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-sec and 30-sec intervals (ITIs). and attenuated, but did not block Iearning at 8-sec . 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 demonstrartions of the role of the hippocampus in learning and memory that is clearly nonspatial and non-cognitive-map-related. (PsycINFO Database Record (c) 2010 APA, all rights reserved)