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PubMed2004

Factor structure of the Wide Range Assessment of Memory and Learning (WRAML) in children with insulin dependent diabetes mellitus (IDDM).

Maximum likelihood confirmatory factor analysis was performed with the Wide Range Assessment of Memory and Learning (WRAML) for a clinical sample of 246 children with insulin-dependent diabetes mellitus (IDDM). Consistent with previous literature examining the factor structure of the WRAML, findings supported the validity of a three-factor model including Verbal Memory, Visual Memory, and Attention/Concentration (AC) factors for this clinical sample. However, in contrast to previous factor analytic research, results also supported the validity of an alternative two-factor model consisting of a combined modality Memory/Learning (ML) factor and an AC factor. While the results suggest that the three-factor solution may provide an adequate characterization of memory and learning in the majority of this sample of children with IDDM, it appears that certain groups of children with IDDM, particularly those children with early disease onset and those who experience hypoglycemic seizures, may exhibit a specific profile of differences that may result in a lack of differentiation between the verbal and visual modalities.

Adolescent↗
PubMed1982

Effects of the novel compound aniracetam (Ro 13-5057) upon impaired learning and memory in rodents.

The effect of aniracetam (Ro 13-5057, 1-anisoyl-2-pyrrolidinone) was studied on various forms of experimentally impaired cognitive functions (learning and memory) in rodents and produced the following effects: (1) almost complete prevention of the incapacity to learn a discrete escape response in rats exposed to sublethal hypercapnia immediately before the acquisition session; (2) partial (rats) or complete (mice) prevention of the scopolamine-induced short-term amnesia for a passive avoidance task; (3) complete protection against amnesia for a passive avoidance task in rats submitted to electroconvulsive shock immediately after avoidance acquisition; (4) prevention of the long-term retention- or retrieval-deficit for a passive avoidance task induced in rats and mice by chloramphenicol or cycloheximide administered immediately after acquisition; (5) reversal, when administered as late as 1 h before the retention test, of the deficit in retention or retrieval of a passive avoidance task induced by cycloheximide injected 2 days previously; (6) prevention of the deficit in the retrieval of an active avoidance task induced in mice by subconvulsant electroshock or hypercapnia applied immediately before retrieval testing (24 h after acquisition). These improvements or normalizations of impaired cognitive functions were seen at oral aniracetam doses of 10-100 mg/kg. Generally, the dose-response curves were bell-shaped. The mechanisms underlying the activity of aniracetam and its 'therapeutic window' are unknown. Piracetam, another pyrrolidinone derivative was used for comparison. It was active only in six of nine tests and had about one-tenth the potency of aniracetam. The results indicate that aniracetam improves cognitive functions which are impaired by different procedure and in different phases of the learning and memory process.

Animals↗
PubMed2000

[The role of theophylline in the improvement of scop-induced learning and memory impairment].

Adenosine and ACh contents in hippocampus, striatum region around the nucleus of basal meynert (NBM) and the frontal and temporal parts of rat cortex were measured by a high performance liquid chromotography-electronic detector (HPLC-ECD). Adenosine content in 18~20 month-old rats was significantly higher than that of 3~6 month-old rats, while ACh content in 18~20 month-old rats was lower than that of 3~6 month-old ones. Learning and memory impairment models were established by induction of SD rats with scopolamine (0.5 mg/kg, ip), which were injected with an adenosine receptor antagonist theophylline (1.0 mg/5 microliter, icv), and the step-down test was performed. The error frequency in the step-down test decreased significantly (P<<0.05), and the retention time was longer than that of control. Furthermore, ACh content increased in all the three different brain regions. The above results suggest that adenosine may play an important role in senile learning and memory impairment, and theophylline may improve scopolamine-induced learning and memory impairment by increasing ACh content. In consequence, theophylline could be a promising drug for ameliorating senile learning and memory impairment.

Acetylcholine↗
PubMed2005

Learning and memory in aging combat veterans with PTSD.

The California Verbal Learning Test (CVLT) was administered to examine learning and memory performance in aging combat veterans with (n = 30) and without PTSD (n = 20), and veterans unexposed to combat (n = 15). Combat veterans with PTSD (PTSD+) showed many impairments compared to non-exposed veterans, but only long-delay free recall consistently discriminated the PTSD+ group from combat-exposed subjects without PTSD (PTSD-), when data were corrected for subscale scores on the WAIS (Vocabulary, Block Design). Alterations in total learning were associated with PTSD when controlling for substance abuse and depression. Two contrast measures, proactive interference and recognition hits, distinguished combat from noncombat veterans, and may be related to trauma exposure. Impairments in total learning are similar to what has been observed in Holocaust survivors. However, increased severity of rapid forgetting may be a specific alteration in older combat veterans, likely reflecting aspects of both combat exposure and aging.

