Reptilian dorsal column nucleus lacks GAD immunoreactive neurons

Brains of reptiles, Caiman crocodilus, were processed by standard immunocytochemical methodology using a polyclonal antibody to glutamic acid decarboxylase (GAD) as well as several monoclonal antibodies to GAD. No neurons immunoreactive for GAD, GAD(+), were observed in the dorsal column nucleus, although GAD(+) puncta were seen. These findings suggest that in Caiman, the dorsal column nucleus, like the dorsal thalamus, lacks local circuit neurons.