Amphetamine tolerance is caused by excess Ca++ influx through the NMDA receptor gated calcium channels on the outer membranes of the dopamine cells bodies in the ventral tegental area, one of two areas in the brain with concentrations of dopamine producing neurons.
As alluded to above, taking an appropriate NMDA (partial) antagonist will prevent the development of a tolerance for the effects of an amphetamine or amphetamine-like stimulant. Also, by preventing excess Ca++ influx into the neuron, an NMDA antagonist will prevent associated brain alterations and damage (excitotoxicity).
Studies have indicated that amphetamine tolerance is prevented by exogenous or endogenous agents that are able to inhibit excess Ca++ influx into the neuron through the gated calcium channels on the neuronal membrane that have NMDA subtype glutamate receptors.Glutamate , the body’s major excitatory neurotransmitter, opens the gated calcium ion channels upon attaching to the NMDA receptor. A number of other receptors are also expressed on these calcium channels, which, when stimulated, either facilitate or inhibit glutamate’s action.
It is also important that agents that inhibit calcium channel activity not also cause deficient Ca++ influx. For example, ketamine is a full NMDA receptor antagonist, that prevents excess Ca++ influx and amphetamine tolerance. But being a full NMDA antagonist, ketamine in excessive doses results in deficient Ca++ influx. This could be one of the reasons it leaves K-user in a state of disassociation.
taken from
http://www.dr-bob.org/babble/20031015/msgs/270735.html
the same goes for opiates. you need an agonist in order to reduce tolerance as excess c++ molecules are stopped from entering the neurotransmitters, which is what causes the tolerance to begin with. it wouldn't exactly reverse a tolerance but it would prevent it from building up.
now back on topic, d-aspartic acid stimulants nmda receptors but only ever so slightly. you'd surely need an incredibly large dose in order to prevent the tolerance which would not be economical or healthy i presume. although all methods are not exactly healthy. i guess it could work, but you need a measure as to how much it effects the nmda receptor first.