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1.
Psychol Health ; : 1-13, 2024 Jan 08.
Article in English | MEDLINE | ID: mdl-38189349

ABSTRACT

OBJECTIVES: Self-directed ageism is the application of stereotypic age-related beliefs to oneself, and is known to negatively impact health-related motivation (Levy, 2003;  2022). This study focused on the specific self-directed stereotype that 'age causes illness' and aimed to develop and test a multi-item measure to assess this implicit, limiting belief. METHODS AND MEASURES: Survey data was collected from N = 347 adults in southeastern Idaho (ages 45-65 years old, 60% female). A variety of measures were used to assess the discriminant, convergent and predictive validity of the Age Causes Illness scale including: socio-demographics (age, sex, education), psychosocial resources (personality, optimism, social support, depressive symptoms), health/aging expectations, and indicators of physical health. RESULTS: The seven-item Age Causes Illness scale is reliable and shows an expected pattern of discriminant and convergent correlations with relevant socio-demographic, psychosocial, and aging-related measures. The belief that 'age causes illness,' as assessed with this new scale, is related to both objective and subjective indicators of physical health. CONCLUSIONS: The Age Causes Illness scale is a brief screening tool, potentially applicable in behavioral health settings as an initial step toward discussion of the implicit, and often unchallenged, belief that age alone determines the onset, progression, and offset of illness.

2.
Healthc Policy ; 19(SP): 10-23, 2023 10.
Article in English | MEDLINE | ID: mdl-37850702

ABSTRACT

Comprehensive primary healthcare for patients with complex care needs requires connections to other health services, social services and community supports. This descriptive comparative policy research program used publicly available documents and informant interviews to examine progress toward integrated comprehensive care through the lens of services needed by children and youth (0-25 years) and community-dwelling older adults (≥ 65 years) with high functional health needs. This article describes five projects. The following three findings emerged across all the projects: Canada indeed has multiple health systems; numerous integrated service delivery solutions are being trialled and most focus on medical services; and it is an ongoing challenge for ministries of health to engage physicians and physician associations in integration.


Subject(s)
Health Policy , Social Work , Child , Adolescent , Humans , Aged , Canada
3.
Healthc Policy ; 19(SP): 39-52, 2023 10.
Article in English | MEDLINE | ID: mdl-37850704

ABSTRACT

This paper describes how health and social services are governed and organized across Canada for two patient groups. Governance configurations and governance proximity between primary care and priority health and social services varied markedly between provinces. While the need for integrated service delivery has been made a clear priority during the COVID-19 pandemic, the potential of Canada's healthcare systems has not yet translated into coordinated and integrated care for health services, much less for health and social services. It is time to act on the policy recommendations from commissioned reports over the past two decades that focus on comprehensive, community-based care.


Subject(s)
COVID-19 , Pandemics , Humans , COVID-19/epidemiology , Delivery of Health Care , Canada , Social Work
4.
Healthc Policy ; 19(SP): 24-38, 2023 10.
Article in English | MEDLINE | ID: mdl-37850703

ABSTRACT

Introduction: From a larger study examining policy and program information on how Canadian provinces integrate care services, this study aimed to create "priority lists" of 10-15 services that are "absolutely needed" for care integration. Methodology: A diverse group of over 50 Canadian stakeholders participated in virtual consensus-building using the nominal group technique and a modified e-Delphi method to identify services that focused on two different groups: children and youth with high functional health needs and older adults in functional decline. Results: Three lists - containing services, processes and infrastructure elements - emerged: one per tracer condition group and a consolidated list. The latter identified the following five services as top priority for primary care integration: mental health and addictions services; home care; transition between urgent-emergency-acute care; medication reconciliation in community pharmacies; and respite care. No single social service was a clear priority, but those that mitigate material deprivation emerged within the top 10. Discussion: This humble pan-Canadian study shows that priority services in health and social services are neither well integrated nor connected to primary care. It also suggests that effective policy strategizing for primary care integration for those with complex care needs may require thinking beyond the logic of services - given their siloed organization.


