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PubMed2006

Contribution of a single CA3 neuron to network synchrony.

Oscillations at theta (3-8 Hz) and gamma (30-80 Hz) frequencies co-occur during arousal, exploration, and rapid eye movement sleep and relate to information processing underlying learning and memory within neuronal networks. In hippocampus, gamma and theta frequency oscillations are associated with modification of synaptic weights, spatial learning, and short-term memory. These oscillations are referred to as network phenomena and, thereby, the role of single neuron oscillations in the generation of neuronal networks remains unclear. We report that an individual CA3 pyramidal cell can activate the CA1 neuronal network in vivo in rat hippocampus using electrical stimulations with simultaneous intracellular gamma and extracellular theta and slow (0.5-1 Hz) frequencies. These results suggest that an individual pyramidal cell can contribute to self-organization of a neuronal small-scale network.

Animals↗

PubMed2004

Distributions of two chicken bombesin receptors, bombesin receptor subtype-3.5 (chBRS-3.5) and gastrin-releasing peptide receptor (chGRP-R) mRNAS in the chicken telencephalon.

Bombesin (BN)-like peptide receptors are known to be essential to the regulation of not only homeostasis, including feeding behavior, but also of emotional systems in mammal. Recently, two novel BN receptors, chicken BN-like peptide receptor subtype-3.5 (chBRS-3.5) and gastrin-releasing peptide receptor (chGRP-R), have been identified. Here, we report the localizations of these receptors' mRNAs in the chick brain through development using in situ hybridization. First, chBRS-3.5 mRNA signals were found in the dorsal ventricular ridge at embryonic day (ED) 9. Strong signals were observed in the hyperpallium accessorium, nidopallium and nucleus basorostralis pallii, and moderate signals were found in the hippocampus, cortex piriformis, hyperpallium intercalatum, area temporo-parieto-occipitalis, nucleus striae terminalis lateralis, nucleus olfactorius anterior and organum septi lateralis at ED16. This wide expression in the pallium persisted during posthatch periods. Abundant expressions in the hyperpallium, nidopallium, considered to be similar to the mammalian cortex, as well as in the hippocampus, indicate participation of these molecules in the processing of sensory information, motor function, learning and memory. Telencephalic areas devoid of chBRS-3.5 signals were the entopallium, arcopallium anterius, globus pallidus, nucleus intrapeduncularis, tuberculum olfactorius, nucleus septalis lateralis, hypothalamic and thalamic areas. In contrast to chBRS-3.5, chGRP-R mRNA signals were found in the pallidum at ED5 and 9. At ED16, chGRP-R mRNA signals were localized in the medial striatum and hypothalamus. GRP-R expression in the hypothalamic region was phylogenically conserved. Thus, chBRS-3.5 mRNA signals were distributed in a broader region and were more intense than chGRP-R mRNA. Taken together, chGRP-R and chBRS-3.5 mRNA occurred in similar regions of mammals that express GRP-R. BN/GRP-immunoreactive neurons and varicosities were found mainly in the pallium, especially in the hyperpallium accessorium and nidopallium, and this distribution coincided with that of chBRS-3.5 mRNA. This result suggests that the endogenous ligands for chBRS-3.5 were likely BN-like peptides produced in the pallium.

Animals↗

PubMed2004

A comparison of neuronal reactions during classical and instrumental conditioning under similar conditions.

