Table 3.

Density of different pSer202 tau-immunoreactive structures in muskoxen prefrontal and parietal cortical layers

Individual	Block	Region	Neuropil	NTC	Neuron
Male	PFC	I	26.38	5.05	0.04
		II	24.15	4.66	0.35
		III	12.81	2.01	0.09
		IV–VI	15.26	0.83	0.19
		WM	2.58	0.14	0.02
	Parietal	I	46.56	0.16	0
		II	31.58	0.95	0
		III	15.74	0.81	0
		IV–VI	13.72	0.48	0.1
		WM	2.67	0	0
Middle-aged female	PFC	I	838.06	102.55	0.3
		II	606.09	76.88	5.06
		III	386.74	46.31	1.56
		IV–VI	310.93	36.71	1.66
		WM	84.21	7.8	0
	Parietal	I	68.31	0.82	0
		II	31.34	0.72	0.18
		III	19.11	0.54	0
		IV–VI	24.9	0.39	0
		WM	3.81	0.04	0
Old female	PFC	I	14,345.69	380.7	0
		II	9049.63	856.97	0
		III	6385.27	349.36	6.24
		IV–VI	6306.02	292.55	24.38
		WM	1428.71	91	0
	Parietal	I	164.73	6.13	0
		II	239.71	12.51	0.48
		III	74.79	3.58	0.05
		IV–VI	27.55	2.02	0
		WM	7.81	0.14	0.07

Brain samples were taken from the prefrontal and parietal cortex and immunostained for pSer202 tau. An exhaustive count of pSer202 tau-immunoreactive neuropil threads, neuritic thread clusters, and neurons was performed using StereoInvestigator on ten slices, each 500 µm apart and adjusted for volume (cm³) of each layer. Exhaustive counts are reported in Table S1. Data represent estimated population/cm³ and are adjusted by volume

WM white matter, PFC prefrontal cortex, NTC neuritic thread clusters