Subject(s)
Emergency Medical Services , Child , Adolescent , Humans , Aged , Canada , Consensus
5.
Healthc Policy ; 19(SP): 53-64, 2023 10.
Article in English | MEDLINE | ID: mdl-37850705

ABSTRACT

The First Ministers Health Accords of 2001 through 2003 (Health Canada 2006) launched the renewal of primary care toward more comprehensive care delivery models. We scanned government websites in the 10 Canadian provinces to assess how comprehensive and integrated renewal models were for health and social services in 2018. More comprehensive primary care delivery models were the norm in five out of 10 provinces. The policy approaches were: (1) expanding traditional family practice; (2) creating primary care networks; and (3) increasing the number of community health centres, which provide the broadest range of health and social care. Integration initiatives were limited to medical services. Additional financial and policy investments will be required to meet the comprehensive needs of patients with complex health and social needs at a system level.


Subject(s)
Delivery of Health Care , Primary Health Care , Humans , Canada
6.
Healthc Policy ; 19(SP): 78-87, 2023 10.
Article in English | MEDLINE | ID: mdl-37850707

ABSTRACT

This paper describes 16 Canadian programs designed to provide integrated primary care for older adults. Publicly available data were used to identify the "what" and the "how" of integration for each program. Most programs integrated with other healthcare or medical services (vs. social services). Mechanisms of integration varied; the most common mechanism was interprofessional teams. Only 25% of the programs formally engaged with autonomous physician-led primary care practices (where most Canadians receive their primary care). Findings suggest that integrated care is a priority across Canada but also highlight how far we have to go to achieve both vertical integration within the healthcare sector (primary, secondary and tertiary services) and horizontal integration across sectors (health and social).


Subject(s)
Delivery of Health Care , Independent Living , Humans , Aged , Canada , Social Support
7.
Healthc Policy ; 19(SP): 88-98, 2023 10.
Article in English | MEDLINE | ID: mdl-37850708

ABSTRACT

As healthcare in Canada is provincially operated, the program innovations in one jurisdiction may not be readily known in other jurisdictions. We examine the availability of implementation-specific data for 30 innovative Canadian programs designed to integrate health and social services for patients with complex needs. Using publicly available data and key informant interviews, we were able to populate only ∼50% of our data collection tool (on average). Formal program evaluations were available for only ∼30% of programs. Multiple barriers exist to the compilation and verification of healthcare programs' implementation data across Canada, limiting cross-jurisdictional learning and making a comparison of programs challenging.


Subject(s)
Delivery of Health Care, Integrated , Humans , Canada , Program Evaluation
8.
PLoS One ; 18(6): e0286548, 2023.
Article in English | MEDLINE | ID: mdl-37315078

ABSTRACT

PURPOSE: Unpaid family caregivers provide extensive support for community-dwelling persons living with dementia, impacting family caregivers' health and wellbeing. Further, unpaid family caregiving in rural settings has additional challenges because of lower access to services. This systematic review examines qualitative evidence to summarize the experiences and needs of rural unpaid family caregivers of persons living with dementia. METHODS: CINAHL, SCOPUS, EMBASE, Web of Science, PsychINFO, ProQuest, and Medline were searched for articles investigating the experience and needs of rural family caregivers of persons living with dementia. Eligibility criteria were: 1) original qualitative research; 2) written in the English language; 3) focused on the perspectives of caregivers of community-dwelling persons with dementia; 4) focused on rural settings. Study findings were extracted from each article and a meta-aggregate process was used to synthesize the findings. FINDINGS: Of the 510 articles screened, 36 studies were included in this review. Studies were of moderate to high quality and produced 245 findings that were analyzed to produce three synthesized findings: 1) the challenge of dementia care; 2) rural limitations; 3) rural opportunities. CONCLUSIONS: Rurality is perceived as a limitation for family caregivers in relation to the scope of services provided but can be perceived as a benefit when caregivers experience trustworthy and helpful social networks in rural settings. Implications for practice include establishing and empowering community groups to partner in the provision of care. Further research must be conducted to better understand the strengths and limitations of rurality on caregiving.


