either side of the perfusion stream would provide a barrier to maintain the isolation of the fluid microenvironments– this was indeed the case. In addition, the Alexa Fluor 488 dye was restricted only to the postsynaptic compartment. The Alexa Fluor 633 dye was detected only in the presynaptic compartment and the microgrooves proximal to the presynaptic compartment. These data indicate that the μLP chamber can be used to pharmacologically manipulate each of these compartments simultaneously.