However, in adjusted analyses, service users' perception of coercion, irrespective of their CTO status, was directly correlated with their previous experience with probation and inversely correlated with the sense of procedural justice in their treatment. CONCLUSIONS: Evaluation of psychiatric service users' experiences of coercion should consider their past and current involvement with other types of coercive measures, particularly history of probation. Clinicians may be able to minimize these experiences of coercion by incorporating procedural justice principles into their practice.

8.
Int J Law Psychiatry ; 88: 101873, 2023.
Article in English | MEDLINE | ID: mdl-36950980

ABSTRACT

In the era of on-going efforts to empower persons with mental illness to be independent decision makers as informed by the United Nations' Convention on the Rights of Persons with Disability (CRPD), family members acting as substitute decision makers (SDM) for people suffering from disabling serious mental illness (SMI) remain an integral part of the medical-legal system in psychiatric care in many parts of the world, including Canada; yet their experiences and perspectives are rarely studied. This explorative qualitative study examines the lived experiences and reflections of 14 family member SDMs in Toronto, Canada. Five key themes related to being SDM emerged: 1) Varied subjective understanding of the responsibility and authority of the SDM role; 2) Varied role demands and impact on SDMs' lives; 3) Challenges in dealing with the mental health system; 4) Leveraging decision making status to promote patient care; and 5) SDM role impact on family relationships. The need to improve SDM understanding of their role, acknowledging their value and care-taker burden, finding a balance for their involvement, and improving their support in efforts to enhance care for the patients are discussed.


Subject(s)
Chiroptera , Disabled Persons , Mental Disorders , Humans , Animals , Mental Disorders/psychology , Mental Health , Decision Making
9.
Psychiatr Rehabil J ; 2023 Nov 16.
Article in English | MEDLINE | ID: mdl-37971817

ABSTRACT

OBJECTIVE: In Canada and elsewhere, making treatment decisions for a person with serious mental illness (SMI) who was found incapable for treatment decisions via a substitute decision maker (SDM) is the norm. This practice is often called into question from a rights-based perspective. The literature on the views of affected individuals is limited. We explore the experiences of adults with SMI who have had SDMs to gain more in-depth understanding. METHOD: We conducted semistructured interviews with 11 consumers of psychiatric services who have had experiences with SDM (range 1-12 years) at an urban hospital in Toronto, Canada. RESULTS: Thematic analysis showed five main themes and related subthemes, including: (1) strong dissatisfaction with and rejection of the SDM's role and purpose; (2) pervasive sense of stigma associated with having a SDM; (3) ongoing struggles to gain autonomy; (4) mixed changes in relationship with and views about SDM; and (5) views on how to improve SDM process. CONCLUSION AND IMPLICATIONS FOR PRACTICE: Our study highlights substantial dissatisfaction with the current SDM system and approaches among adults with SMI who have had SDMs. Issues of stigma and struggles to regain autonomy are prevalent. We discuss the personal, clinical, and social-legal contexts in which they occur, particularly in light of the United Nations' Convention on the Rights of Persons with Disabilities that calls for replacing SDMs with supported decision making. Rights-based approaches to care carry substantial practice implications and call for thoughtful change management. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

10.
Can J Psychiatry ; 57(6): 359-65, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22682573

ABSTRACT

OBJECTIVE: Some literature suggests that compulsory community treatment orders (CTOs) are effective in reducing hospitalizations in a subgroup of psychiatric patients with histories of repeated hospitalization, allowing them to be treated in the community under less restrictive measures. However, studies have yielded contradictory findings, in part because of methodological differences. Our study examines the effectiveness of CTOs in reducing hospitalizations and increasing community tenure of such patients. METHOD: The sample included all psychiatric patients who had been given a CTO during a 9-year period at 2 of McGill University's hospitals. This is a naturalistic, observational, retrospective, before-and-after study where patients acted as their own control subjects. We examined variables, including the number, duration, and time to psychiatric admissions, comparing 4 time periods: early, pre-index, index (when the first CTO was in force), and post-index periods. The total study duration per subject encompasses the longest period of observation within existing studies in Canada. RESULTS: Psychiatric patients with histories of frequent readmissions demonstrated a significant reduction in their number of hospitalizations as well as an increase in the median time to re-hospitalization, during the period when they were treated under a CTO. This effect of CTO was sustained even after the CTO had expired. CONCLUSIONS: Our study suggests that CTOs are effective in assisting psychiatric patients with histories of repeated hospitalizations to live and be treated in the community, diminishing the occurrence of frequent hospitalization.