Subject(s)
Caregivers , Dementia , Humans , Eligibility Determination , Family Health , Independent Living
9.
Can Fam Physician ; 68(11): 829-835, 2022 11.
Article in English | MEDLINE | ID: mdl-36376035

ABSTRACT

PROBLEM ADDRESSED: While the home-based primary care model offers potential patient and system-level benefits, implementation of interprofessional home-based primary care teams has not been widespread. When caring for homebound patients, family physicians are often not included as regular contributors or participants in the team that coordinates and plans much of the care for these patients. OBJECTIVE OF PROGRAM: To describe a selection of home-based primary care practices and to identify barriers to and facilitators of the creation and sustainability of these models within the publicly funded health care system. PROGRAM DESCRIPTION: Five existing home-based primary care practices were examined: 1 each in Victoria and Vancouver in BC; 1 in Winnipeg, Man; and 2 in Toronto, Ont. The research team conducted semistructured team interviews, interviews with the physician leads, and informal observation of elements of team-based care planning at these 5 sites. From these sources, descriptions of each practice were developed in terms of practice history, context, and initiating factors; practice goals and performance management; and practice design elements, including target population, referral sources, and team composition. A qualitative thematic content analysis was used to extract and distil implementation barriers and facilitators across the 5 practices. Members of each practice team validated the interpretation of thematic information. Substantial heterogeneity was found in the composition of the interprofessional teams. The overarching initiating factor for the home-based component of all practices could be described as identifying and addressing unmet community need. Physician leadership, creative funding models, team camaraderie, and community partnerships were the main facilitators. Limited health system support, geography, and lack of existing models of care were the main barriers. CONCLUSION: Substantial barriers to wider implementation of home-based primary care practices persist. Examination of existing practices identifies the importance of physician leadership and commitment to meeting community need.


Subject(s)
Homebound Persons , Primary Health Care , Humans , Male , Aged , Physicians, Family , Canada , Leadership , Patient Care Team , Qualitative Research
10.
Can Fam Physician ; 68(11): e318-e325, 2022 11.
Article in French | MEDLINE | ID: mdl-36376049

ABSTRACT

PROBLÈME À L'ÉTUDE: Bien que le modèle de prestation de soins primaires à domicile puisse être avantageux tant pour les patients que pour le système, la mise sur pied d'équipes interprofessionnelles offrant ce type de soins n'est pas répandue. Dans le cadre de la prestation des soins aux patients confinés à domicile, les médecins de famille ne font pas souvent partie, que ce soit de façon régulière ou ponctuelle, de l'équipe qui coordonne et planifie la plupart des soins destinés à ces patients. OBJECTIF DU PROGRAMME: Décrire quelques modèles de prestation de soins primaires à domicile et déterminer les obstacles et les facilitateurs relativement à la mise sur pied et à la viabilité de ces modèles dans le système de santé public. DESCRIPTION DU PROGRAMME: Cinq cabinets de prestation de soins primaires à domicile ont fait l'objet d'un examen : 2 en Colombie-Britannique, soit à Victoria et Vancouver; 1 à Winnipeg au Manitoba; et 2 à Toronto en Ontario. L'équipe de recherche a mené à ces 5 sites des entrevues d'équipe semi-structurées, des entretiens avec les médecins dirigeants, de même que des séances d'observation informelles sur les aspects de la planification des soins en équipe. L'information ainsi recueillie a permis d'élaborer une description de chaque cabinet en fonction de l'historique, du contexte et des facteurs déclencheurs liés au modèle; les objectifs et la gestion de la performance; et les éléments conceptuels du cabinet, notamment la population cible, les sources de l'aiguillage et la composition de l'équipe. Une analyse thématique qualitative du contenu a servi à extraire et recenser les obstacles et les facilitateurs de la mise en œuvre à l'échelle des 5 cabinets. Les membres de chaque équipe ont validé l'interprétation de l'information thématique. Une importante hétérogénéité a été observée dans la composition des équipes interprofessionnelles. Le facteur déclencheur déterminant de la prestation des soins à domicile pour chacun des cabinets peut se résumer par la reconnaissance d'un besoin communautaire non comblé. Les principaux facilitateurs étaient le leadership médical, les modèles de financement novateurs, la camaraderie au sein de l'équipe de même que les partenariats communautaires. Les principaux obstacles comprenaient le mince soutien venant du système de santé, l'aspect géographique et l'absence de modèles actuels pour ce type de soins. CONCLUSION: La mise en œuvre élargie des soins primaires à domicile continue de faire face à des obstacles significatifs. L'examen des pratiques en cours permet de relever l'importance du leadership des médecins et de répondre aux besoins de la communauté.


