I’m been looking into another line of research…the N-methyl-D-aspartic acid (NMDA) system. This system is associated with excitation (in general). Examples of NMDA system “excitors” include glumate (as in MSG – monosodium glutamate). But don’t rush out and start eating Chinese food just yet. The glutamate has to reach your brain for it to support an erection.

Here are some articles on this subject, pertaining to rat research: (LINK), (LINK), and (LINK). The last one involves injecting NMDA directly into the brain. I don’t recommned this!