Aged↗
PubMed2004

Contribution of organizational strategy to verbal learning and memory in adults with attention-deficit/hyperactivity disorder.

Statistical mediation modeling was used to test the hypothesis that poor use of a semantic organizational strategy contributes to verbal learning and memory deficits in adults with attention-deficit/hyperactivity disorder (ADHD). Comparison of 28 adults with ADHD and 34 healthy controls revealed lower performance by the ADHD group on tests of verbal learning and memory, sustained attention, and use of semantic organization during encoding. Mediation modeling indicated that state anxiety, but not semantic organization, significantly contributed to the prediction of both learning and delayed recall in the ADHD group. The pattern of findings suggests that decreased verbal learning and memory in adult ADHD is due in part to situational anxiety and not to poor use of organizational strategies during encoding.

Adult↗
PubMed2000

[Effects of chronic stress on the learning and memory ability and hippocampal LTP in rats].

AIM AND METHODS: A chronic stress model in 21 days with multi-stressors was applied to question the effects of stress on the learning and memory ability and the hippocampal neuronal synaptic plasticity in rats, using the Y maze test and LTP electrophysiological recording in vivo. RESULTS: The impairment of spatial learning and memory ability and an obvious suppression in LTP in hippocampal dentate gyrus was observed in stress group after chronic stress. CONCLUSION: The hippocampal synaptic plasticity may be decreased by the chronic stress. And then, the learning and memory ability may also be impaired consequently.

Animals↗
PubMedDate not supplied

The effects of peripheral endocrine hormone deficiencies on the processes of behavior, learning, and memory.

The effects of thyroid and adrenal cortex hormone and sex hormone deficiencies on the ability to learn, store memory traces, and behave were compared in male rats. These studies showed that removal of peripheral endocrine glands led to disruption of the learning process and the ability to reproduce learned information and also produced alterations in behavior. Analysis of the results showed that corticosteroid hormones are directly involved in the processes of learning and behavior. Sex and thyroid hormones appear to have modulatory effects on higher nervous activity.

Adrenal Cortex Hormones↗
PubMed1998

Can Cerebrolysin influence chronic deterioration of spatial learning and memory?

Our previous studies showed that the nootropic drug Cerebrolysin, applied immediately after the traumatic or excitotoxic brain lesion influenced spatial learning and memory. Long-lasting ameliorative effect of Cerebrolysin was found after its 4-week-administration, while two-week-treatment had only temporal effect. With the aim to verify the capability of Cerebrolysin to restore chronically deteriorated learning and memory. The drug was applied 4 months after lesioning the rat's CNS. The present study shows that Cerebrolysin restored learning capability of the lesioned rats. Although their spatial memory was improved in comparison to lesion untreated controls, it did not reach the level of intact controls. The effect was more pronounced after the application of 1.25 ml/kg b. w. of Cerebrolysin than after the application of 2.5 ml/kg b. w.

Amino Acids↗
PubMed2005

Motherhood mitigates aging-related decrements in learning and memory and positively affects brain aging in the rat.

The current work examined spatial learning and memory (i.e., latencies to find a baited food well) in age-matched nulliparous, primiparous and multiparous (NULL, PRIM and MULT, zero, one or two pregnancies and lactations, respectively). We tested at 6, 12, 18 and 24 months of age in a dry land version of the Morris water maze (Main task), and at 12, 18 and 24 months in the same task in which the original location of the baited well was changed (Reversal task). We show that PRIM/MULT rats, compared to the age-matched NULL females, learned the spatial tasks significantly better and exhibited attenuated memory decline, up to 24 months of age. Furthermore, at the conclusion of behavioral testing, we investigated levels of these animals' hippocampal (CA1 and dentate gyrus) immunoreactive amyloid precursor protein (APP), a marker of neurodegeneration and age-related cognitive loss. MULTs had significantly reduced APP in both CA1 and DG, relative to PRIMs and NULLs, and PRIMs had a trend (p<0.06) toward a reduction in APP compared to NULLs in DG. Further, level of APP was negatively correlated with performance in the two tasks (viz., more APP, worse maze performance). Reproduction, therefore, with its attendant natural endocrine and postpartum sensory experiences, may facilitate lifelong learning and memory, and may mitigate markers of neural aging, in the rat. Combining natural hormonal exposure with subsequent substantial experience with stimuli from the offspring may preserve the aged parous female brain relative to that of NULL females.

