Fig. 11.

Early steps in the development of the projections between thalamus (TH) and cortex (CX) and their relationships with the early efferent projections from the basal telencephalon. 1, Cortical axons from preplate cells (gray) begin to enter the LGE, and axons from dorsal thalamic cells (black) begin to enter the MGE. Reciprocally, cells in the LGE (open circle) send a projection to the cortex, and cells in the MGE (open circle) send a projection to the dorsal thalamus. 2, Thalamic and cortical fibers distribute within the GE, but do not enter the cortical wall or the dorsal diencephalon, respectively. The projections between the LGE and the embryonic neocortex show a rostrocaudal differentiation.3, Thalamic and cortical fibers have reached their target region. The efferent projections from the GE to the cortex and the thalamus become reshaped or reduced.