Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “learning and memory”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,171 records · Page 65Linked to original sources
PubMed1998

Spatial learning and memory induce up-regulation of nitric oxide-producing neurons in rat brain.

Changes of nitric oxide (NO)-producing neurons in the brain following learning is not yet clear. In present study, nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry and neuronal NO synthase (nNOS) immunohistochemistry were used to detect NOS neurons in rat brain. Results demonstrated that expression of NOS neurons in dentate gyrus and frontal cortex was significantly increased after a water-rewarded spatial alternation task when compared with that after sham training. The elevated expression of NOS neurons occurred not only in the earlier memory stage, but also in the later memory stage. In addition, the expression location and cell counts of NOS neurons in dentate gyrus and frontal cortex with NADPH-d staining or nNOS immunoreactivity resembled each other, but the cell counts of NADPH-d positive neurons were a little more than those of nNOS immunoreactive neurons. The involvement of NO in the processes of spatial learning and memory is further suggested.

Animals↗
PubMed1987

Near-total loss of 'learning' and 'memory' as a result of combined cholinergic and serotonergic blockade in the rat.

Previous work has indicated that activation of the cerebral cortex (i.e. elicitation of low-voltage fast activity in the neocortex and rhythmical slow activity in the hippocampus) is dependent on corticipetal cholinergic and serotonergic projections. Treatment with a combination of p-chlorophenylalanine (an inhibitor of the synthesis of serotonin) plus atropine or scopolamine (muscarinic cholinergic antagonists) can suppress all cerebral activation. In this paper, the behavioral effects of single or combined blockade of cholinergic and serotonergic neurotransmission were studied using a shock avoidance test, an open field test, a swim-to-platform test, a hypothalamic self-stimulation test and a test of grooming behavior. The results show that blockade of cerebral activation produces a condition analogous to global dementia but does not produce sleep or coma. The hypothesis that cholinergic and serotonergic neurotransmission provides a basis for learning and memory is discussed critically.

Animals↗
PubMedDate not supplied

Mitogen-activated protein kinase/extracellular signal-regulated kinase induced gene regulation in brain: a molecular substrate for learning and memory?

The mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) pathway is an evolutionarily conserved signaling cascade involved in a plethora of physiological responses, including cell proliferation, survival, differentiation, and, in neuronal cells, synaptic plasticity. Increasing evidence now implicates this pathway in cognitive functions, such as learning and memory formation, and also in behavioral responses to addictive drugs. Although multiple intracellular substrates can be activated by ERKs, nuclear targeting of transcription factors, and thereby control of gene expression, seems to be a major event in ERK-induced neuronal adaptation. By controlling a prime burst of gene expression, ERK signaling could be critically involved in molecular adaptations that are necessary for long-term behavioral changes. Reviewed here are data providing evidence for a role of ERKs in long-term behavioral alterations, and the authors discuss molecular mechanisms that could underlie this role.

Animals↗
PubMed1998

Understanding neural interactions in learning and memory using functional neuroimaging.

Neuroimaging methods such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) provide a unique opportunity to explore activity across the entire human brain in many different behaviors. An important additional feature is the ability to examine interacting neural systems using methods that focus on the covariances of activity. Two of these methods, partial least squares and structural equation modeling, are presented with specific examples. Shifting prefrontal and limbic interactions were observed in a working memory task for faces. In an episodic memory retrieval study, the activity of right prefrontal cortex was related to either memory search or successful retrieval depending on its interactions with other brain regions. This latter observation implies that regional activity must be evaluated within the neural context in which it occurs. The general hypothesis that learning and memory are emergent properties of network interactions is discussed, emphasizing that a region can play a different role across many functions and that role is governed by its interactions with anatomically related regions.

Animals↗
PubMed1999

Baclofen and AII 3-7 on learning and memory processes in rats chronically treated with ethanol.

The aim of this study was to determine the possible influence of baclofen, an agonist of the GABA(B) receptor on behavioral activity (recall, acquisition of conditioned reflexes) of angiotensin II fragment 3-7 (AII 3-7) in rats chronically treated with ethanol. Long-term (9 weeks) ethanol intoxication profoundly impaired learning and memory processes in all tests used. The GABA(B) receptor agonist baclofen (0.75 mg/kg i.p.) did not influence exploratory and motor activity in the control rats, but we observed a tendency (without significance) to decrease the psychomotor activity in the alcohol-intoxicated groups of animals, when it was injected together with AII 3-7 (2 microg i.c.v.). Baclofen did not influence the retrieval process in the passive avoidance recall, and when it was given together with AII 3-7 did not change the positive action of this fragment in control groups, but significantly enhanced its action in the animals chronically treated with ethanol. Baclofen showed significant improvement of acquisition in the active avoidance test only in the alcohol-intoxicated groups. Baclofen, injected together with AII 3-7, yielded important attenuation action of AII 3-7 in the control groups in the first 3 days of test, but did not produce any changes during the fourth and fifth day of the experiment. Baclofen did not provoke any changes in activity of AII 3-7 (when it was injected together) in the acquisition of the active avoidance test in the alcohol-intoxicated groups of animals.

