Next, cells are inoculated with {TAIL ~ neurotropic virus} under conditions that restrict {HEAD ~ viral propagation} 
Next , cells are inoculated with { TAIL ~ neurotropic virus } under conditions that restrict { HEAD ~ viral propagation }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD