Modern science has officially proved that smoking bananas, can produce similar symptoms/effects to smoking marijuana. There are certain sugars and related compounds that exist in both bananas and marijuana. Just saying.
In Marijuana, the primary chemical that gets user's high when smoked is Delta-9-tetrahydrocannabinol (Delta-9-THC). When consumed, it produces psychoactive effects on the brain, and releases dopamine to the brain, which should be noted that dopamine is not the cause of the psychoactive effects of Marijuana.
If bananas can produce the same psychoactive effects on the brain as Marijuana, it would have to have chemicals similar to Delta-9-tetrahydrocannabinol. Known chemicals that produce the same effects as Marijuana are found in drugs like K2, commonly referred to as it's street name "Spice" which clearly says "NOT FOR HUMAN CONSUMPTION" which only leads me to believe that these chemicals are not found in the very edible food, bananas.