Neurogenesis Drives Stimulus Decorrelation in a Model of the Olfactory Bulb

The reshaping and decorrelation of similar activity patterns by neuronal networks can enhance their discriminability, storage, and retrieval. How can such networks learn to decorrelate new complex patterns, as they arise in the olfactory system? Using a computational network model for the dominant neural populations of the olfactory bulb we show that fundamental aspects of the adult neurogenesis observed in the olfactory bulb -- the persistent addition of new inhibitory granule cells to the network, their activity-dependent survival, and the reciprocal character of their synapses with the principal mitral cells -- are sufficient to restructure the network and to alter its encoding of odor stimuli adaptively so as to reduce the correlations between the bulbar representations of similar stimuli. The decorrelation is quite robust with respect to various types of perturbations of the reciprocity. The model parsimoniously captures the experimentally observed role of neurogenesis in perceptual learning and the enhanced response of young granule cells to novel stimuli. Moreover, it makes specific predictions for the type of odor enrichment that should be effective in enhancing the ability of animals to discriminate similar odor mixtures

Regulation of Spike Timing-Dependent Plasticity of Olfactory Inputs in Mitral Cells in the Rat Olfactory Bulb

The recent history of activity input onto granule cells (GCs) in the main olfactory bulb can affect the strength of lateral inhibition, which functions to generate contrast enhancement. However, at the plasticity level, it is unknown whether and how the prior modification of lateral inhibition modulates the subsequent induction of long-lasting changes of the excitatory olfactory nerve (ON) inputs to mitral cells (MCs). Here we found that the repetitive stimulation of two distinct excitatory inputs to the GCs induced a persistent modification of lateral inhibition in MCs in opposing directions. This bidirectional modification of inhibitory inputs differentially regulated the subsequent synaptic plasticity of the excitatory ON inputs to the MCs, which was induced by the repetitive pairing of excitatory postsynaptic potentials (EPSPs) with postsynaptic bursts. The regulation of spike timing-dependent plasticity (STDP) was achieved by the regulation of the inter-spike-interval (ISI) of the postsynaptic bursts. This novel form of inhibition-dependent regulation of plasticity may contribute to the encoding or processing of olfactory information in the olfactory bulb

Delay in seeking health care for acute coronary syndromes in a Lebanese sample

Early treatment of patients with acute coronary syndromes (ACS) is crucial to reduce morbidity and mortality. The purpose of this study was to examine delay in seeking care for ACS symptoms in a Lebanese sample and identify predictors of delay. Medical record reviews and interviews using the Response to Symptoms Questionnaire were conducted with 204 ACS patients in coronary care within 72 hours of admission. Median time from symptom onset to hospital arrival was 4.5 hours. Higher education, presence of dyspnea, intermittent symptoms, and waiting for symptoms to go away predicted longer delays, whereas intensity of symptoms and active response (going to the hospital) predicted shorter delays. The findings suggest lack of knowledge of ACS symptoms and the need for public education in this regard. © 2006 Sage Publications.Al-Hassan Musa A, 2005, Int J Nurs Pract, V11, P13, DOI 10.1111-j.1440-172X.2005.00497.x; ALONZO AA, 1986, SOC SCI MED, V22, P1297, DOI 10.1016-0277-9536(86)90093-6; Ashton K C, 1999, Prog Cardiovasc Nurs, V14, P53; Berton G, 2001, Ital Heart J, V2, P766; Braunwald E, 2000, J AM COLL CARDIOL, V36, P970, DOI 10.1016-S0735-1097(00)00889-5; Braunwald E, 2002, J AM COLL CARDIOL, V40, P1366, DOI 10.1016-S0735-1097(02)02336-7; Brown AL, 2000, CIRCULATION, V102, P173; BURNETT RE, 1995, AM J CARDIOL, V75, P1019, DOI 10.1016-S0002-9149(99)80716-4; Canto JG, 2000, JAMA-J AM MED ASSOC, V283, P3223, DOI 10.1001-jama.283.24.3223; Diefenbach MA, 1996, J SOC DISTRESS HOMEL, V5, P11, DOI 10.1007-BF02090456; Dracup K, 1997, HEART LUNG, V26, P253, DOI 10.1016-S0147-9563(97)90082-0; DRACUP K, 1995, SOC SCI MED, V40, P379, DOI 10.1016-0277-9536(94)00278-2; Dracup K, 2003, J NURS SCHOLARSHIP, V35, P317, DOI 10.1111-j.1547-5069.2003.00317.x; Finnegan JR, 2000, PREV MED, V31, P205, DOI 10.1006-pmed.2000.0702; FRANZOSI MG, 1995, ARCH INTERN MED, V155, P1481; Gurwitz JH, 1997, ANN INTERN MED, V126, P593; Ho PM, 2002, ANN EMERG MED, V40, P381, DOI 10.1067-mem.2002.125717; Johansson I, 2004, HEART LUNG, V33, P291, DOI 10.1016-j.hrtlng.2004.04.002; Kentsch M, 2002, Z KARDIOL, V91, P147; KENYON LW, 1991, CIRCULATION, V84, P1969; KULWICKI AD, 2003, TRANSCULTURAL HLTH C, P90; Lee H, 2000, APPL NURS RES, V13, P125, DOI 10.1053-apnr.2000.7652; LEITCH JW, 1989, MED J AUSTRALIA, V150, P6; Leslie WS, 2000, HEART, V84, P137, DOI 10.1136-heart.84.2.137; McKinley S, 2000, HEART LUNG, V29, P237, DOI 10.1067-mhl.2000.106940; HAND MM, 1994, ANN EMERG MED, V23, P311; Nawfal H, 2004, RESIDENT ISSUES LEBA; Reilly A, 1994, Am J Crit Care, V3, P300; Sawaya JI, 2000, LEBAN MED J, V48, P63; Sawaya J I, 1999, J Med Liban, V47, P2; SCHROEDER JS, 1978, AM J MED, V64, P742, DOI 10.1016-0002-9343(78)90512-0; SIMOONS ML, 1986, J AM COLL CARDIOL, V7, P717; Smith SC, 2001, CIRCULATION, V103, P3019; Wu Y, 2004, CHINESE MED J-PEKING, V117, P1772; Zerwic JJ, 2003, NURS RES, V52, P159, DOI 10.1097-00006199-200305000-0000517151

