FIG. 1.

Setup of the trichamber system for the assay of neuron-cell-neuron spread of infection. SCG neurons were dissected and plated in both the S and the N compartments. After the appropriate time (4 to 7 days), PK15 cells were plated in the M compartment. Twenty-four hours after plating, methocel was added to the M compartment and infectious virions were added to the S compartment to initiate infection of the neurons. The infection then spreads from the neurons in the S compartment to the PK15 cells in the M compartment. Since the neurons from the N compartment also extend neurites into the M compartment, the infected PK15 cells will transmit the infection to the neurons in the N compartment.