ABSTRACT

The hippocampus of the rat and associated cortex is thought to provide the rat with a representation of the space around it and its location within it. This is the cognitive map hypothesis and it has several postulates. The hippocampal formation is folded archaecortex consisting of the dentate gyrus and the cornu ammonis–collectively termed the hippocampus–plus the subiculum. The hippocampus also harbors inhibitory interneurons that are GABAergic. A core idea of contemporary neuroscience is that learning occurs by changes in the strength of synapses. Several mechanisms to bring about synaptic modifications are known which either increase synaptic weighting, long-term potentiation (LTP); or decrease synaptic weighting, long-term depression. LTP can be either associative or nonassociative. There is some dispute about whether LTP is a cellular substrate of learning. Preventing N-methyl-D-aspartate receptors from functioning not only blocks induction of LTP, it also prevents some types of learning.