Table 2.

First appearance of astroglial markers in radial glial cells and astrocytes in developing human brain

Marker	Developmental stage*	Location	Developmental stages evaluated*	Location evaluated	References
GFAP
Radial glial cells	5.5–6 wpc (5.5–6 gw)?†	Lateral telencephalic wall	5.5–23 wpc? (5.5–23 gw)	Lateral telencephalic wall	Zecevic (2004)
	6–8 wpc (8–10 gw)?	Cerebellum	6 wpc–12 years (8 gw to 12 years)?	Cerebellum	Yachnis et al. (1993)
	9 wpc (9 ow)	Fimbria, dentate gyrus, hippocampus	5.5–20 wpc (5.5–20 ow)	Fimbria, dentate gyrus and hippocampus	Stagaard Janas et al. (1991b)
	10 wpc (10 ow)	Frontoparietal cerebrum	10–19 wpc (10–19 ow)	Frontoparietal cerebrum	Antanitus et al. (1976); Choi & Lapham (1978)
	11 wpc (13 gw)		7–38 wpc (9–40 gw)	Cortex	Middeldorp et al. (2010)
	13 wpc (15 gw)	VZ and SVZ around the third ventricle (radial glial cells?)	5–23 wpc (7–25 gw)	Cerebrum	Sasaki et al. (1988)
Astrocytes	14 wpc (14 ow)	Fimbrio‐dentate border, hippocampus IZ	4.5–20 wpc (4.5–20 ow)	Fimbria, dentate gyrus and hippocampus	Stagaard Janas et al. (1991a,1991b)
	14 wpc (16 gw)	Mainly SVZ in motor cortex	14–22 wpc† (16–24 gw)	Motor cortex	Aquino et al. (1996)
	15/17 wpc (17 wpc/gw)?		16–40 wpc/gw? (16–40 wpc/gw)	Cortex, WM and GM	El‐Khoury et al. (2006)
	17 wpc (17 gw)?	SVZ (and few in CP)	5.5–23 wpc? (5.5–23 gw)	Frontal and/or occipital cortex	Zecevic (2004)
	18 wpc (20 gw)	IZ	5–23 wpc (7–25 gw)	Cerebrum	Sasaki et al. (1988)
	Midgestation	CP		Human forebrain	Howard et al. (2008)
S100B
Radial glial cells	12 wpc (12 ow)	Fimbria (at 13 ow also in fornix)	5.5–20 wpc (5.5–20 ow)	Fimbria, dentate gyrus and hippocampus	Stagaard Janas et al. (1991b)
	13 wpc (15 gw)	VZ and SVZ around the third ventricle (radial glial cells?)	5–23 wpc (7–25 gw)	Cerebrum	Sasaki et al. (1988)
Astrocytes	6.5 wpc (6.5 ow)	Brainstem	4.5–20 wpc (4.5–20 ow)	Brainstem	Stagaard Janas et al. (1991a)
	9.5 wpc (9.5 ow)	Fimbria, hippocampus and neocortex	4.5–20 wpc (4.5–20 ow)	Fimbria, dentate gyrus, hippocampus and neocortex	Stagaard Janas et al. (1991a)
	10 wpc (12 gw)?	All layers of hippocampus	10–38 wpc (12–40 gw)?	Hippocampus, entorhinal cortex and occipital cortex	Tiu et al. (2000)
	11 wpc (11 ow)	Fimbria, dentate gyrus and hippocampus	5.5–20 wpc (5.5–20 ow)	Fimbria, dentate gyrus and hippocampus	Stagaard Janas et al. (1991b)
	15/17 wpc (17 wpc/gw)?		16–40 wpc/gw? (16–40 wpc/gw)	Cortex, WM and GM	El‐Khoury et al. (2006)
AQP4
Radial glial cells	Not found	Not found	Not found	Not found	Not found
Astrocytes	12 wpc (14 gw)	End‐feet of astrocytes restricted to dorsal and ventral hippocampus	12–38 wpc (14–40 gw)	Whole brain?	Gömöri et al. (2006)
	15/17 wpc (17 wpc/gw)?	GM > Cortex, WM and	16–40 wpc/gw? (16–40 wpc/gw)	Cortex, WM and GM	El‐Khoury et al. (2006)
	19–20 wpc (21–22 gw)	Neocortex	12–38 wpc (14–40 gw)	Whole brain?	Gömöri et al. (2006)
CHI3L1 (YKL‐40)
Radial glial cells	5–6 wpc	Few neuroepithelial cells/radial glial cells	5–20 wpc	Forebrain	Bjørnbak et al. (2014)
	12 wpc	VZ (At 11 wpc only VZ in fimbria is immunoreactive for YKL‐40)	8–20 wpc	Forebrain	Brøchner & Møllgård (2016)
Astrocytes	20 wpc	Fimbria	5–20 wpc	Forebrain	Bjørnbak et al. (2014)
	15 wpc	SVZ in antihem (PSB)	8–20 wpc	Forebrain	Brøchner & Møllgård (2016)

CP, cortical plate; GM, germinal matrix; gw, gestational weeks; IZ, intermediate zone; ow, ovulation weeks; wpc, weeks post conception; PSP, pallial–subpallial boundary; SVZ, subventricular zone; WM, white matter.

^*Approximated wpc (weeks post conception), original described developmental stage in brackets.

^†Two monoclonal GFAP antibodies yielded different results: monoclonal GFAP (Dako) was not expressed prior to 9–10 gw (gw in Zecevic, 2004; may be equivalent to wpc, therefore this is 9–10 wpc), whereas monoclonal GFAP (Chemicon) labeled radial glial cells at 6 gw (most probably 6 wpc).

^‡GFAP was not detectable in prefrontal cortex before 14 wpc (16 gw) as evaluated by quantitative immunoblotting.