Perceptions of precision medicine among diverse dementia caregivers and professional providers

Abstract Introduction Underrepresented groups experience health disparities and a history of exploitation by researchers and the health‐care system that may contribute to distrust of new treatments and technologies. This study aims to understand how diverse family caregivers and health‐care professionals view the benefits and risks of precision medicine as well as cultural dimensions to consider when developing and implementing precision medicine interventions in dementia care. Methods Eight focus group sessions and one individual interview were conducted over a 6‐month period. Fifty‐four focus group participants included African‐American, American Indian, rural Caucasian, Latino, and West African caregivers and health professionals. The majority of participants were female (73%) and were of Hispanic/Latino ethnicity (68%). About a third of participants identified their race as white. Participants were presented with four hypothetical scenarios related to precision medicine diagnostic and treatment approaches in dementia care: (1) genetic testing for dementia risk, (2) health‐care informatics to determine individualized medication dosages based on health and family history, (3) a smartphone application providing dementia caregiving tips, and (4) remote activity monitoring technology in the home. Focus groups' responses were coded using thematic analysis. Results Participants indicated skepticism regarding the use of precision medicine in their communities. Concerns included cost of precision medicine and insurance coverage; lack of alignment with cultural norms; fraught relationships between communities, health professionals, and researchers; data ownership and privacy; and the trade‐off between knowing risk and treatment benefit. Discussion Establishing relationships with underserved communities is crucial to advancing precision medicine in dementia care. Appropriate engagement with diverse racial, ethnic, and geographic communities may require significant investment but is necessary to deliver precision medicine effectively

Development and Open Trial of a Technology-Enhanced Family Intervention for Adolescents at Risk for Mood Disorders

AimIntegrating psychosocial interventions with mobile apps may increase treatment engagement among adolescents. We examined the user experience, uptake, and clinical effects of a mobile-enhanced family-focused therapy (FFT) among adolescents at risk for mood disorders.MethodWe created a mobile app containing 12 lesson plans corresponding to content of weekly FFT sessions, with modules concerning mood management, family communication and problem-solving. We pilot tested the app in an open trial of FFT (12 sessions in 18 weeks) for adolescents who had active depressive or hypomanic symptoms, a parent with mood disorder, and at least one parent who expressed high levels of criticism. Teens and parents made daily and weekly ratings of youths' moods, amount of parent/offspring criticism, and practice of FFT psychoeducational, communication or problem-solving skills. Independent evaluators interviewed adolescents at baseline and every 9 weeks over 27 weeks to measure symptom trajectories.ResultsParticipants were adolescents (n=22; mean age 15.4 ± 1.8 years; 45.5% female) and their 34 parents. Completion of requested app assessment and skill practices averaged 46%-65% among adolescents and parents over 18 weeks of treatment. Adolescents showed significant improvement in clinician-rated depression scores over 27 weeks (Cohen's d=1.58, 95% CI, 0.83 to 2.32) and reported reductions in the amount of perceived criticism expressed by parents.LimitationsThe uncontrolled design limits inferences about whether the mobile app augmented the effects of FFT on moods or family relationships.ConclusionsMobile applications may enhance users' responses to family therapy and provide clinicians with information regarding clinical status. Clinicaltrials.gov NCT03913013