Subject(s)
Home Care Services , Humans , Canada
11.
Int J Integr Care ; 22(1): 25, 2022.
Article in English | MEDLINE | ID: mdl-35431701

ABSTRACT

Introduction: Acute care hospitals often inadequately prepare older adults to transition back to the community. Interventions that seek to improve this transition process are usually evaluated using healthcare use outcomes (e.g., hospital re-visit rates) only, and do not gather provider and patient perspectives about strategies to better integrate care. This protocol describes how we will use complementary research approaches to evaluate an in-hospital sub-acute care (SAC) intervention, designed to better prepare and transition older adults home. Methods: In three sequential research phases, we will assess (1) SAC transition pathways and effectiveness using administrative data, (2) provider fidelity to SAC core practices using chart audits, and (3) SAC implementation outcomes (e.g., facilitators and barriers to success, strategies to better integrate care) using provider and patient interviews. Results: Findings from each phase will be combined to determine SAC effectiveness and efficiency; to assess intervention components and implementation processes that 'work' or require modification; and to identify provider and patient suggestions for improving care integration, both while patients are hospitalized and to some extent after they transition back home. Discussion: This protocol helps to establish a blueprint for comprehensively evaluating interventions conducted in complex care settings using complementary research approaches and data sources.

12.
PLoS One ; 16(11): e0259387, 2021.
Article in English | MEDLINE | ID: mdl-34752475

ABSTRACT

BACKGROUND: Aging in place (AIP) is a policy strategy designed to help older adults remain in their community. While planners internationally have modified aspects of the older adult care continuum (e.g., home care, assisted living, nursing homes) to facilitate AIP, further improvements to community-based supports and services are also required. This study compared and constrasted the community-based factors (e.g., supports, services and personal strategies or characteristics) that family/friend care partners and healthcare stakeholders (i.e., planners/providers) view as most important to help older adults successfully AIP. METHODS: An initial list of factors shown to influence AIP was created from the academic literature. These factors were used to develop a Delphi survey implemented separately on care partners and healthcare stakeholders. Respondents rated the importance of each factor using a 10-point Likert Scale (1 = not important; 10 = absolutely critical). Consensus in each group was defined when at least 80% of participants scored a factor ≥8 ("very important"), with an interquartile range ≤2. Respondents suggested additional factors during Delphi round one. RESULTS: Care partners (N = 25) and healthcare stakeholders (N = 36) completed two and three Delphi rounds, respectively. These groups independently agreed that the following 3 (out of 27) factors were very important to help older adults age in place: keeping one's home safe, maintaining strong inter-personal relationships, and coordinating care across formal providers. While healthcare stakeholders did not reach consensus on other factors, care partners agreed that 7 additional factors (e.g., access to affordable housing, having mental health programs) were important for AIP. CONCLUSIONS: Compared to healthcare stakeholders, care partners felt that more and diverse community-based factors are important to support older adults to successfully AIP. Future research should replicate these findings in other jurisdictions, examine the availability and accessibility of the priority factors, and develop sustainable solutions to enhance their effectiveness.


