title: Random walk behavior of migrating cortical interneurons in the marginal zone: time-lapse analysis in flat-mount cortex.
abstract: Migrating neurons are thought to travel from their origin near the ventricle to distant territories along stereotypical pathways by detecting environmental cues in the extracellular milieu. Here, we report a novel mode of neuronal migration that challenges this view. We performed long-term, time-lapse imaging of medial ganglionic eminence (MGE)-derived cortical interneurons tangentially migrating in the marginal zone (MZ) in flat-mount cortices. We find that they exhibit a diverse range of behaviors in terms of the rate and direction of migration. Curiously, a predominant population of these neurons repeatedly changes its direction of migration in an unpredictable manner. Trajectories of migration vary from one neuron to another. The migration of individual cells lasts for long periods, sometimes up to 2 d. Theoretical analyses reveal that these behaviors can be modeled by a random walk. Furthermore, MZ cells migrate from the cortical subventricular zone to the cortical plate, transiently accumulating in the MZ. These results suggest that MGE-derived cortical interneurons, once arriving at the MZ, are released from regulation by guidance cues and initiate random walk movement, which potentially contributes to their dispersion throughout the cortex.
authors.affiliation: Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Daisuke H
authors.initials: DH
authors.lastname: Tanaka
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Yanagida
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhu
authors.forename: Sakae
authors.initials: S
authors.lastname: Mikami
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagasawa
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Miyazaki
authors.forename: Yuchio
authors.initials: Y
authors.lastname: Yanagawa
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Obata
authors.forename: Fujio
authors.initials: F
authors.lastname: Murakami
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002465:Cell Movement / Q000235:genetics / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D054377:Chemokine CXCL12 / Q000235:genetics; D055879:Gene Knock-In Techniques; D005968:Glutamate Decarboxylase / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics; D007395:Interneurons / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D011897:Random Allocation; D013997:Time Factors
chemical_list: D054377:Chemokine CXCL12; C515256:Cxcl12 protein, mouse; D049452:Green Fluorescent Proteins; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1