1,376 research outputs found
Acetylcholine release in mouse hippocampal CA1 preferentially activates inhibitory-selective interneurons via α4β2* nicotinic receptor activation
Acetylcholine (ACh) release onto nicotinic receptors directly activates subsets of inhibitory interneurons in hippocampal CA1. However, the specific interneurons activated and their effect on the hippocampal network is not completely understood. Therefore, we investigated subsets of hippocampal CA1 interneurons that respond to ACh release through the activation of nicotinic receptors and the potential downstream effects this may have on hippocampal CA1 network function. ACh was optogenetically released in mouse hippocampal slices by expressing the excitatory optogenetic protein oChIEF-tdTomato in medial septum/diagonal band of Broca cholinergic neurons using Cre recombinase-dependent adeno-associated viral mediated transfection. The actions of optogenetically released ACh were assessed on both pyramidal neurons and different interneuron subtypes via whole cell patch clamp methods. Vasoactive intestinal peptide (VIP)-expressing interneurons that selectively innervate other interneurons (VIP/IS) were excited by ACh through the activation of nicotinic receptors containing α4 and β2 subunits (α4β2*). ACh release onto VIP/IS was presynaptically inhibited by M2 muscarinic autoreceptors. ACh release produced spontaneous inhibitory postsynaptic current (sIPSC) barrages blocked by dihydro-β-erythroidine in interneurons but not pyramidal neurons. Optogenetic suppression of VIP interneurons did not inhibit these sIPSC barrages suggesting other interneuron-selective interneurons were also excited by α4β2* nicotinic receptor activation. In contrast, interneurons that innervate pyramidal neuron perisomatic regions were not activated by ACh release onto nicotinic receptors. Therefore, we propose ACh release in CA1 facilitates disinhibition through activation of α4β2* nicotinic receptors on interneuron-selective interneurons whereas interneurons that innervate pyramidal neurons are less affected by nicotinic receptor activation
Recommended from our members
The Neuropsychological Profiles of Mild Alzheimer's Disease and Questionable Dementia as Compared to Age-Related Cognitive Decline
Test scores from a comprehensive neuropsychological battery administered to 1602 subjects consisting of 1347 subjects with probable Alzheimer's disease (AD), 100 subjects with questionable dementia (QD) and 155 non-demented elderly control subjects were cross-sectionally analyzed. Subjects with probable AD were categorized as mild (n = 244), moderate (n = 480), severe (n = 376), and very severe (n = 247) according to modified mini mental status exam (mMMSE) scores. Mean scores on individual neuropsychological tests are provided for each group of subjects. Stratified random sampling was performed to select a sample of mild AD subjects who were matched in age and education to non-demented elderly controls, and analyses focused on the performance of QD subjects and mild AD subjects, whose scores were compared to those of the elderly control subjects. Selected scores were organized by cognitive domain and logistic regressions were used to determine the domains and individual tests within each that were most predictive of group status. Results suggested a profile of scores associated with QD and mild AD including impaired recall of verbal information for both groups. Areas of lower functioning in QD subjects as compared to elderly controls included category fluency and visuospatial ability
Strengthening Knowledge Co-Production Capacity: Examining Interest in Community-University Partnerships.
Building successful, enduring research partnerships is essential for improving links between knowledge and action to address sustainability challenges. Communication research can play a critical role in fostering more effective research partnerships, especially those concerned with knowledge co-production processes. This article focuses on community-university research partnerships and factors that influence participation in the co-production process. We identify specific pathways for improving partnership development through a prospective analytical approach that examines community officials’ interest in partnering with university researchers. Using survey responses from a statewide sample of Maine municipal officials, we conduct a statistical analysis of community-university partnership potential to test a conceptual model of partnership interest grounded in natural resource management theory and environmental communication. Our findings both support and advance prior research on collaborations. Results reveal that belief in the helpfulness of the collaborator to solve problems, institutional proximity, familiarity, perceived problem severity and problem type and trust influence interest in developing community-university partnerships. These findings underscore the benefits of proactively assessing partnership potential prior to forming partnerships and the important roles for communication research within sustainability science, especially with regard to strengthening partnership formation and knowledge co-production processes
Survey of University of California Academics\u27 Attitudes Regarding the Impact of Escaped Horticultural Introductions on Wildlands
In order to investigate whether there were differences in attitudes and perceptions within the University of California regarding the impact of introduced ornamental plants, we conducted a survey of academics with assignments in natural resource programs or ornamental horticulture. In general, the ornamental horticulture academics did not view the problem of invasive species as severely as the natural resource academics, but the both groups recognize that non-native landscape ornamentals now occur and can affect California\u27s wildlands. These data can be used to provide training to academics on this issue and help facilitate discussion between the different groups
An opportunistic sighting of a flock of Black Petrels (Procellaria parkinsoni) at the Galapagos Islands, Ecuador
Recommended from our members