Age Factors↗
PubMed1999

Comparative effects of prenatal and postnatal undernutrition on learning and memory in rats.

Effects of pre- and post-natal undernutrition on learning and memory parameters were studied in albino rats. Prenatal undernutrition was induced in rat pups by restricting the mother's diet by 50% during the entire gestation period, whereas postnatal undernutrition was induced in rat pups by restriction of their diet by rotating them between lactating and non-lactating maternalised females for 12 hr each day during suckling period from 2nd day to 18th day after birth. At 2.5 to 3 months of age all the rat offsprings were subjected to (i) original and reversal discrimination learning, (ii) passive avoidance, and (iii) active avoidance and its retention tests. The results indicate that both pre- and post-natal undernutrition in rat pups caused significant deficits in original and reversal discrimination learning, retention of passive avoidance after one week retention interval, and retention of active of avoidance learning. However, both pre- and post-natal undernutrition did not show significant effect on acquisition of active avoidance and retention of passive avoidance after 24 hr retention interval.

Animals↗
PubMed1996

Spatial learning and memory in calpastatin-deficient rats.

The present experiments were concerned with the examination of the hypothesis that a deficiency in calpastatin, the endogenous inhibitor of calpain, enhances learning and memory performance. In the first experiment we used rats with an altered calpain/calpastatin balance (Milan hypertensive strain, MHS, low calpastatin) to investigate the learning and memory of a spatial task in the Morris water maze in comparison with control rats with a normal calpain/calpastatin balance (Milan normotensive strain, MNS). Since the two strains also differ in blood pressure, a third strain of rats was included to assess the role of hypertension (spontaneously hypertensive rats, SHR). Although the acquisition rate of the spatial task was better in the low-calpastatin MHS rats than in their normal-calpastatin MNS controls, their performance was similar to that of the SHR rats, thus thwarting the conclusion that differences were due to the low level of calpastatin. The availability of another mutant strain, low-calpastatin level and normotensive (MH.NE), allowed a further examination of the hypothesis. In the second experiment rats of the MH.NE strain acquired the spatial task as well as their normotensive controls, but their memory retrieval was clearly less than that of their normal-calpastatin controls. This deficiency was not due to impaired visual function or a slower swimming speed. The conclusion is that an inbalanced calpain/calpastatin ratio, although favoring calpain activity, is disadvantageous for remembering a spatial task. This disadvantage is clearly overruled when this inbalance is accompanied by hypertension.

Animals↗
PubMed2003

Comparison of the effects of early handling and early deprivation on conditioned stimulus, context, and spatial learning and memory in adult rats.

Effects of manipulations of the rat pup-dam relationship on affective learning and memory in adulthood have received scant systematic investigation. The authors previously described how early handling (EH; 15 min isolation/day) and early deprivation (ED; 4 hr isolation/day) exert similar effects on spontaneous adult affect (open-field behavior, acoustic startle, endocrine stress response) relative to nonhandling (NH; C. R. Pryce, D. Bettschen, N. I. Bahr, & J. Feldon, 2001). The present study demonstrates that both EH and ED adults exhibit enhanced active avoidance relative to NH adults. Fear-conditioned context and conditioned stimulus (CS) freezing were unaffected in both EH and ED, but stress hormone responses to the CS were reduced in EH males and ED females relative to NH. In the water maze, ED adults exhibited enhanced spatial learning and memory relative to NH.

Adrenocorticotropic Hormone↗
PubMed2005

Genetic analysis of learning and memory deficits in senescence-accelerated mouse (SAM).

Genetic analysis of learning and memory deficits (LMD) in senescence-accelerated mouse P8 (SAMP8) was performed by cross-mating SAMP8 and Japanese Fancy Mouse 1 (JF1). The incidence of LMD in the F2 generation showed a 3:1 segregation ratio of mice with LMD to normal mice, and the incidence of LMD in the backcross generation of the F1 to JF1 parental strain was in agreement with a 1:1 ratio of mice with LMD to normal mice. Estimation of the number of genes involved in the development of LMD using Wright's formula showed that at least two to four genes are involved. These results suggest that the inheritance of LMD is polygenically controlled and that there may be a single major gene, but this locus is not sex-linked. Moreover, hormonal influence on the development of LMD in SAMP8 females is of a genotype-dependent manner.

Aging↗
PubMed1999

The influences of sex, rearing environment, and neonatal choline dietary supplementation on spatial and nonspatial learning and memory in adult rats.

