The development and distribution of α-bungarotoxin binding sites in rat tectal transplants

The development and distribution of α-bungarotoxin (α-BTX) binding sites in tectal grafts was examined autoradiographically using the radioligand [¹²⁵I]-α-BTX binding was observed in localized areas within grafts; these areas corresponded to regions which contained high acetylcholinesterase activity and received retinal input. Receptor differentiation also occurred in the absence of specific host afferents. The graft data show that, as in normal superior colliculus, development of high α-BTX binding is limited to areas containing presumptive superficial layer cells.