Subject(s)
Commitment of Mentally Ill/legislation & jurisprudence , Community Mental Health Services/legislation & jurisprudence , Mental Disorders/therapy , Prisoners/psychology , Adult , Commitment of Mentally Ill/statistics & numerical data , Community Mental Health Services/statistics & numerical data , Female , Follow-Up Studies , Hospitals, University , Humans , Insanity Defense , Kaplan-Meier Estimate , Male , Mental Disorders/epidemiology , Mental Disorders/psychology , Middle Aged , Neurocognitive Disorders/epidemiology , Neurocognitive Disorders/psychology , Neurocognitive Disorders/therapy , Patient Readmission/statistics & numerical data , Personality Disorders/epidemiology , Personality Disorders/psychology , Personality Disorders/therapy , Psychiatric Department, Hospital , Psychotic Disorders/epidemiology , Psychotic Disorders/psychology , Psychotic Disorders/therapy , Quebec , Retrospective Studies , Schizophrenia/epidemiology , Schizophrenia/therapy , Treatment Outcome
11.
Gen Hosp Psychiatry ; 72: 15-22, 2021.
Article in English | MEDLINE | ID: mdl-34214934

ABSTRACT

OBJECTIVE: Various methods are used to induce or pressure patients into being more adherent with treatment; collectively, we can describe them as leverage. Leverage strategies are common in psychiatric services, and may carry unintended, potentially negative effects. We examine their relationships to experiences and impact of stigma. METHODS: Data from 137 researcher-administered surveys with adult general psychiatry patients from hospital and community psychiatric services in Toronto, Canada were analyzed, including socio-demographics, service use history, current level of symptoms, insight into mental illness, and stigma scores. Descriptive and bivariate analyses were performed to guide generalized linear models to examine the relationships between multiple domains of leverage and experiences and impact of stigma. RESULTS: Use of leverage strategies is prevalent, ranging from outpatient commitment (10.2%) to financial (21.2%) to access to children or family (31.2%). Regression analyses show being female, having high psychiatric symptomology, financial leverage, and family and/or child access leverage were significantly correlated with stigma experience; similarly, these same factors, except for being female, were also associated with stigma impact. CONCLUSION: This cross-sectional study shows a significant association between use of some types of leverage and experience and impact of stigma in general psychiatry patients. Care and balance between good intentioned but potentially stigmatizing leveraging practices should be actively considered in clinical decisions to avoid the unintended negative effects.


Subject(s)
Mental Disorders , Psychiatry , Adult , Child , Cross-Sectional Studies , Female , Humans , Mental Disorders/psychology , Mental Disorders/therapy , Outpatients , Patient Outcome Assessment , Social Stigma
12.
Int J Law Psychiatry ; 68: 101515, 2020.
Article in English | MEDLINE | ID: mdl-32033692

ABSTRACT

The Consent and Capacity Board (CCB) of Ontario is an independent administrative tribunal that adjudicates on matters of consent to medical treatment including involuntary admission to a psychiatric facility and findings of incapacity with regard to treatment decisions. This study explores the perspectives of multiple stakeholders on procedural justice in CCB hearings in Ontario. Using purposeful and snowball sampling, participants including CCB panel members and staff, patients, and other professionals (e.g., lawyers, psychiatrists) were recruited from different sites across the city of Toronto. Using focus groups (n = 10) and individual interviews (n = 14), data were collected from 44 participants including 6 patients and 38 other stakeholders who have participated in CCB hearings. Using thematic analysis, we identified five themes - (i) Inclusiveness (ii) Respect (iii) Fairness (iv) Finding and using one's voice, and (v) Balancing interests. Findings revealed that despite efforts by CCB panel members to conduct hearings in an inclusive manner, the legalistic nature of the proceedings, as well as patients' uncertainty regarding the benefits of testifying, may be perceived as barriers to patients' meaningful participation. There was a general belief that patients are respected during CCB hearings by physicians and panel members; however, patients and their lawyers had mixed perceptions about this issue. Almost all stakeholders, excluding CCB panel members, perceived that CCB hearings were not procedurally fair. Our findings indicate that CCB hearings, as currently conducted, are not perceived as procedurally just by many of the relevant stakeholders. This perception may improve by adopting a more informal and less adversarial hearing format as well as enhancing patients' education and understanding of the CCB hearings' processes and potential outcomes.


Subject(s)
Decision Making , Involuntary Treatment, Psychiatric , Judicial Role , Mental Competency/legislation & jurisprudence , Mentally Ill Persons/legislation & jurisprudence , Treatment Refusal/legislation & jurisprudence , Humans , Ontario , Qualitative Research
14.
Int J Law Psychiatry ; 57: 122-130, 2018.
Article in English | MEDLINE | ID: mdl-29548499

ABSTRACT

As medical, ethical and clinical effectiveness debates about the use of compulsory psychiatric treatment continues, it is important to further explore the actual experiences and perspectives of all relevant stakeholders in community treatment orders (CTOs). This qualitative pilot study engaged a total of twenty-seven clients, their family members, and care providers in Toronto, Canada. Semi-structured, one-on-one interviews were conducted between February and July 2013 and analyzed using thematic analysis. Top key themes from all the participants identified include, among others: 1) clients' experiences of coercion while treated under CTO, but a preference for CTOs compared to involuntary hospitalization, nevertheless; 2) limited real opportunities for collaboration in treatment decisions expressed by clients and family members; 3) acceptance of the potential for clinical recovery on CTOs while debating the role of CTO in a broader recovery journey by all stakeholders; 4) general preservation of therapeutic relationships between clients and care providers, while acknowledging the tension of taking on an "enforcer" role by providers; and 5) existence of different avenues for asserting agency by clients. The findings of this research illuminate the nuanced, complex, and adaptive perspectives held by different stakeholders, point to the importance of preserving and enhancing procedural justice in their use, and alert the field to incorporate recovery-based approaches in this controversial practice that is a widely and commonly used clinical tool across many jurisdictions.


Subject(s)
Attitude of Health Personnel , Commitment of Mentally Ill/statistics & numerical data , Community Mental Health Services/organization & administration , Involuntary Treatment, Psychiatric/organization & administration , Mental Disorders/therapy , Humans , Mental Disorders/psychology , Ontario , Pilot Projects , Qualitative Research
15.
Int J Ment Health Nurs ; 27(2): 891-900, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29044920

ABSTRACT

As police officers are often the first responders to mental health crises, a number of approaches have emerged to support skilled police crisis responses. One such approach is the police-mental health co-responding team model, whereby mental health nurses and police officers jointly respond to mental health crises in the community. In the present mixed-method study, we evaluated outcomes of co-responding team interactions at a large Canadian urban centre by analysing administrative data for 2743 such interactions, and where comparison data were available, compared them to 16 226 police-only team responses. To understand service user experiences, we recruited 15 service users for in-depth qualitative interviews, and completed inductive thematic analysis. Co-responding team interactions had low rates of injury and arrest, and compared to police-only teams, co-responding teams had higher overall rates of escorts to hospital, but lower rates of involuntary escorts. Co-responding teams also spent less time on hospital handovers than police-only teams. Service users valued responders with mental health knowledge and verbal de-escalation skills, as well as a compassionate, empowering, and non-criminalizing approach. Current findings suggest that co-responding teams could be a useful component of existing crisis-response systems.


Subject(s)
Mental Health Services , Police , Urban Health Services , Adolescent , Adult , Crisis Intervention/methods , Female , Humans , Male , Mental Disorders/therapy , Middle Aged , Treatment Outcome , Young Adult
16.
Psychiatr Serv ; 68(9): 867-869, 2017 Sep 01.
Article in English | MEDLINE | ID: mdl-28806892

ABSTRACT

To serve a wider range of patients with serious mental illness and develop more integrated, flexible services, investigators in Toronto redesigned a high-fidelity assertive community treatment (ACT) team according to flexible ACT (FACT) principles. FACT, developed in the Netherlands, merges ACT and intensive case management (ICM) services. This model holds the promise of an affordable approach to addressing unmet service needs in community mental health, particularly for patients with complex health issues, by widening the ACT admission criteria. This enables the team to serve more patients and provide both ACT and ICM services according to patients' needs while allowing continuity of care.


Subject(s)
Case Management , Community Mental Health Services/methods , Mental Disorders/therapy , Urban Population , Adult , Humans , Ontario
18.
Psychiatr Serv ; 67(1): 16-28, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26423101

ABSTRACT

OBJECTIVE: Various forms of compulsory psychiatric community treatment orders (CTOs) are commonly utilized internationally. CTOs remain contentious because of the ethical implications of coercing patients to receive treatment. Understanding patients' experience of CTOs can assist in the development of more patient-centered and recovery-focused community care. This review examined the relationship between CTOs and patients' perceptions of coercion in the literature. METHODS: A search of key terms relating to CTOs and patients' perceptions of coercion was conducted of relevant databases from their inception to March 31, 2014. Publications were included if they were peer reviewed, reported on original research, surveyed or interviewed patients who were or had been subject to a CTO, and were written in English. Factors influencing patients' perceptions of coercion, including the regional context of the studies, were identified. RESULTS: Twenty-three primary research articles, reporting on 14 studies from seven countries, were included. Evidence indicated that CTOs may contribute to a patient's sense of coercion, with marked variations among studies in the levels of coercion. Contextual factors, including perceptions of alternatives to CTOs, the presence of additional forms of leverage in patients' lives, and the process of CTO initiation and enforcement, may mitigate or enhance perceptions of coercion. CONCLUSIONS: Coercive elements of CTOs may be reduced through increased patient access to information, better working relationships with service providers, and accessible, fair processes. The coercive aspects of CTOs should be seen as part of a broader understanding of the daily pressures and leverage applied in outpatient psychiatric treatment.


