The NMDA antagonist MK-801 affects nonspatial learning in preweanling rats.
The N-methyl-D-aspartate (NMDA) subtype of the excitatory amino acid receptor has been implicated in several kinds of learning and memory, as well as in long-term potentiation (LTP), a putative cellular mechanism for learning and memory. This experiment examined the role of the NMDA receptor in patterned single-alternation (PSA) learning in preweanling rats following intraperitoneal injections of 0.05 mg/kg MK-801, a selective NMDA antagonist. MK-801 significantly inhibited PSA at both 60-s and 30-s intertrial intervals (ITIs), and attenuated, but did not block, learning at 8-s ITI. These results are compared with effects on PSA, a form of nonspatial, memory-based learning, observed after early postnatal exposure to alcohol, infant hippocampal lesions, and infant exposure to X-irradiation, and they add strongly to these earlier demonstrations of the role of the hippocampus in learning and memory that is clearly nonspatial and non-cognitive-map-related.
Highfield
D A
DA
Department of Psychology, University of Texas at Austin 78712, USA.
Nixon
K
K
Amsel
A
A
D000818:Animals; D000831:Animals, Newborn; D001070:Appetitive Behavior / Q000187:drug effects / Q000502:physiology*; D001931:Brain Mapping; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D011939:Mental Recall / Q000187:drug effects / Q000502:physiology*; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009949:Orientation / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000502:physiology*
D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D016291:Dizocilpine Maleate