NMDA receptors is related to memory, specifically with LTP (long-term potentiation, long-term potentiation). NMDA is an amino acid N-methyl-D-aspartic normal neurotransmitter. The NMDA receptor has the interesting property that it is responsible for the creation of memory traces in the brain and particularly in the memory center - hippocampus.
NMDA receptor AND gate and the recorder memory traces in the brain
NMDA receptor functions as an AND gate with three inputs (one electric and two chemical) and two outputs (one electric and one chemical). Electrical input voltage at the membrane of the neuron. Chemical inputs are synaptic NMDA signal and the signal of glycine / serine. Electric output is depolarization (postsynaptic) neuron, chemical output is to increase the levels of calcium, which causes the creation of its own memory trace. To remember (association) of the various inputs will only arrive when the neuron into two sufficiently strong signals simultaneously. For example, if you take pavlovovského dog and chow or bell alone will not cause the creation of conditioned reflex. Only offers if the animal chow while ringing and memory neuron that is activated by taste sensations and sound simultaneously executes its AND function, the NMDA receptors drains calcium in and amplify synaptic strength of the sound stimulus, so the dog then drools even just ringing. Who shakes his head, he can make an attempt on himself - such association blinking and bells. (Tell a friend let you at irregular intervals blowing through a straw on the cornea, while always rings a bell, you'll see that after about fifteen repetitions will unconsciously blinking stupidly at the sound of the bell.)