Subject(s)
Caregivers/psychology , Health Personnel/psychology , Home Care Services , Social Support , Adult , Aged , Delphi Technique , Female , Humans , Independent Living , Interpersonal Relations , Male , Middle Aged
13.
Heliyon ; 7(9): e07895, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34568591

ABSTRACT

Decades of research attempting to slow the onset of Alzheimer's disease (AD) indicates that a better understanding of memory will be key to the discovery of effective therapeutic approaches. Here, we ask whether prodromal neural network dysfunction might occur in the hippocampal trisynaptic circuit by using α5IA (an established memory enhancer and selective negative allosteric modulator of extrasynaptic tonically active α5GABA-A receptors) as a probe drug in TgF344-AD transgenic rats, a model for ß-amyloid induced early onset AD. The results demonstrate that orally bioavailable α5IA increases CA1 pyramidal cell mean firing rates during foraging and peak ripple amplitude during wakeful immobility in wild type F344 rats in a familiar environment. We further demonstrate that CA1 ripples in TgF344-AD rats are nonresponsive to α5IA by 9 months of age, prior to the onset of AD-like pathology and memory dysfunction. TgF344-AD rats express human ß-amyloid precursor protein (with the Swedish mutation) and human presenilin-1 (with a Δ exon 9 mutation) and we found high serum Aß42 and Aß40 levels by 3 months of age. When taken together, this demonstrates, to the best of our knowledge, the first evidence for prodromal α5GABA-A receptor dysfunction in the ripple-generating hippocampal trisynaptic circuit of AD-like transgenic rats. As α5GABA-A receptors are found at extrasynaptic and synaptic contacts, we posit that negative modulation of α5GABA-A receptor mediated tonic as well as phasic inhibition augments CA1 ripples and memory consolidation but that this modulatory mechanism is lost at an early stage of AD onset.

14.
Int J Aging Hum Dev ; 93(1): 543-561, 2021 07.
Article in English | MEDLINE | ID: mdl-32354222

ABSTRACT

Self-perceptions of aging (SPA) refer to attitudes about one's aging process and are linked to physical health and longevity. How SPA correlates with cognitive function in older adulthood is less well known. 136 older adults were administered a multifaceted SPA measure, The Brief Ageing Perceptions Questionnaire (B-APQ), in addition to a demographic form and a comprehensive neuropsychological battery. Positive and negative subscales of the B-APQ were correlated with aspects of cognitive function. Regression analyses revealed that only the positive B-APQ subscales predicted mental status (ß = .19, p < .05), short-delay memory (ß = .16, p < .05), processing speed (ß = -.21, p < .05), and two measures of executive function (ß = -.21, p < .01; ß = .18, p < .05). This is the first study to demonstrate that positive dimensions of SPA relate to cognitive function in older adulthood.


Subject(s)
Aging/psychology , Cognition , Optimism/psychology , Self Concept , Aged , Cognitive Aging/psychology , Executive Function , Female , Humans , Male , Mental Recall , Neuropsychological Tests , Surveys and Questionnaires
15.
Clin Transplant ; 34(9): e14017, 2020 09.
Article in English | MEDLINE | ID: mdl-32573816

ABSTRACT

BACKGROUND: Frailty and decreased functional status are risk factors for adverse kidney transplant (KT) outcomes. Our objective was to examine the efficacy of an exercise intervention on frailty and decreased functional status in a cohort of patients with advanced chronic kidney disease (CKD). METHODS: We conducted a prospective study involving 21 adults with ≥stage 4 CKD who were (a) frail or pre-frail by Fried phenotype and/or (b) had lower extremity impairment [short physical performance battery score ≤10]. The intervention consisted of two supervised outpatient exercise sessions per week for 8 weeks. RESULTS: Among our cohort, median participant age was 62 years (interquartile range, 53-67) and 85.7% had been evaluated for KT. Following the study, participants reported satisfaction with the intervention and multiple frailty parameters improved significantly, including fatigue, physical activity, walking time, and grip strength. Lower extremity impairment also improved (90.5%-61.9%, P = .03). No study-related adverse events occurred. CONCLUSIONS: Preliminary data from this study suggest that a supervised, outpatient exercise intervention is safe, acceptable, feasible, and associated with improved frailty parameters, and lower extremity function, in patients with advanced CKD. Further studies are needed to confirm these findings and determine whether this prehabilitation strategy improves KT outcomes.


