Protocol to count the number of noradrenergic neurons in mouse locus coeruleus by unbiased stereology

Loss of noradrenergic (NE) neurons in the locus coeruleus (LC) occurs in both Alzheimer's disease (AD) and Parkinson's disease (PD): pharmacological therapies aimed at neuroprotection in brain area are needed. Here, we present a protocol for assessing the absolute number of NE neurons in the mouse LC by unbiased stereological counting. We describe steps for preparing the brain slices, delineating the region of interest, counting the neurons, and using the Stereo Investigator software. For complete details on the use and execution of this protocol, please refer to Regoni et al.1