The third alternative: Duplication of collopallium in isocortical evolution
Ann B. Butler a1 a1 Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030
One hypothesis of isocortical evolution requires tangential migration of glutaminergic neurons. A second requires invasion of collothalamic afferents into the dorsal pallium, a territory that in sauropsids is solely lemnopallial. A third alternative is noted here – duplication of the original collopallial territory. The duplicated region would be formed by radial migration of excitatory neurons and would maintain its collothalamic innervation.