Analysis of Variance↗
PubMed1993

Effects of exogenous gangliosides on learning and memory in rats.

After 10 or more consecutive daily injections (I.P. 50 mg/kg for developing, adult and aged, 2.5 mg/mouse for neonatal) of total bovine gangliosides, rats were trained to perform the discrimination tasks. The results show that gangliosides can enhance the learning ability and memory retention in rats at different ages.

Aging↗
PubMed2003

Molecular mechanisms of learning and memory.

Memory is the process by which organisms are able to record their experiences, and use this information to adapt their responses to the environment. As such, it is vital for survival. In recent years, the development of spatially and temporally selective techniques for the regulation of gene expression has allowed the molecular details of this process to emerge. Here we review the molecular mechanisms thought to underlie memory acquisition and storage, as well as discuss recent evidence regarding the mechanisms of subsequent memory consolidation.

Animals↗
PubMed1989

Effect of inhalation of insecticide spray on learning and memory in rats.

Acute exposure to insecticide (Baygon-spray; 5 ml/animal/5 min) inhalation in rats did not affect the learning process but produced a significant loss of memory (P less than 0.01 less than 0.001) whereas chronic exposure (one exposure per day for three weeks) produced a significant delay in learning (P less than 0.05) and memory (P less than 0.01). Acetylcholinesterase activity in brain after acute and chronic exposure declined significantly (P less than 0.01) during the learning process but returned to normal after 24 hr.

Acetylcholinesterase↗
PubMed1997

Object-recognition and spatial learning and memory in rats prenatally exposed to ethanol.

Prenatal ethanol exposure can produce cognitive and behavioral impairments. In the present study, rats from prenatal ethanol (E), pair-fed (PF), and ad libitum-fed control (C) treatment conditions were tested on the object-recognition delayed-nonmatching-to-sample (DNMS) task with nonrecurring items and on the spatial-navigation Morris water maze task. In Experiment 1, there were no significant differences among groups in object-recognition learning and memory, distractibility, or response perseveration on the DNMS task. In Experiment 2, the same rats were tested in the water maze; E rats took significantly longer to learn the task than did the PF or C rats. These data suggest that the mechanisms underlying spatial cognitive abilities are more vulnerable to the teratogenic effects of prenatal ethanol exposure than those underlying object-recognition abilities.

Animals↗
PubMed1989

Video-task assessment of learning and memory in macaques (Macaca mulatta): effects of stimulus movement on performance.

Effects of stimulus movement on learning, transfer, matching, and short-term memory performance were assessed with 2 monkeys using a video-task paradigm in which the animals responded to computer-generated images by manipulating a joystick. Performance on tests of learning set, transfer index, matching to sample, and delayed matching to sample in the video-task paradigm was comparable to that obtained in previous investigations using the Wisconsin General Testing Apparatus. Additionally, learning, transfer, and matching were reliably and significantly better when the stimuli or discriminanda moved than when the stimuli were stationary. External manipulations such as stimulus movement may increase attention to the demands of a task, which in turn should increase the efficiency of learning. These findings have implications for the investigation of learning in other populations, as well as for the application of the video-task paradigm to comparative study.

Animals↗
PubMed1980

Learning and memory deficits in alcoholics.

Alcoholics abstinent at least 4 weeks took longer to learn a list of noun pairs than did nonalcoholic controls, yet were able to remember as well as the controls when provided with mnemonics.

Alcoholism↗
PubMed1989

The neurobiology of learning and memory.

The study of memory is a great challenge, perhaps the greatest in biological sciences. Memory involves changes in a tiny fraction of an extremely large pool of elements, a conclusion that makes the task of finding those changes using current technologies formidable. What can be done about this roadblock to neurological investigations of learning? One response that has become particularly productive in recent years is to study learning or learning-like phenomena in relatively simple "model" systems. The idea is to extract basic principles from these models in which molecular and anatomical details can be studied and then to use these in analyzing learning in higher regions of the brain. In this article we discuss current progress and emerging concepts derived from the simple system approach using animal models.

Animals↗
PubMedDate not supplied

Beneficial effects of aged garlic extract on learning and memory impairment in the senescence-accelerated mouse.

We first investigated the effect of aged garlic extract (AGE) on the longevity and learning performance in the Senescence-Accelerated Mouse (SAM). A solid diet containing AGE was fed after two months of age. An AGE treatment increased the survival ratio of the SAMP8. Moreover, the preparation ameliorated the memory acquisition deficit and the memory retention impairment of the SAMP8 at 10 months old. The learning improvement was also confirmed in a spatial cognition test. We next studied the effect of AGE on another strain of the SAM, SAMP10. Although the life span prolongation was not observed in the AGE-treated SAMP10, the preparation improved the grading score, an index of aging. A surprising result was obtained by measuring the brain size. The degree of shrinkage in the frontal cerebrum was 2-9% in the SAMP10. Chronic ingestion of AGE prevented this atrophy and kept the brain size at the control level. These results suggest that AGE has an antiaging effect on the SAM.

Aging↗