During the elaboration of an instrumental reflex, it is not obligatory to use a conditioned stimulus, which signals the necessity to generate an instrumental reaction in order to receive reinforcement. However, the presence of a conditioned stimulus simplifies analysis of instrumental reaction, which in this case is the response to the conditioned stimulus. On the other hand, it is necessary to distinguish between instrumental and classical conditioning, since in both cases the response to a conditioned stimulus increases. We studied neuronal analogs of classical and instrumental conditioning in the identified neurons responsible for the defensive closure of the pneumostome in the Helix mollusk under the same conditions. During classical conditioning, a mollusk received punishment after a tactile stimulus. During instrumental conditioning, a mollusk received punishment when an identified neuron did not generate an action potential in response to a tactile stimulus. The appearance of a painful stimulus did not depend on the generation or failure of a spike in the related control neuron. Another tactile stimulus, which was never paired with an unconditioned stimulus, was used as a discriminated stimulus. We also compared the behavior of such identified neurons during pseudoconditioning. The experiments were carried out in a semi-intact preparation. We examined how responses to the tactile and painful stimuli changed during different forms of training. It was shown that the dynamics of neuronal responses to a conditioned tactile stimulus were much more complex during instrumental conditioning and consisted of several phases. Throughout a learning session, neural system consecutively acquired information as to which kind of learning was presented, whether a reaction of the neural system must be generated or inhibited and which instrumental reaction is correct. We have demonstrated that response to a painful stimulus during classical conditioning decreases after short-term initial increase. However, during instrumental learning, the neurons controlling instrumental action remained highly sensitive to the unconditioned stimulus. Meanwhile, foreign neurons decreased their responses to the unconditioned stimulus. We may tentatively conclude that classical and instrumental paradigms are fundamentally different at the cellular level.

Action Potentials↗

PubMedDate not supplied

Critical thinking and patient outcomes: a review.

There has been a multidisciplinary plethora of critical thinking definitions stemming from educators in 1912 1 through and inclusive of today. As nurses' roles change in response to the dynamics of managed care and an increase in use of biotechnology in health care, more is expected of them both in terms of psychomotor and cognitive skills. The American Association for Colleges of Nursing requires that critical thinking be reflected within academic nursing programs as a core competency for program accreditation. 2 Although critical thinking has been associated with and evaluated in regard to learning outcomes, little information exists which links critical thinking to patient outcomes. The purpose of this article is to provide a literature review of critical thinking and to explore a possible link between nurses' critical thinking and patient outcomes.

Accreditation↗

PubMed2005

Levels of processing effects on recognition memory in patients with schizophrenia.

This study sought to characterize the performance of patients with schizophrenia, as compared with healthy participants, on a memory task that required encoding of items to different depths. Participants included 21 individuals with schizophrenia and 26 healthy controls. During the encoding phase of the study, participants processed successively presented words in two ways: perceptually (by making a decision as to whether the letter "a" was present in the word) or semantically (by making a living/nonliving decision for each word). During the recognition phase of the study, participants were presented with a list of words containing items that had been presented during the encoding phase (during either the letter decision task or the semantic decision task), as well as items that had not been seen before (foils). Though patients with schizophrenia performed more poorly overall on the recognition task, recognition was facilitated by semantic encoding to an equivalent degree in both groups. In other words, while significant main effects were present for group and encoding, no groupxencoding condition was present. This result is consistent with previous findings of a lack of qualitative differences in performance on learning and memory tasks between patients with schizophrenia and healthy controls. It also suggests that strategies that place constraints on the encoding processes used by patients may help improve the efficiency with which they learn and remember information.

Adult↗

PubMed2026

Development and validation of a serum peptidomic signature for early detection of asymptomatic ovarian cancer: A multi-center prospective study.

Early detection of asymptomatic ovarian cancer (asym-OC) remains a critical challenge, the failure of which underlies its high mortality. Performing serum peptidomic profiling of 843 participants in the cohort SOCFCP, we distill 1,081 initial features into a 7-marker panel for asym-OC detection via a biology-informed machine-learning (ML)-based feature selection strategy. Three markers significantly revert toward non-OC levels after surgery. Integrating the panel with age, CA125, and HE4, we develop and externally validate (n = 159) a LightGBM model, ProMS+. For early-stage OC detection, ProMS+ shows a specificity of 92.6% at 95.0% sensitivity, outperforming CA125 (44.7%), HE4 (11.2%), and Risk of Ovarian Malignancy Algorithm (ROMA) (24.0%), with an area under the curve (AUC) of 0.993. In a simulated high-risk population (n = 100,000; OC prevalence = 1%), ProMS+ yields a high AUC (0.983) and a higher positive predictive value than CA125, HE4, and Age + CA125 + HE4 combined model (0.201 vs. 0.027, 0.090, and 0.064). ProMS+ offers a promising, non-invasive, and interpretable approach for the early detection of asym-OC.

