[Neuro-and psychophysiologic aspects of memory: an oscillator-resonance model of extrasynaptic information storage].
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Humans↗
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Results for “Memory, Short-Term”
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[Assessment of vigilance].
Two aspects of vigilance are to be distinguished: the quantitative one refers to sleep-wakefulness dimension and the qualitative one refers to focusing of attention. Their combination leads to a curvilinear relationship between activation and performances. After describing the psychometric characteristics of vigilance tests, some examples are given of simple paper-pencil or more sophisticated methods. Physiological indices are also approached. The sources of variation influencing vigilance measurement are presented and also some useful experimental designs. At last some remarks are made on statistical exploitation and interpretation of results.
Attention↗
Effect of counterconditioning on test anxiety as indicated by digit span performance.
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Achievement↗
A psychometric evaluation of the acute tremulous state.
The acute alcohol withdrawal state (tremulous state), with mainly vegetative symptoms and without evident loss of conciousness or confusion, was evaluated as to functional psychopathological disturbances aiming to present a complete and objective record of the clinical findings and to establish a control of the course and drug treatment. We tried to meet the inherent inability to cooperate by using proven and also new test devices (flicker fusion, simple reaction time on light and tone, reaction on multiple serial stimuli, visual motor coordination, tachistoscopic perception and memory test, test of concentration and sustained performance with simple arithmetical calculation by analogy with the Pauli test) to circumvent the difficulties arising when patients have to answer long questionnaires. The tests enabled a measurement of the disturbances as objective as possible and proved to have a discriminating sensitivity for different functions. The correlations between the results were found to be similar for alcoholics and controls. tthe degree of the established functional cerebral and cerebellar defects which was revealed was more severe than expected in this mild stage of withdrawal.
Adult↗
[Effect of antiglial and antineuronal immunoglobulins on short-term and long-term memory in rats].
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Animals↗
Precocious aging and dementia in patients with Down's syndrome.
Fifty unselected institutionalized patients with Down's syndrome were studied to determine the clinical course of precocious aging and mental and neurological deterioration. In our studies we establish statistically significant differences in neurological and psychiatric abnormalities and mental deterioration in patients below and above age 35, indicating progressive changes in the central nervous system. We demonstrate higher incidence of recent memory loss, impairment of short-term visual retention, frontal release signs, hypertonia, hyperreflexia, long-tract signs, and psychiatric problems. We also note the presence of external features of precocious aging. Down's syndrome appears to be a human chromosomal abnormality in which genetically determined biochemical defects leading to precocious aging and dementia can be studied.
Adolescent↗
Delayed RNA changes in various neuron-neuroglia units of rat hypothalamus after short-term intermittent deep cooling with special reference to a concept of vegetative memory.
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Adaptation, Physiological↗
Use of concanavalin A to analyse the mechanism of memory cell differentiation into killer cells.
The renewing by ConA of the cytolytic activity evaluated in a short-term chromium release assay in a population of memory cells obtained in a long-term mixed lymphocyte culture is shown to be largely dependent upon the dose of ConA used; a three staged phenomenon in terms of dose response and kinetics is analysed and suggests that at least for low concentration of ConA (0.5 micrograms/ml) the lectin acts on the same subpopulation and through the same mechanism as the specific antigen, as shown by DNA-synthesis inhibition experiments. Preincubation with ConA at doses giving the best secondary-like response strongly inhibits further response to the primary alloantigen. Experiments using mixtures of ConA and alloantigens as stimulators show that both agents can compete in differentiating memory cells into killer cells. All these data suggest an important overlap of the structures on memory cells which are triggered by ConA or specific antigen.
Animals↗
Electromagnetic Radiation Stimulated Learning in Perovskite Nickelates.
