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remote memory [keywords]
- Physical Exercise during Encoding Improves Vocabulary Learning in Young Female Adults: A Neuroendocrinological Study. [JOURNAL ARTICLE]
- PLoS One 2013; 8(5):e64172.
Acute physical activity has been repeatedly shown to improve various cognitive functions. However, there have been no investigations comparing the effects of exercise during verbal encoding versus exercise prior to encoding on long-term memory performance. In this current psychoneuroendocrinological study we aim to test whether light to moderate ergometric bicycling during vocabulary encoding enhances subsequent recall compared to encoding during physical rest and encoding after being physically active. Furthermore, we examined the kinetics of brain-derived neurotrophic factor (BDNF) in serum which has been previously shown to correlate with learning performance. We also controlled for the BDNF val66met polymorphism. We found better vocabulary test performance for subjects that were physically active during the encoding phase compared to sedentary subjects. Post-hoc tests revealed that this effect was particularly present in initially low performers. BDNF in serum and BDNF genotype failed to account for the current result. Our data indicates that light to moderate simultaneous physical activity during encoding, but not prior to encoding, is beneficial for subsequent recall of new items.
- Endoscopic Management of Colloid Cysts. [JOURNAL ARTICLE]
- J Neurol Surg A Cent Eur Neurosurg 2013 May 22.
Background Microsurgical resection, stereotactic aspiration, endoscopically assisted microsurgical resection, and ventriculoperitoneal shunt have been the treatment options for colloid cysts of the third ventricle. Recently, an endoscopic approach has been recognized as an effective alternative to open surgery. There is suspicion about the long-term recurrence rate and about obtaining complete removal of cyst.Patients and Methods This is a prospective study of 24 patients with colloid cyst who underwent endoscopic resection. Preoperative computed tomography (CT) scans revealed hydrocephalus in all the patients. Postoperative magnetic resonance imaging (MRI) was done in all cases.Results Age ranged from 16 to 57 years. There were 16 male and 8 female patients. The diameter of the cyst varied from 14 to 24 mm. Operating time ranged from 90 to 156 minutes. Total resection was achieved in 21 patients. All patients with subtotal excision underwent coagulation of residual cyst wall. The follow-up period ranged from 6 to 78 months (mean, 37 months). None of the patients developed any symptoms at 26, 31, and 39 months of follow-up. Preoperative symptoms disappeared in all the patients except for memory disorders and seizures in one patient each. No residual cyst was observed on the postoperative MRIs in 21 patients. Hospital stay was 4 to 10 days (median, 6 days). No endoscopic operation was converted into an open resection.Conclusion Endoscopic excision of a colloid cyst is an effective and safe alternate method. Although the follow-up time was short, residual cyst wall remained asymptomatic without any evidence of growth after subtotal excision and coagulation of wall.
- Executive Functioning Skills in Long-Term Users of Cochlear Implants: A Case Control Study. [JOURNAL ARTICLE]
- J Pediatr Psychol 2013 May 22.
OBJECTIVE:To investigate differences in executive functioning between deaf children with cochlear implants (CIs) and normal-hearing (NH) peers. The cognitive effects of auditory deprivation in childhood may extend beyond speech-language skills to more domain-general areas including executive functioning.
METHODS:Executive functioning skills in a sample of 53 prelingually deaf children, adolescents, and young adults who received CIs prior to age 7 years and who had used their CIs for ≥7 years were compared with age- and nonverbal IQ-matched NH peers and with scale norms.
RESULTS:Despite having above average nonverbal IQ, the CI sample scored lower than the NH sample and test norms on several measures of short-term/working memory, fluency-speed, and inhibition-concentration. Executive functioning was unrelated to most demographic and hearing history characteristics.
CONCLUSIONS:Prelingual deafness and long-term use of CIs was associated with increased risk of weaknesses in executive functioning.
- Preconditioning and post-treatment with cobalt chloride in rat model of perinatal hypoxic-ischemic encephalopathy. [JOURNAL ARTICLE]
- Brain Dev 2013 May 18.
Background:Hypoxia-ischemia (HI)-induced perinatal encephalopathy is a major cause of acute mortality and chronic neurologic morbidities such as cerebral palsy, mental retardation, and epilepsy. As the essential transcription factor for the activation of hypoxia-inducible genes, hypoxia-inducible factor 1 alpha (HIF-1α) plays an important role in the pathophysiological response to the stress of HI brain damage. Whether HIF-1α activation promotes neuroprotection in HI tissues is controversial.