Humans↗

PubMed1990

Knowledge-based prediction of protein structures.

We propose a knowledge-based approach to the prediction of protein structures in cases where there is no sequence-homology to proteins with known spatial structure. Using methods from Artificial Intelligence we attempt to take into account long-range interactions within the prediction process. This allows not only the assignment of secondary but also of supersecondary structure elements. In particular, the patterns used as conditions of prediction rules are generated by learning methods from information contained in the Protein Data Base. Patterns on higher levels of the protein structure hierarchy are used as constraints to reduce the combinatorial search space. These patterns may also be used to search for specified structure motifs by interactive retrieval.

Artificial Intelligence↗

PubMedDate not supplied

In two species, females exhibit superior working memory and inferior reference memory on the water radial-arm maze.

Male and female mice and rats were tested on a water escape version of the radial-arm maze designed to measure working and reference memory. In both species, females exhibited superior working memory during acquisition, and were better able to handle a higher memory load. However, male mice and rats exhibited better reference memory than females during the asymptotic portion of testing. Our data suggest that females may be better at working memory when both working and reference memory information must be learned simultaneously, and males better at reference memory when it has been differentiated from working memory.

Animals↗

PubMed2000

Learning and memory impairment in cocaine-dependent and comorbid schizophrenic patients.

Impairments in verbal learning and memory functioning have been found to be cardinal features among individuals with schizophrenia as well as among non-schizophrenic cocaine abusers. Cognitive deficits in these areas, moreover, have been associated with poor treatment response and short-term outcome. Little is known, however, about the acute effects of cocaine abuse on schizophrenic patients' learning and memory functioning. Consequently, a potentially reversible and treatable source of cognitive impairment has been virtually ignored. The present study examined the extent of verbal learning and memory impairment in a group of cocaine-dependent schizophrenic patients (n=42) and a group of non-schizophrenic cocaine-dependent patients (n=21) within 72 h of the last cocaine use using the California Verbal Learning Test (CVLT). Schizophrenic patients (n=34) without any substance-use disorders were also tested in an identical time frame and served as a comparison group. Results revealed that all groups demonstrated significant learning and memory impairment relative to CVLT published age and gender corrected norms. Both cocaine-dependent and non-substance abusing schizophrenic groups presented a very similar pattern of impaired learning and recall performance across all CVLT task domains. Comorbid patients, in contrast, presented with marked deficits in their ability to learn and recall verbal information relative to either schizophrenic or cocaine-only groups. Moreover, the cocaine-abusing schizophrenic patients showed significant forgetfulness of the information that they did acquire during delayed recall conditions. The performance deficits exhibited by cocaine-abusing schizophrenic patients differed not only in relative severity of impairment, but also qualitatively in their increased rates of forgetfulness of acquired information. These results are interpreted in terms of the neurobiological substrates of learning and memory and the neurobiological impact of cocaine on schizophrenic patients' cognition during the early phase of inpatient hospitalization. These results suggest that comorbid patients should be targeted for specialized remediation efforts at the beginning phases of inpatient treatment.

Acute Disease↗

PubMedDate not supplied

Does aspirin or other NSAIDs reduce the risk of cognitive decline in elderly persons? Results from a population-based study.

