Figure 5.

There is a good correlation between NMDA-induced increase in extracellular cGMP and the ability to learn the Y-maze task. Individual data for 7-mo-old males and females are plotted. The function of the glutamate–NO–cGMP pathway is expressed as the increase in cGMP induced by administration of NMDA, i.e., the increase in cGMP in fractions 7–9 of Figure 2. There is a negative and significant (r = −0.769; P = 0.0013) correlation between the function of the pathway and the number of trials required to learn the task. A higher number of trials means a lower learning ability. This means that there is a direct correlation between the function of the pathway and learning ability: A higher function of the pathway correlates with higher learning ability.