NITRIC-OXIDE SYNTHASE IMMUNOREACTIVITY DISTINGUISHES A SUBPOPULATION OF GABA-IMMUNOREACTIVE NEURONS IN THE VENTROBASAL COMPLEX OF THE CAT

This study describes the presence of nitric oxide synthase (NOS-ir) im munoreactive neurons in the thalamic ventrobasal complex of the cat. N OS-it is co-localized with gamma-aminobutyric acid (GABA-ir) in a subs et of small neurons identified as local circuit neurons in previous st udies. The double labeled neurons are further identified by a larger s oma diameter when compared to GABA-ir only neurons. All NOS-ir somata exhibit GABA-ir but none exhibit immunoreactivity to calbindin.