Table 1.

Cortical tissue samples.

Postnatal Age (Days)	Visual	Somatosensory	Frontal
0		x	x
4	x	x	x
7		x
11	x	x	x
14	x	x	x
17	x	x	x
21	x	x	x
25	x	x	x
28	x	x	x
31	x	x	x
35	x	x	x
45	x	x	x
64	x		x
74	x	x	x
93	x		x