Methods:The left common carotid artery of rats aged 7days was ligated under anesthesia. The pups were then exposed to hypoxia in a normobaric chamber filled with 8% oxygen and 92% nitrogen for 2.5h. In the sham control group, the left common carotid artery was exposed but was not ligated or exposed to hypoxia. To assess the time window for effective treatment, the HIF-1α inducer cobalt chloride (CoCl2) was injected subcutaneously 1day before surgery, immediately or 1day after surgery. The brain tissues were harvested from the pups of each groups at 1, 2 and 7days after insult for HIF-1α protein ant its target genes expression and for investigating the injury. Morris water maze tests were performed at postnatal 7weeks.
Results:HIF-1α protein levels and its target genes vascular endothelial growth factor, heme oxygenase-1, and insulin-like growth factor 1 were markedly increased after intraperitoneal injection of CoCl2 (60mg/kg). The target gene inducible nitric oxide synthase exhibited a biphasic time course. HI caused apoptosis and reduced capillary density, which were ameliorated by CoCl2. Both preconditioning with CoCl2 24h before HI and administration of CoCl2 24h after HI improved long-term reference memory compared with that in vehicle-injected littermate controls. Administration of CoCl2 immediately after HI did not improve spatial working memory.
Conclusions:CoCl2 activates HIF-1α and protects against brain damage in vivo. The time of administration could be used to manipulate the activity of HIF-1α pathways and promote recovery.
- [Epigenetic regulation in neuronal differentiation and brain function]. [English Abstract, Journal Article]
- Biol Aujourdhui 2013; 207(1):1-17.
DNA methylation compacts chromatin structure and represses gene transcription. It is important for numerous cellular processes, including embryonic development, X-chromosome inactivation, suppression of transposable elements, and cellular differentiation. In addition, environmental cues, including drugs, pollutants, trauma or early-life social environment, alter DNA methylation patterns in different organs. For instance, studies have unravelled a complex and dynamic interplay between environment, DNA methylation and neuron function during development and in the adult. This crosstalk is hypothesized as an essential molecular event underlying the effects of long-term memory, drug addiction, and several psychotic and behavioural disorders. In this review, we give a summary of this exciting field of research and highlight the molecular functions of DNA methylation and of proteins interacting with methylated DNA.
- The preview benefit for familiar and unfamiliar faces. [JOURNAL ARTICLE]
- Vision Res 2013 May 18.
Previewing distracters improves visual search - the preview benefit (Watson & Humphreys, 1997). Recent fMRI evidence suggests that the preview benefit rests on active inhibition in brain regions concerned with spatial memory, as well as in content selective areas (Allen, Humphreys, & Matthews, 2008). Using familiar and unfamiliar faces in a preview search task we show that search performance is much better with familiar than with unfamiliar faces. With both types of stimuli we obtained preview benefits of at least 10%, measured in terms of the advantage in reaction time relative to the no preview condition. The preview benefit increased up to 30% when distracter faces and their locations were previewed, compared to a benefit in the range of 10% to 25% for previewing just distracter locations. Analysis in terms of search time per item showed that familiar faces were processed with more than double the efficiency of the unfamiliar faces. Further, efficiency was enhanced relative to the no preview condition only when distracter locations and content were previewed, but not when participants previewed just distracter locations. These findings corroborate that the preview benefit involves both spatial and content-specific mechanisms, and indicate contribution of existing long-term memory representations independent of spatial memory.
- Vascular dementia with left thalamic infarction: Neuropsychological and behavioral implications suggested by involvement of the thalamic nucleus and the remote effect on cerebral cortex. The Osaki-Tajiri project. [JOURNAL ARTICLE]
- Psychiatry Res 2013 May 18.
Vascular dementia (VaD) is a condition whereby decreased cerebral perfusion causes cognitive deterioration. We hypothesized that lesions of the anterior nucleus (AN) including the mammillo-thalamic tract cause a decline in the recollection of past episodes/events, and that the left thalamic infarction can cause frontal dysfunction through the "diaschisis." We investigated 18 VaD cases with only left thalamic infarction. (99m)Tc-ECD single photon emission computed tomography (SPECT) was used to assess regional cerebral blood flow (CBF). To test the first hypothesis, the scores on the Cognitive Abilities Screening Instrument (CASI) domain Recent memory or the rating on the Clinical Dementia Rating (CDR) domain Memory were analyzed. To test the second hypothesis, we selected the six regions of interest that correlated with the two measures, i.e., word fluency and/or depressive state, as assessed with the Geriatric Depression Scale (GDS). We found that all patients had amnesia, especially in the AN group, six of the eight patients had scores of 1+ on the CDR Memory scale, and all but one disclosed the CASI domain Recent memory impairment. There were significant correlations between the left anterior cingulate CBF and word fluency scores, and between the right rectal gyrus CBF and GDS scores. We suggest that these observations are due to a remote effect of the thalamic lesion.