OBJECTIVE: To investigate the protective effect of NSAIDs and aspirin separately on cognitive decline in elderly subjects, controlling for consistent use of these agents over a prolonged period of time. METHODS: The study sample consisted of 1007 subjects, drawn from a population-based random sample of elderly individuals, 62-85 years old, who participated in a 3-year follow-up study. From this sample subjects were selected, who did use NSAIDs and completed all cognitive tests at both measurements (n=137), and subjects who did not use NSAIDs and completed all cognitive tests (n=475). Cognitive tests included the Mini-Mental State Examination (MMSE), tests for episodic memory (Auditory Verbal Learning Test) and information processing speed (coding task). Cognitive decline was computed using Edwards-Nunnally method. Multiple logistic regression analyses were performed to examine the association between NSAID (with and without aspirin) and decline in cognitive performance. Besides, the interaction of NSAIDs with age on cognitive decline was determined. RESULTS: The relative risk estimates of decline in episodic memory (immediate recall) adjusted for age, gender, education, baseline MMSE, vascular diseases, diabetes mellitus and (rheumatoid) arthritis for aspirin users only was more than three times reduced (OR: 0.30, 95% CI: 0.09-0.82). The odds ratio for decline in memory of NSAID use without aspirin, adjusted for age, gender, education, baseline MMSE, vascular diseases, diabetes mellitus and (rheumatoid) arthritis was not significant (OR: 1.00, 95% CI: 0.39-2.93). The effect of aspirin was significant only in persons of 75 years and over (OR: 0.10, 95% CI: 0.01-0.81), not in subjects younger than 75 years (OR: 0.52, 95% CI: 0.14-1.96). NSAIDs did not have benefit on information processing speed. In 92% of aspirin users a low dose of 100mg daily or less was used. CONCLUSION: Low-dose aspirin might be protective for decline in memory in individuals of 75 years and over. The benefit of a low-dose aspirin does not support an anti-inflammatory effect, but suggests an antiplatelet effect. Therefore, a possible protective effect of low-dose aspirin on cognitive decline is likely only in subjects with aspirin use over a prolonged period of time.

Aged↗

PubMed2001

Activation of the dopaminergic system of medial prefrontal cortex of gerbils during formation of relevant associations for the avoidance strategy in the shuttle-box.

1. A detailed analysis of behavior is a prerequisite for identification of components of information processing during learning. 2. Components of shuttle-box learning like the signal detection and signal evaluation can be differentiated using behavioral events such as the attention response and the orienting response. 3. Chiefly during evaluation of signal meaning in the acquisition phase of the avoidance strategy the extracellular DA is increased in mPFC. 4. The kinetics of prefrontal dopaminergic activation from trial to trial depends on the stage of avoidance learning. 5. The increase of DA in mPFC can be an indicator for the involvement of working memory principles in signal evaluation stages of conditioning.

Animals↗

PubMed1997

The daughters of diethylstilbestrol. Lessons from an error.

Diethylstilbestrol (DES) has been used extensively to prevent pregnancy disorders in Europe but at different levels depending upon the countries. Lessons from the DES story can be learned for research, information for physicians, communication, administration and industry. However, this paper will focus on the incidence of this story in our practice. We will propose guidelines for different conditions: clear cell adenocarcinoma, adenosis, cervical dysplasia, infertility and pregnancy.

Adenocarcinoma, Clear Cell↗

PubMedDate not supplied

The relationships between working memory and long-term memory.

Recent studies have led to the proposal that working memory operates not as a gateway between sensory input and long-term memory but as a workspace. The core of argument is that access to acquired knowledge and prior learning occurs before information becomes available to working memory. This proposition is a way to accommodate Baddeley's multiple component working memory model and the view that considers that working memory is nothing other than temporary activations of representations and procedures in long-term memory. However, this 'workspace' conception of working memory raises the question of the relationships between the central executive system and long-term memory.

Humans↗

PubMedDate not supplied

A behavioral teratogenic model of the impact of prenatal cocaine exposure on arousal regulatory systems.