Subject(s)
Frailty , Kidney Transplantation , Adult , Exercise , Humans , Lower Extremity , Middle Aged , Preoperative Exercise , Prospective Studies
16.
Ecol Evol ; 8(16): 8115-8125, 2018 Aug.
Article in English | MEDLINE | ID: mdl-30250688

ABSTRACT

Sea-level rise (SLR) impacts on intertidal habitat depend on coastal topology, accretion, and constraints from surrounding development. Such habitat changes might affect species like Belding's savannah sparrows (Passerculus sandwichensis beldingi; BSSP), which live in high-elevation salt marsh in the Southern California Bight. To predict how BSSP habitat might change under various SLR scenarios, we first constructed a suitability model by matching bird observations with elevation. We then mapped current BSSP breeding and foraging habitat at six estuarine sites by applying the elevation-suitability model to digital elevation models. To estimate changes in digital elevation models under different SLR scenarios, we used a site-specific, one-dimensional elevation model (wetland accretion rate model of ecosystem resilience). We then applied our elevation-suitability model to the projected digital elevation models. The resulting maps suggest that suitable breeding and foraging habitat could decline as increased inundation converts middle- and high-elevation suitable habitat to mudflat and subtidal zones. As a result, the highest SLR scenario predicted that no suitable breeding or foraging habitat would remain at any site by 2100 and 2110. Removing development constraints to facilitate landward migration of high salt marsh, or redistributing dredge spoils to replace submerged habitat, might create future high salt marsh habitat, thereby reducing extirpation risk for BSSP in southern California.

17.
Funct Ecol ; 31(12): 2263-2273, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29398763

ABSTRACT

Early-life adversity can have long-lasting effects on physiological, behavioural, cognitive, and somatic processes. Consequently, these effects may alter an organism's life-history strategy and reproductive tactics.In response to early-life immune activation, we quantified levels of the acute phase protein haptoglobin (Hp) during development in male zebra finches (Taeniopygia guttata). Then, we examined the long-term impacts of early-life immune activation on an important static sexual signal, song complexity, as well as effects of early-life immune activation on the relationship between song complexity and a dynamic sexual signal, beak colouration. Finally, we performed mate-choice trials to determine if male early-life experience impacted female preference.Challenge with keyhole limpet hemocyanin (KLH) resulted in increased song complexity compared to lipopolysaccharide (LPS) treatment or the control. Hp levels were inversely correlated with song complexity. Moreover, KLH-treatment resulted in negative associations between the two sexual signals (beak colouration and song complexity). Females demonstrated some preference for KLH-treated males over controls and for control males over LPS-treated males in mate choice trials.Developmental immune activation has variable effects on the expression of secondary sexual traits in adulthood, including enhancing the expression of some traits. Because developmental levels of Hp and adult song complexity were correlated, future studies should explore a potential role for exposure to inflammation during development on song learning.Early-life adversity may differentially impact static versus dynamic signals. The use of phenotypic correlations can be a powerful tool for examining the impact of early-life experience on the associations among different traits, including sexual signals.

18.
J Health Psychol ; 21(1): 40-9, 2016 Jan.
Article in English | MEDLINE | ID: mdl-24567303

ABSTRACT

This study assessed the extent to which older adults attribute a recent heart attack/stroke to "old age," and examined consequences for subsequent lifestyle behavior and health-care service utilization. Community-dwelling adults (N = 57, ages 73-98 years) were interviewed about their heart attack/stroke, and an objective health registry provided data on health-care utilization over a 3-year period. Endorsement of "old age" as a cause of heart attack/stroke negatively predicted lifestyle behavior change, and positively predicted frequency of physician visits and likelihood of hospitalization over the subsequent 3 years. Findings suggest the importance of considering "old age" attributions in the context of cardiovascular health events.