- The short and long term effects of docetaxel chemotherapy on rodent object recognition and spatial reference memory. [JOURNAL ARTICLE]
- Life Sci 2013 May 18.
AIMS:Previous animal studies have examined the potential for cytostatic drugs to induce learning and memory deficits in laboratory animals but, to date, there is no pre-clinical evidence that taxanes have the potential to cause cognitive impairment. Therefore our aim was to explore the short- and long-term cognitive effects of different dosing schedules of the taxane docetaxel (DTX) on laboratory rodents. MAIN
METHODS:Healthy male hooded Wistar rats were treated with DTX (6mg/kg, 10mg/kg) or physiological saline (control), once a week for 3-weeks (Experiment 1) or once only (10mg/kg; Experiment 2). Cognitive function was assessed using the novel object recognition (NOR) task and spatial water maze (WM) task 1 to 3 weeks after treatment and again 4 months after treatment. KEY
FINDINGS:Shortly after DTX treatment, rats perform poorly on NOR regardless of treatment regimen. Treatment with a single injection of 10mg/kg DTX does not appear to induce sustained deficits in object recognition or peripheral neuropathy.
SIGNIFICANCE:Overall these findings show treatment with the taxane DTX in the absence of cancer and other anti-cancer treatments causes cognitive impairment in healthy rodents.
- Administration of glucosylceramide ameliorated the memory impairment in aged mice. [Journal Article]
- Evid Based Complement Alternat Med 2013.:824120.
The function and the role of glucosylceramide have not been well studied in the central nervous system. This study was aimed to investigate the possible roles of glucosylceramide in memory function in aged mice. Glucosylceramide (50 mg/kg, p.o.) showed memory enhancing activity after 3-month treatment in the aged mice (C56BL/6, 18-20 months old) through Y-maze, novel objective test, and Morris water maze test. Long-term treatment of glucosylceramide decreased the expression of iNOS and COX-2 in the brain of aged mice. The LPS-induced mRNA level of iNOS, COX-2, IL-1 β , and TNF- α was reduced by the acute treatment with glucosylceramide in adult mice. These results suggest that glucosylceramide plays an important role in anti-inflammatory and memory enhancement, and it could be a potential new therapeutic agent for the treatment of neurodegenerative diseases such as Alzheimer's disease.
- Enhanced immune response against HIV-1 induced by a heterologous DNA prime-adenovirus boost vaccination using mannosylated polyethyleneimine as DNA vaccine adjuvant. [Journal Article]
- Int J Nanomedicine 2013.:1843-54.
The heterologous deoxyribonucleic acid (DNA) prime-adenovirus (AdV) boost vaccination approach has been widely applied as a promising strategy against human immunodeficiency virus (HIV)-1. However, the problem of inefficient delivery and lack of specificity of DNA vaccine remains a major issue. In this paper, to improve the transfection of DNA vaccine and realize dendritic cell targeting, we used mannosylated polyethyleneimine (man-PEI) as a DNA vector carrier.The DNA plasmid encoding antigen HIV gag fragment was constructed by polymerase chain reaction. Then the DNA plasmid was complexed with man-PEI. The in vitro transfection efficiency of man-PEI/DNA was analyzed on DC 2.4 cells. Mice were primed with 25 μg pVAX1-HIV gag plasmid complexed with man-PEI, 100 μg naked pVAX1-HIV gag plasmid, or empty pVAX1 vector and boosted by AdV encoding the same antigen. The antibody titer, CD4(+) and CD8(+) T-cell response, as well as interferon-γ and interleukin-4 levels in serum and in splenocytes culture were analyzed using flow cytometry or enzyme-linked immunosorbent assay to evaluate the immune response. To test a long-term effect of the vaccination regimen, CD8(+) memory T-cell was also detected by flow cytometry.The pVAX1-HIV gag was constructed successfully. The in vitro transfection efficiency in dendritic cells was significantly higher than naked DNA plasmid. Compared with 100 μg naked DNA/AdV group, the immunoglobulin G2a antibody titer, T-cell response percentage, and cytokine production level induced by man-PEI/DNA/AdV group were significantly higher at a lower DNA dose. Also, the man-PEI/DNA could stimulate a memory CD8(+) T-cell response.Owing to the adjuvant effect of man-PEI, the man-PEI/pVAX1-HIV gag priming plus AdV boosting strategy proved to be a potent vaccine candidate against HIV, which could induce a stronger immune response with a lower DNA dose.