FIG. 4.

Neurons cultured up to 6 days extend neurites into the M but not into the N compartment (comp). (A) SCG neurons were cultured in both S and N compartments. After 6 days, we plated PK15 cells in the M compartment of half the chambers used in the experiment. Twenty-four hours after we plated the PK15 cells, we infected the neurons in S compartments with PRV 151, PRV 152, or GS442. At 24 h postinfection, the total contents of the S and N compartments were harvested and titers were determined for PK15 cells. Three chambers were used in each type of infection. The circle beside each data set represents the average value for that set of data. The standard deviations for the S compartment are ±5.8 × 10⁴ for cells with PK151 (+PK151), ±2.4 × 10⁴ for +PK152, ±4 × 10¹ for +PK442, ±8.8 × 10⁴ for cells without PK151 (−PK151), ±4.2 × 10⁵ for −PK152, and ±2.3 × 10¹ for −PK442; those for the N compartment are 0 for +PK151 and ±5.1 × 10⁴ for −PK151. (B) SCG neurons were cultured as described above, with (c to e, h to j, and m to o) or without (a, b, f, g, k, and l) PK15 cells in the M compartment. Neurons in the S compartment were then infected with PRV 151 (a through e), PRV 152 (f through j), or PRV GS442 (k through o). The expression of EGFP in infected cells was visualized live with an epifluorescence microscope. Images were obtained from the S compartment (a, f, k, c, h, and m), M compartment (d, i, and n), and N compartment (b, g, l, e, j, and o). −, absence of; +, presence of.