Subject(s)
Aging/physiology , Health Behavior , Myocardial Infarction/etiology , Stroke/etiology , Age Factors , Aged , Aged, 80 and over , Aging/psychology , Female , Hospitalization/statistics & numerical data , Humans , Life Style , Male , Risk Factors
19.
Psychol Health ; 30(11): 1326-45, 2015.
Article in English | MEDLINE | ID: mdl-25978418

ABSTRACT

Developmental transitions are experienced throughout the life course and necessitate adapting to consequential and unpredictable changes that can undermine health. Our six-month study (n = 239) explored whether selective secondary control striving (motivation-focused thinking) protects against the elevated levels of stress and depressive symptoms increasingly common to young adults navigating the challenging school-to-university transition. Path analyses supplemented with tests of moderated mediation revealed that, for young adults who face challenging obstacles to goal attainment, selective secondary control indirectly reduced long-term stress-related physical and depressive symptoms through selective primary control and previously unexamined measures of discrete emotions. Results advance the existing literature by demonstrating that (a) selective secondary control has health benefits for vulnerable young adults and (b) these benefits are largely a consequence of the process variables proposed in Heckhausen et al.'s (2010) theory.


Subject(s)
Depression/prevention & control , Motivation , Stress, Psychological/prevention & control , Thinking , Adaptation, Psychological , Adolescent , Depression/psychology , Female , Humans , Male , Protective Factors , Schools , Stress, Psychological/complications , Stress, Psychological/psychology , Universities , Young Adult
20.
Hippocampus ; 25(12): 1541-55, 2015 Dec.
Article in English | MEDLINE | ID: mdl-25941121

ABSTRACT

Learning and memory deficits associated with age-related mild cognitive impairment have long been attributed to impaired processing within the hippocampus. Hyperactivity within the hippocampal CA3 region that is associated with aging is mediated in part by a loss of functional inhibitory interneurons and thought to underlie impaired performance in spatial memory tasks, including the abnormal tendency in aged animals to pattern complete spatial representations. Here, we asked whether the spatial firing patterns of simultaneously recorded CA3 and CA1 neurons in young and aged rats could be manipulated pharmacologically to selectively reduce CA3 hyperactivity and thus, according to hypothesis, the associated abnormality in spatial representations. We used chronically implanted high-density tetrodes to record the spatial firing properties of CA3 and CA1 units during animal exploration for food in familiar and novel environments. Aged CA3 place cells have higher firing rates, larger place fields, less spatial information content, and respond less to a change from a familiar to a novel environment than young CA3 cells. We also find that the combination of levetiracetam (LEV) + valproic acid (VPA), previously shown to act as a cognitive enhancer in tests of spatial memory, attenuate CA3 place cell firing rates, reduce place field area, and increase spatial information content in aged but not young adult rats. This is consistent with drug enhancing the specificity of neuronal firing with respect to spatial location. Contrary to expectation, however, LEV + VPA reduces place cell discrimination between novel and familiar environments, i.e., spatial correlations increase, independent of age even though drug enhances performance in cognitive tasks. The results demonstrate that spatial information content, or the number of bits of information encoded per action potential, may be the key correlate for enhancement of spatial memory by LEV + VPA.


Subject(s)
Aging/drug effects , CA3 Region, Hippocampal/drug effects , Central Nervous System Agents/administration & dosage , Piracetam/analogs & derivatives , Space Perception/drug effects , Valproic Acid/administration & dosage , Action Potentials/drug effects , Action Potentials/physiology , Aging/physiology , Animals , CA1 Region, Hippocampal/drug effects , CA1 Region, Hippocampal/physiology , CA3 Region, Hippocampal/physiology , Discrimination, Psychological/drug effects , Discrimination, Psychological/physiology , Drug Synergism , Exploratory Behavior/drug effects , Exploratory Behavior/physiology , Levetiracetam , Male , Maze Learning/drug effects , Maze Learning/physiology , Neurons/drug effects , Neurons/physiology , Piracetam/administration & dosage , Rats, Long-Evans , Space Perception/physiology , Spatial Memory/drug effects , Spatial Memory/physiology
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