Figure 6.

Photomicrographs of intracallosal NK1_{IP ‐n} at three postnatal ages (P5‐P7‐P10). a–e: P5; f: P7; g–j: P10. a–d: Four intracallosal NK1_{IP ‐n} showing different morphologies. (a) An ovoid NK1_{IP ‐n} with a thick principal dendrite directed toward the ependymal cc region. (b and d) Two round NK1_{IP ‐n} close to the ependymal cc region, whose dendrites are directed toward the dorsal, posterior and anterior cc regions. (c) Two adjacent NK1_{IP ‐n} in the middle of the cc. (e) Medial cc region, probably between lateral at 0.9 and 0.4 mm (comparable with those of the adult): no neurons are found at this cc level. Several NK1_{IP ‐n} are visible over the cc, in the IG. (f) An ovoid NK1_{IP ‐n} with dendrites directed in all directions, including the ependymal cc region. Arrowhead: a growth bud. (g) Polygonal NK1_{IP ‐n}. (i) Several intracallosal NK1_{IP ‐n}. A neuron (asterisk) sends its dendrites into the CPu. (j) A bipolar NK1_{IP ‐n} close to the ependymal region of the cc. Arrowheads in d and f indicate growth buds at branching points. Calibration bars: 25 μm in a–d, f, g, i, j; 100 μm in e; 10 μm in h