Biological plasticity refers to the ability of synapses to strengthen or weaken over time. These adaptive properties play a fundamental role in learning and memory, spanning many orders of magnitude in timescales. Short-term plasticity (STP) arises from rapid correlative activity, while long-term plasticity (LTP) is governed by slower biochemical processes. Here, we investigate electromagnetically driven relaxation dynamics in perovskite nickelate thin films as an analogue of biological learning behaviors. By comparing radio frequency (RF), infrared (IR), visible, and ultraviolet (UV) radiation as stimuli, we find that RF excitation primarily induces STP, while visible and IR illumination lead to reversible relaxation on behavioral timescales. In contrast, UV illumination results in persistent, non-thermal changes in conductivity over extended timescales. Notably, UV-exposed nickelate films exhibit glass-like dynamics, characterized by stretched exponential relaxation and aging phenomena. The films display habituation to repeated stimuli, along with sensitization and spontaneous recovery under controlled environments. A minimal dynamical systems model captures key qualitative features of the UV-induced resistance changes. Our results demonstrate that electromagnetic frequency enables multi-timescale relaxation spanning nearly nine orders of magnitude, suggesting perovskite nickelates as promising platforms for adaptive optoelectronic hardware and for linking computational neuroscience with emerging quantum technologies.
electromagnetic radiation↗
Behavioral role of the mammillary efferent system.
The present study examined the effects of lesions of the mammillary system on spatial memory and arousal. Destruction of the medial mammillary nucleus or the mammillotegmental tract produces impairments on a delayed alternation task and greatly increases activity in the open-field. Lesions of the mammillothalamic tract produce a differential effect in that the spatial alternation deficit is accompanied by a general lethargy and unresponsiveness. It is suggested that the mammillary system plays a crucial role in the short-term storage of proprioceptive information necessary for the successive execution of maze choices. It also appears to play a role in the arousal state of the animal.
Animals↗
Secondary cytotoxic response in vitro against Moloney lymphoma cells antigenically altered by drug treatment in vivo.
Cell-mediated cytotoxic response in vitro to a Moloney strain of murine leukemia virus-induced tumor (LSTRA) altered by 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC) was investigated with the use of mixed-leukocyte tumor cell cultures (MLTC). As assessed by means of a short-term 51Cr-release assay, minimal or no cytolytic activity was generated in primary MLTC. In contrast, high specific cytotoxic response against the altered tumor was obtained in secondary MLTC. Partial cross reactivity was found between the LSTRA and LSTRA/DTIC tumor lines.
Animals↗
Impact of Chewing Behavior Change on Cognition and Cerebral Hemodynamics.
BACKGROUND: Impaired chewing ability is a recognized risk factor for cognitive decline in older adults, potentially due to reduced neural stimulation in cognition-related brain regions. While short-term studies have demonstrated transient increases in neural activity from chewing, the sustained cognitive and neurophysiological effects of encouraging thorough chewing habits in daily life remain unclear. OBJECTIVE: This randomized controlled trial investigated whether promoting thorough chewing during meals could improve cognitive function and cerebral hemodynamics in older adults. METHODS: Fifty participants aged 65 y or older were randomly assigned to either a 1-mo intervention group, which used a wearable device to monitor and increase chewing strokes during meals, or a control group that maintained usual chewing habits. Chewing behavior, cognitive performance (including memory and executive function via the color Stroop test), and cerebral hemodynamics in the dorsolateral prefrontal cortex (DLPFC) were measured at baseline and after 1 mo. Statistical analyses included t tests, chi-square tests, 2-way analysis of variance with post hoc tests, Pearson correlations, and generalized linear models to evaluate group differences and associations between chewing and cognitive outcomes. RESULTS: Significant time-by-group interactions were observed for memory, F(1, 48) = 6.24, P = 0.043, and hemodynamic responses in the left DLPFC, F(1, 48) = 6.19, P = 0.013. The intervention group showed increased chewing frequency (P = 0.017), improved memory performance, and reduced left DLPFC responses compared with controls. Chewing frequency was positively correlated with Stroop test scores (r = 0.53, P = 0.010) and negatively with hemodynamic changes in the left DLPFC (r = -0.30, P = 0.040). Although improvements in other cognitive outcomes and hemodynamic measures favored the intervention group, these differences did not reach statistical significance. CONCLUSIONS: Promoting intentional chewing habits for 1 mo may enhance memory-related cognitive performance and neural efficiency in the DLPFC during working memory tasks in older adults. This nonpharmacologic, low-burden strategy warrants further research with longer interventions to support cognitive health and dementia prevention. TRIAL REGISTRATION ID: UMIN000044280Knowledge Transfer Statement:This study demonstrates that promoting thorough chewing habits in older adults can improve memory and enhance neural efficiency in the brain. Encouraging intentional mastication is a simple, nonpharmacologic approach that may help maintain cognitive health and prevent dementia, providing a practical strategy for clinicians and policymakers to support healthy aging.
