Translational NeuroImaging of the CNS: Novel Pathways to Drug Development

In vivo imaging of the neuronal nicotinic receptor β2 subtype. Knock-out (KO) and wild-type (WT) mice were imaged using the [123I]5-IA SPECT tracer. Specificity of target engagement of the PET/SPCET tracer can be assessed using genetically modified mice. We examined the binding specificity of [¹²³I]5-IA to neuronal nicotinic receptor subtypes in KO (n= 4) and WT (n=2) mice. Fifty minutes after the infusion of 0.5mCi tracer, each mouse was imaged for forty-five minutes. Representative images clearly show the reduction of tracer uptake in KO mice, and quantitative region-of-interest analysis indicated significant decreases in binding activity at both prefrontal cortex (PFC) and thalamus.