Conditional learning in aged rats: evidence of hippocampal and prefrontal cortex impairment. 1992

G Winocur
Department of Psychology, Trent University, Peterborough, Ontario, Canada.

Groups of normal old rats and young adult rats were administered a test of conditional discrimination learning in which different visual stimuli were associated with responses to different levers. Initially, rats were tested in a zero-delay condition in which they selected their responses in the presence of the conditional stimuli. They were later tested at 5- and 15-s delays between stimulus presentation and the appearance of the levers. Old rats were impaired in learning the basic conditional discrimination, a test thought to be sensitive to frontal lobe dysfunction. Age differences increased with the length of the interval, revealing a time-dependent memory loss that was attributed to impaired hippocampal function.

UI MeSH Term Description Entries
D007858 Learning Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge. Phenomenography
D008297 Male Males
D012055 Reinforcement Schedule A schedule prescribing when the subject is to be reinforced or rewarded in terms of temporal interval in psychological experiments. The schedule may be continuous or intermittent. Reinforcement Schedules,Schedule, Reinforcement,Schedules, Reinforcement
D002540 Cerebral Cortex The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions. Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
D003216 Conditioning, Operant Learning situations in which the sequence responses of the subject are instrumental in producing reinforcement. When the correct response occurs, which involves the selection from among a repertoire of responses, the subject is immediately reinforced. Instrumental Learning,Learning, Instrumental,Operant Conditioning,Conditionings, Operant,Instrumental Learnings,Learnings, Instrumental,Operant Conditionings
D004192 Discrimination, Psychological Differential response to different stimuli. Discrimination, Psychology,Psychological Discrimination
D005625 Frontal Lobe The part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus. Brodmann Area 8,Brodmann's Area 8,Frontal Cortex,Frontal Eye Fields,Lobus Frontalis,Supplementary Eye Field,Area 8, Brodmann,Area 8, Brodmann's,Brodmanns Area 8,Cortex, Frontal,Eye Field, Frontal,Eye Field, Supplementary,Eye Fields, Frontal,Frontal Cortices,Frontal Eye Field,Frontal Lobes,Lobe, Frontal,Supplementary Eye Fields
D006624 Hippocampus A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation. Ammon Horn,Cornu Ammonis,Hippocampal Formation,Subiculum,Ammon's Horn,Hippocampus Proper,Ammons Horn,Formation, Hippocampal,Formations, Hippocampal,Hippocampal Formations,Hippocampus Propers,Horn, Ammon,Horn, Ammon's,Proper, Hippocampus,Propers, Hippocampus,Subiculums
D000375 Aging The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time. Senescence,Aging, Biological,Biological Aging
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia

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September 2000, The Journal of neuroscience : the official journal of the Society for Neuroscience,
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