The potential facilitative effects of early environmental enrichment and perinatal choline chloride dietary supplementation on male and female adult rats' learning and memory were examined using a "stimulus-elicited investigative," and a social/observational learning-cued spatial memory paradigm. Male and female animals were either maintained in a standard lighted colony (SC) or were given supplementary exposure to a complex environment (EC) for 2 hr daily from 24-90 days of age. In each case, half of the animals were exposed to the choline supplementation both prenatally and postnatally for 24 days. In one paradigm, the 90-day-old EC rats were found to be significantly more responsive than SC rats to each change in the spatial relationships of objects contained in an open field. Neither sex nor early diet of the animals were much of a factor in the investigative behavior observed. In the second paradigm, the effects of the perinatal choline diet did interact with those of sex and postnatal environment to alter the impact of social/observational experience on the acquisition and memory of place in the water maze. The choline-treated EC males were the most influenced by their experience seeing a demonstrator swim to a platform location. The present study provides some further insight into the scope of the long-term functional enhancements produced by perinatal choline supplementation and EC in male and female animals and relates these effects to common modifications to targets of cholinergic basal forebrain systems.

Animals↗
PubMed2006

Effect of melatonin and vitamin E on diabetes-induced learning and memory impairment in rats.

Previous studies indicate that diabetes mellitus might be accompanied by a certain erosion of brain function such as cognitive impairment. The aim of this study was to examine and compare the effects of melatonin and vitamin E on cognitive functions in diabetic rats. Diabetes was induced in male albino rats via intraperitoneal streptozotocin injection. Learning and memory behaviors were investigated using a spatial version of the Morris water maze test. The levels of lipid peroxidation and glutathione were detected in hippocampus and frontal cortex. The diabetic rats developed significant impairment in learning and memory behaviors as indicated by the deficits in water maze tests as compared to control rats. Furthermore, lipid peroxidation levels increased and glutathione concentration decreased in diabetic rats. Treatment with melatonin and vitamin E significantly ameliorated learning and memory performance. Furthermore, both antioxidants reversed lipid peroxidation and glutathione levels toward their control values. These results suggest that oxidative stress may contribute to learning and memory deficits in diabetes and further suggest that antioxidant melatonin and vitamin E can improve cognitive impairment in streptozotocin-induced diabetes.

Animals↗
PubMed1995

The Drosophila learning and memory gene linotte encodes a putative receptor tyrosine kinase homologous to the human RYK gene product.

The linotte mutant was isolated on the basis of its learning and memory deficit. Interestingly, linotte individuals carrying a null mutation are viable, indicating that the linotte gene is not required for vital functions. We show here that the linotte gene encodes a putative receptor tyrosine kinase, homologous to the human protein RYK. These products are unique among receptor tyrosine kinases, since they possess a short extra cellular domain, and a modified intracellular catalytic domain. In particular, the subdomains directly involved in ATP binding and phosphotransfer reaction display remarkable variations. These results suggest that linotte is part of a novel signal transduction cascade involved in learning and memory.

Amino Acid Sequence↗
PubMed1999

Episodic memory and learning in patients with chronic schizophrenia.

This study explored the pattern of memory functioning in 58 patients with chronic schizophrenia and compared their performance with 53 normal controls. Multiple domains of memory were assessed, including verbal and non-verbal memory span, verbal and non-verbal paired associate learning, verbal and visual long-term memory, spatial and non-spatial conditional associative learning, recognition memory and memory for temporal order. Consistent with previous studies, substantial deficits in long-term memory were observed, with relative preservation of memory span. Memory for temporal order and recognition memory was intact, although significant deficits were observed on the conditional associative learning tasks. There was no evidence of lateralized memory impairment. In these respects, the pattern of memory impairment in schizophrenia is more similar in nature to that found in patients with memory dysfunction following mesiotemporal lobe lesions, rather than that associated with focal frontal lobe damage.

Adult↗
PubMed2006

Self-controlled visual discrimination learning of group-housed dwarf goats (Capra hircus): behavioral strategies and effects of relocation on learning and memory.

In most studies on animal learning, individual animals are tested separately in a specific learning environment and with a limited number of trials per day. An alternative approach is to test animals in a familiar environment in their social group. In this study, the authors--applying a fully automated learning device--investigated voluntary, self-controlled visual shape discrimination learning of group-housed dwarf goats (Capra hircus). The majority of the tested goats showed successful shape discrimination, which indicates the adaptive value of an effective learning strategy. However, in each group, a few individual goats developed behavioral strategies different from shape discrimination to get reward. Relocation impairs memory retrieval (probably by attention shifting) only temporarily for previously learnt shapes. The results demonstrate the usefulness of a self-controlled learning paradigm to assess learning abilities of social species in their normal social settings. This may be especially relevant for captive animals to improve their welfare.

Animals↗