We quantified the binding potentials (BP_ND) of [¹¹C]yohimbine binding in rat brain to alpha-2 adrenoceptors to evaluate [¹¹C]yohimbine as an in vivo marker of noradrenergic neurotransmission and to examine its sensitivity to the level of noradrenaline. Dual [¹¹C]yohimbine dynamic positron emission tomography (PET) recordings were applied to five Sprague Dawley rats at baseline, followed by acute amphetamine administration (2 mg/kg) to induce elevation of the endogenous level of noradrenaline. The volume of distribution (V_T) of [¹¹C]yohimbine was obtained using Logan plot with arterial plasma input. Because alpha-2 adrenoceptors are distributed throughout the brain, the estimation of the BP_ND is complicated by the absence of an anatomic region of no displaceable binding. We used the Inhibition plot to acquire the reference volume, V_ND, from which we calculated the BP_ND. Acute pharmacological challenge with amphetamine induced a significant decline of [¹¹C]yohimbine BP_ND of ∼38% in all volumes of interest. The BP_ND was greatest in the thalamus and striatum, followed in descending order by, frontal cortex, pons, and cerebellum. The experimental data demonstrate that [¹¹C]yohimbine binding is sensitive to a challenge known to increase the extracellular level of noradrenaline, which can benefit future PET investigations of pathologic conditions related to disrupted noradrenergic neurotransmission.