Studies of both preclinical and human models of prenatal cocaine exposure suggest that one mechanism for the impact of cocaine on developing neural systems may be through functional alterations in monoaminergically regulated arousal systems. Conceptually, arousal regulation refers to a set of multimodal central nervous system mechanisms underlying cortical activation in response to internal and/or external stimulation. The emerging capacity for moment-to-moment regulation of states of arousal influences attentional states (e.g., posterior cortex) and executive functions (prefontal cortex) and thus information processing and learning as well as socialization. Furthermore, as a gating mechanism for response to novel and/or stressful conditions, arousal regulation is also a central construct for understanding stress reactivity and response to acute chronic trauma. In this paper, we review the findings of prenatal cocaine exposure in both preclinical and human studies with a particular focus on studies of neurobehavioral, neurocognitive functioning. A theoretical model of interactive arousal systems is presented as one possibility for integrating the profile of apparent cocaine-related neurobehavioral impairments in infants and young children prenatally exposed to cocaine.

Animals↗

PubMed2000

Blind signal processing by the adaptive activation function neurons.

The aim of this paper is to study an Information Theory based learning theory for neural units endowed with adaptive activation functions. The learning theory has the target to force the neuron to approximate the input-output transference that makes it flat (uniform) the probability density function of its output or, equivalently, that maximizes the entropy of the neuron response. Then, a network of adaptive activation function neurons is studied, and the effectiveness of the new structure is tested on Independent Component Analysis (ICA) problems. The new ICA neural algorithm is compared with the closely related 'Mixture of Densities' (MOD) technique by Xu et al.. Both simulation results and structural comparison show the new method is effective and more efficient in computational complexity.

Algorithms↗

PubMed2003

Hippocampal CA3 NMDA receptors are crucial for memory acquisition of one-time experience.

Lesion and pharmacological intervention studies have suggested that in both human patients and animals the hippocampus plays a crucial role in the rapid acquisition and storage of information from a novel one-time experience. However, how the hippocampus plays this role is poorly known. Here, we show that mice with NMDA receptor (NR) deletion restricted to CA3 pyramidal cells in adulthood are impaired in rapidly acquiring the memory of novel hidden platform locations in a delayed matching-to-place version of the Morris water maze task but are normal when tested with previously experienced platform locations. CA1 place cells in the mutant animals had place field sizes that were significantly larger in novel environments, but normal in familiar environments relative to those of control mice. These results suggest that CA3 NRs play a crucial role in rapid hippocampal encoding of novel information for fast learning of one-time experience.

Action Potentials↗

PubMed1991

Neural mechanisms of vocal production in songbirds.

Recent reports have described peripheral and central mechanisms of vocal production in songbirds. Respiratory patterning, individual syringeal muscles and the two syringeal halves have been shown to make specific contributions to learned vocalizations. New information on the function and organization of central pathways suggests how these production mechanisms may be controlled. The results are opening new avenues for further work on how acquired motor patterns are represented in this system.

Animals↗

PubMed2002

Providing the right infrastructure to lead the culture change for patient safety.

BACKGROUND: In early 2000 the hospital leadership of Good Samaritan Hospital (GSH), a community teaching hospital in Dayton, Ohio, made patient safety a strategic priority and devoted resources to incorporate safety as a part of the hospital's culture and care processes. The vice president of clinical effectiveness and performance improvement, as a champion for safety, led a consensus-building effort to enlist the support of key physician and hospital leaders to a safety program. GSH added a Safety Board to its administrative infrastructure, which was to serve as an oversight body to ensure the advance of the safety program and to produce policies and procedures that are associated with safety. ADDRESSING PATIENT SAFETY AIMS: To assess GSH's progress toward achieving three aims--demonstrate patient safety as a top leadership priority, promote a nonpunitive culture for sharing information and lessons learned, and implement an integrated patient safety program throughout the organization--the Safety Board evaluates GSH's performance bimonthly, using a 5-point-scaled self-assessment tool. For example, for the third aim, the Safety Board oversaw the formation of three subcommittees, which were to test ideas and achieve improvements in three areas--medication, clinical, and environmental. DISCUSSION: The administrative structure provides the leadership and momentum necessary to fuel a cultural change in the way that patient safety issues are perceived and acted on throughout the organization. "To err" may be human, but so is the ability to increase patient safety awareness, to promote cultural change within existing systems, and to improve the patient care processes and outcomes.

Consensus↗