Subject(s)
Coercion , Mental Disorders/psychology , Mental Disorders/therapy , Patients/psychology , Psychotherapy/methods , Ambulatory Care , Community Mental Health Services , Humans , Randomized Controlled Trials as Topic
19.
J Neurosci ; 23(15): 6238-44, 2003 Jul 16.
Article in English | MEDLINE | ID: mdl-12867508

ABSTRACT

We discovered a novel alternatively spliced form of synaptotagmin I (Syt I). This splicing event is conserved over evolution and, in Aplysia, results in a two amino acid insert in the juxtamembrane domain of Syt I (Syt IVQ). Both Syt I and Syt IVQ are localized to synaptic vesicles; however, we also observed punctae that contained one or the other spliced products. Both Syt I and Syt IVQ are phosphorylated at the adjacent PKC site. Overexpression of Syt IVQ, but not of Syt I, in Aplysia neurons blocked the ability of serotonin to reverse synaptic depression. This effect is upstream of PKC activation, because neither Syt IVQ nor Syt I blocked the effects of phorbol esters on reversing synaptic depression or the effects of serotonin on facilitating nondepressed synapses. Our results demonstrate a physiological role for splicing in the juxtamembrane domain of Syt I.


Subject(s)
Calcium-Binding Proteins , Membrane Glycoproteins/metabolism , Nerve Tissue Proteins/metabolism , Neurotransmitter Agents/metabolism , Alternative Splicing , Amino Acid Sequence , Animals , Aplysia , Base Sequence , Cells, Cultured , Membrane Glycoproteins/genetics , Molecular Sequence Data , Nerve Tissue Proteins/genetics , Neural Inhibition/drug effects , Neural Inhibition/physiology , Neurons, Afferent/drug effects , Neurons, Afferent/metabolism , Patch-Clamp Techniques , Phorbol Esters/pharmacology , Phosphorylation , Protein Isoforms/genetics , Protein Isoforms/metabolism , Protein Kinase C/drug effects , Protein Kinase C/metabolism , Sequence Homology, Amino Acid , Serotonin/pharmacology , Synapses/metabolism , Synaptic Transmission/drug effects , Synaptic Vesicles/metabolism , Synaptotagmin I , Synaptotagmins
20.
J Neurophysiol ; 97(1): 134-43, 2007 Jan.
Article in English | MEDLINE | ID: mdl-16971689

ABSTRACT

Activation of phosphokinase C (PKC) can increase transmitter release at sensory-motor neuron synapses in Aplysia, but the target of PKC phosphorylation has not been determined. One putative target of PKC at synapses is the synaptosomal-associated protein of 25 kDa (SNAP-25), a member of the SNARE protein complex implicated in synaptic vesicle docking and fusion. To determine whether PKC regulated transmitter release through phosphorylation of SNAP-25, we cloned Aplysia SNAP-25 and expressed enhanced green fluorescent protein (EGFP)-coupled SNAP-25 constructs mutated at the PKC phosphorylation site Ser198 in Aplysia sensory neurons. We found several distinct effects of expression of EGFP-SNAP-25 constructs. First, the rates of synaptic depression were slowed when cells contained SNAP-25 with phosphomimetic residues Glu or Asp. Second, PDBu-mediated increases in transmitter release at naïve synapses were blocked in cells expressing nonphosphorylated-state SNAP-25. Finally, expression of EGFP-coupled SNAP-25 but not uncoupled SNAP-25 inhibited 5-HT-mediated reversal of depression and the ability of EGFP-coupled SNAP-25 to inhibit the reversal of depression was affected by changes at Ser198. These results suggest SNAP-25 and phosphorylation of SNAP-25 by PKC can regulate transmitter release at Aplysia sensory-motor neuron synapses by a number of distinct processes.


Subject(s)
Motor Neurons/metabolism , Neurons, Afferent/metabolism , Neurotransmitter Agents/metabolism , Presynaptic Terminals/metabolism , Protein Kinase C/metabolism , Synaptosomal-Associated Protein 25/metabolism , Animals , Aplysia , Cells, Cultured , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Motor Neurons/cytology , Motor Neurons/drug effects , Neural Inhibition/drug effects , Neural Inhibition/physiology , Neurons, Afferent/cytology , Neurons, Afferent/drug effects , Patch-Clamp Techniques , Phosphorylation , Presynaptic Terminals/drug effects , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Serotonin/metabolism , Serotonin/pharmacology , Synaptic Transmission/drug effects , Synaptic Transmission/physiology , Synaptosomal-Associated Protein 25/genetics
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