SNCA and Parkinson disease: This somatic free and loosely bound zinc may also make cells in the anterior olfactory nucleus more vulnerable to the aggregation of alpha-synuclein in early PD, especially within lipofuscin: alpha-synuclein-positive particles and small Lewy bodies have been detected within lipofuscin pigment in the PD brain stem94, although this has not been described in the olfactory bulb.