Stage 2

In stage 2 the inclusion body pathology remains confined to the medulla oblon-gata and pontine tegmentum. The lesions in the dorsal motor nucleus of the vagal nerve and intermediate reticular zone increase (Fig. 22) and the disease process passes beyond the limits of these nuclei to include: (1) portions of the lower raphe nuclei, particularly the great raphe nucleus (rm; Fig. 13 a,b, and c–e), (2) magnocellular portions of the reticular formation (gigantocellular nucleus, gig; Fig. 13a), and (3) catecholaminergic melanized neurons of the coeruleus—sub-coeruleus complex (equivalent to the rodent A6 and A7 groups) (Table 2; Fig. 14a and b–d). The appearance of LNs precedes the development of LBs in each of these