Alpha herpesvirus exocytosis from neuron cell bodies uses constitutive secretory mechanisms, and egress and spread from axons is independent of neuronal firing activity
Fig 6
Neuronal activity does not correlate with PRV spread from neuron to neuron.
(A) Schematic of modified Campenot tri-chamber. SCG neurons were seeded in the left soma compartment and extended axons under the chamber walls to the right neurite compartment. Recipient SCG neurons were then added to the neurite compartment. PRV infection was initiated in the soma compartment, and neurons were treated with 4μM TTX, or pulses of 55mM KCl, or untreated, as indicated. (B) Recipient neurons in the right neurite chamber do not penetrate the left soma compartment. Lipophilic fluorescent dye, DiD (blue), was added to the soma chamber, and chambered cultures were imaged by live-cell fluorescence microscopy. Out of many chambers, only a single DiD-labeled cell body was detected (zoom). Scale bars represent 0.5 mm (left) and 30 μm (zoom). (C) A defective leaky chamber demonstrates extensive DiD-labeling of cells, demonstrating that these imaging parameters can readily detect DiD-positive cells in the neurite chamber. (D) Tiled image of neurite chambers (area indicated by red box in Fig 2A). Scale bar represents 1mm. (E) Mean relative mRFP-VP26 capsid fluorescence of entire neurite chambers over time. Mean of 8 independent experiments. Shaded area represents standard deviation. No significant difference (p>0.05) at all time points.