Table 3.

Developmental expression of MK and pleiotrophin (PTN) in the rat brain.

	Location	Embryonic (E) or postnatal (P) days	PTN expression	MK expression	References
Prenatal cerebral cortex	Ventricular zone	E10	⇧	⇧ ⇧	(4)
	Ventricular zone	E14	⇧ ⇧	⇧ ⇧
	Preplate	E14	⇧	⇧ ⇧
	Ventricular zone and intermediate zone	E17	⇧ ⇧ ⇧	⇧ ⇧ ⇧
	Subplate	E17	⇧ ⇧	⇧ ⇧
	Cortical plate	E17 and E18	⇧ ⇧	⇧ ⇧
Postnatal cerebral cortex	Choroid plexus	P7	Not detected	⇧ ⇧ ⇧	(4)
	Corpus callosum	P7	⇧ ⇧ ⇧	Not detected
	Cortical plate, marginal layer, and layer V	P1	⇧ ⇧ ⇧
	Layer VI	P1	⇧ ⇧
	Layers I, III, and IV	P7	⇧ ⇧ ⇧
	Layers II, V, and VI	P7	⇧ ⇧
	Layers I, II, III, V	P14	⇧ ⇧ ⇧
	Layer IV and VI	P14	⇧ ⇧
Postnatal cerebellum	PLZ, PM, ML and PCL	P1	⇧ ⇧ ⇧	⇧	(3)
	EGL, ML and PCL and WM	P3 and P5	⇧ ⇧	⇧ ⇧
	IGL	P3 and P5	⇧	⇧
	EGL, ML and PCL and WM	P7	⇧ ⇧ ⇧	⇧ ⇧ ⇧
	IGL	P7	⇧	⇧
	IGL WM	P14	⇧ ⇧ ⇧	Not detected
	ML and PCL	P14	Not detected

EGL, external granular layer; IGL, internal granular layer; MK, midkine; ML, molecular layer; PTN, pleiotrophin; PMZ, pre-migratory zone; PLZ, proliferative zone; PCL, Purkinje cell layer; WM, white matter.