Humans↗
Primary and secondary in vitro generation of cytolytic T lymphocytes in the murine sarcoma virus system.
Cell-mediated cytotoxic responses in vitro to surface antigens associated with murine sarcoma virus (MSV)-induced tumors were investigated using mixed leukocyte-tumor cell cultures (MLTC). The source of responding cells was either spleens from normal C57BL/6 mice (primary MLTC) or spleens of C57BL/6 mice carrying or having rejected a MSV-induced tumor (secondary MLTC). Graffi virus-induced GiL-4 leukemia cells, Rauscher virus-induced RB1-5 leukemia cells, and MSV-induced MSV-B16 sarcoma cells were used as stimulating syngeneic tumor cells and/or target cells. Under appropriate culture conditions, cytolytic T lymphocytes (CTL) were generated in both primary and secondary MLTC. As assessed by a quantitative short-term 51Cr release assay system, CTL activity in secondary MLTC populations was at least 10-fold higher than that in primary MLTC populations, and 100-fold higher than that in spleen cells taken at the peak of the in vivo response of MSV-infected mice. The ability of spleen cells to mount a secondary CTL response in vitro could be observed as early as 5 days after virus injection, increased up to the time of maximum tumor size and persisted long after tumor regression. This suggests the development of increased numbers of CTL progenitors and/or the formation of "memory" CTL in spleens of MSV-injected mice.
Animals↗
Comparing trajectories of cognitive functioning in treatment-resistant and non-resistant depression: a multicentre linear mixed-effects analysis.
BACKGROUND: Impaired cognitive functioning is a severe symptom in major depressive disorder (MDD). Recent evidence suggests it may be a central characteristic in its treatment resistant form (TRD), potentially constituting a clinical marker for treatment resistance and a target amenable to intervention. To date, cognitive functioning in TRD remains poorly understood and longitudinal investigations are scarce. METHODS: This observational prospective cohort study, including 320 patients diagnosed with MDD from the multicentre PROMPT study, examined differences in cognitive functioning between 118 TRD and 202 non-TRD patients over a period of twelve weeks in a real-world setting, using linear mixed modelling. Patients that failed to respond to at least two prior antidepressants trials at baseline were classified as TRD. RESULTS: TRD patients showed significantly poorer baseline performances than non-TRD patients in attention/processing speed (β = -0.45; 95%CI[-0.70, -0.19]; FDR-p = 0.003) and verbal memory (β = -0.45; 95%CI[-0.72, -0.18]; FDR-p = 0.003). Significant time × group interactions were observed in motor speed and verbal fluency tasks. Post-hoc-analyses revealed stagnation in TRD patients and significant improvement in non-TRD patients. Across all other tasks improvement was observed in both groups, and random effects showed large heterogeneity between patients, indicating notable individual differences in cognitive performances. CONCLUSIONS: The results suggest distinct recovery patters between non-TRD and TRD patients, and diminished functioning in TRD patients at the domain level. However, intact and diminished performances likely occur in both groups, warranting further investigation of cognitive heterogeneity. These short-term findings highlight the need for more comprehensive longitudinal research on cognition in TRD.
Humans↗
Generation of cytolytic T lymphocytes in vitro. X. Induction of primary and secondary CTL responses by the mitogen sodium periodate.