Impairment of Nonverbal Recognition in Alzheimer Disease: A Pet O-15 Study
OBJECTIVE: To characterize deficits in nonverbal recognition memory and functional brain changes associated with these deficits in Alzheimer disease (AD). METHODS: Using O-15 PET, we studied 11 patients with AD and 17 cognitively intact elders during the combined encoding and retrieval periods of a nonverbal recognition task. Both task conditions involved recognition of line drawings of abstract shapes. In both conditions, subjects were first presented a list of shapes as study items, and then a list as test items, containing items from the study list and foils. In the titrated demand condition, the shape study list size (SLS) was adjusted prior to imaging so that each subject performed at approximately 75% recognition accuracy; difficulty during PET scanning in this condition was approximately matched across subjects. A control task was used in which SLS = 1 shape. RESULTS: During performance of the titrated demand condition, SLS averaged 4.55 (+/-1.86) shapes for patients with AD and 7.53 (+/-4.81) for healthy elderly subjects (p = 0.031). However, both groups of subjects were closely matched on performance in the titrated demand condition during PET scanning with 72.17% (+/-7.98%) correct for patients with AD and 72.25% (+/-7.03%) for elders (p = 0.979). PET results demonstrated that patients with AD showed greater mean differences between the titrated demand condition and control in areas including the left fusiform and inferior frontal regions (Brodmann areas 19 and 45). CONCLUSIONS: Relative fusiform and inferior frontal differences may reflect the Alzheimer disease (AD) patients' compensatory engagement of alternate brain regions. The strategy used by patients with AD is likely to be a general mechanism of compensation, rather than task-specific
Recommended from our members
Neurologic Signs and Symptoms in a Cohort of Homosexual Men Followed for 4.5 Years
We traced the development of neurologic impairment in 207 homosexual men (123 human immunodeficiency virus [HIV]-positive and 84 HIV-negative controls) over 4.5 years of follow-up. We applied generalized estimating equations to logistic regression analyses with repeated measures to examine the differences between HIV-positive and HIV-negative subjects with respect to the likelihood of developing six neurologic outcomes derived from a factor analysis, significant neurologic impairment (modified Kurtzke disability score of ≥3), or significant neuropsycholog-ical impairment. We found that, over time, HIV-positive subjects were more likely to develop clinically significant ex-trapyramidal signs and frontal release signs than HIV-negative subjects. Controlling for age or education, as CD4 count declined, the odds of developing significant extrapyramidal signs, abnormalities in alternating movements, frontal release signs, and a Kurtzke score ≥3 increased. HIV-positive subjects were almost five times as likely (odds ratio [OR], 4.6; 95% CI, 1.6 to 13.4) as HIV-negative subjects to stay the same or worsen neurologically on the next visit, and those with CD4 ≥200 were 4.8 times as likely (OR, 4.8; 95% CI, 2.2 to 10.7) to maintain or worsen neurologically relative to those with higher CD4 counts. We conclude that neurologic impairment becomes increasingly apparent over time in HIV-infected men, especially in those with low CD4 counts
Recommended from our members
Cognitive Test Performance among Nondemented Elderly African Americans and Whites
We examined the neuropsychological test performance of a randomly selected community sample of English-speaking non-Hispanic African American and white elders in northern Manhattan. All participants were diagnosed as nondemented by a neurologist, whose assessment was made independent of neuropsychological test scores. African American elders obtained significantly lower scores on measures of verbal and nonverbal learning and memory, abstract reasoning, language, and visuospatial skill than whites. After using a stratified random sampling technique to match groups on years of education, many of the discrepancies became nonsignificant; however, significant ethnic group differences on measures of figure memory, verbal abstraction, category fluency, and visuospatial skill remained. Discrepancies in test performance of education-matched African Americans and whites could not be accounted for by occupational attainment or history of medical conditions such as hypertension and diabetes. These findings emphasize the importance of using culturally appropriate norms when evaluating ethnically diverse elderly for dementia
Advances in theory and their application within the field of zeolite chemistry
Zeolites are versatile and fascinating materials which are vital for a wide range of industries, due to their unique structural and chemical properties, which are the basis of applications in gas separation, ion exchange and catalysis. Given their economic impact, there is a powerful incentive for smart design of new materials with enhanced functionalities to obtain the best material for a given application. Over the last decades, theoretical modeling has matured to a level that model guided design has become within reach. Major hurdles have been overcome to reach this point and almost all contemporary methods in computational materials chemistry are actively used in the field of modeling zeolite chemistry and applications. Integration of complementary modeling approaches is necessary to obtain reliable predictions and rationalizations from theory. A close synergy between experimentalists and theoreticians has led to a deep understanding of the complexity of the system at hand, but also allowed the identification of shortcomings in current theoretical approaches. Inspired by the importance of zeolite characterization which can now be performed at the single atom and single molecule level from experiment, computational spectroscopy has grown in importance in the last decade. In this review most of the currently available modeling tools are introduced and illustrated on the most challenging problems in zeolite science. Directions for future model developments will be given
- …