Short-term (15 min) sodium periodate (NaIO4) treatment of mouse spleen cells previously primed in vivo or in vitro against alloantigens induced the formation of secondary (2 degree) cytolytic T lymphocytes (CTL) specific for the priming antigens. CTL formation was readily demonstrable within 24 hr after treatment. This early CTL response occurred equally well in the presence or absence of cytosine arabinoside (Ara C), indicating that NaIO4 could induce CTL independently of DNA synthesis. Forty-eight hours after periodate treatment, the lytic activity was similar to that observed in parallel cultures stimulated with irradiated allogeneic spleen cells, although the peak activity was reached earlier (day 4) and was somewhat lower than that induced by alloantigen. The addition of irradiated NaIO4-treated unprimed syngeneic spleen cells to cultures of untreated alloimmune spleen cells also led to CTL formation, which suggests an indirect mechanism of activation. In contrast to alloimmune spleen cells, normal spleen cells treated with NaIO4 developed only very low levels of cytotoxicity after 4 days of incubation. However, in the presence of PHA, such cells were capable of lysing syngeneic and allogeneic target cells.
Animals↗
Antigenic specificity of the cytolytic T lymphocyte (CTL) response to murine sarcoma virus-induced tumors. I. Preferential reactivity of in vitro generated secondary CTL with syngeneic tumor cells.
Incubation of spleen cells from mice having rejected a Moloney sarcoma virus (MSV)-induced tumor with syngeneic irradiated lymphoma or sarcoma cells bearing MSV-associated antigens in secondary mixed leukocyte-tumor cell cultures (MLTC) resulted in the generation of highly active cytolytic T lymphocytes (CTL) specifically directed against syngeneic target cells bearing MSV-associated antigens. When MSV-immune spleen cells from C57BL/6 (H-2b) and BALB/c(H-2d) mice were compared with respect to their ability to generate CTL in syngeneic secondary MLTC, it was found that both lymphoid cell populations were equally able to mount an anamnestic CTL response to MSV-associated antigens as assessed by a short-term 21Cr release assay. However, quantitative analysis of the activity of both CTL populations on either H-2b or H-2d tumor cells indicated that target cells sharing the same major histocompatibility complex (MHC) as the effector cells were lysed 10- to 100-fold more efficiently than allogeneic target cells. As suggested by the results of inhibition experiments using mixtures of 51Cr-labeled and unlabeled target cells, preferential lysis of syngeneic versus allogeneic tumor cells might be related to the establishment of effective adhesions between the former and CTL. Direct evidence for the role of MHC in determining the antigenic specificity of CTL directed against MSV-associated antigens was provided by results obtained using MSV-immune spleen cells from congenic resistant mice. Furthermore, studies of the response of F1 (H-2b/d) hybrid mice showed that stimulation of immune spleen cells with tumor cells from one parental strain or the other in secondary MLTC resulted in the generation of CTL capable of lysing tumor target cells of the same perental strain as the stimulating cells, but not of the other. The results thus suggested the presence of two sets of CTL precursor cells in F1 MSV-immune spleens, each set responding exclusively to tumor antigens associated with only one of the two parental phenotypes.
Animals↗
Intratumoral B cell and interferon signatures in newly diagnosed glioblastoma are associated with longer survival in patients treated with SurVaxM.
Glioblastoma (GBM) has proved difficult to treat, and there is dire need for more effective therapies. In a single arm phase IIa trial (NCT02455557), treatment of newly diagnosed GBM patients with the peptide vaccine SurVaxM resulted in promising median progression-free and overall survival. To investigate molecular features that associate with GBM responsiveness to SurVaxM, retrospective whole exome and RNA sequencing was performed on patient tumors (n = 34) collected prior to standard of care treatment plus SurVaxM. Differential gene expression and mutational profiles were characterized between patients with short-term (OS < 18 months) or long-term (OS ≥ 18 months) overall survival. Greater expression of interferon, complement, and humoral immunity signatures were associated with long-term survival. Deconvolution of transcriptomes identified enrichment of intratumoral memory B cell populations in long-term survivors that were validated by CD20 staining in matched samples. A five-gene expression signature and a B cell specific signature predicted survival within the SurVaxM-treated cohort, however, these signatures were not associated with improved outcomes in a similarly treated population obtained from The Cancer Genome Atlas (TCGA) that did not receive immunotherapeutic intervention. Although prospective validation is ongoing, the findings in this discovery cohort specify molecular features of GBM associated with better overall survival and potential responsiveness to immunotherapy with SurVaxM.
Humans↗