A cell line has been established in continuous culture of human cerebral cortical neurons obtained from a patient with unilateral megalencephaly, a disorder associated with continued proliferation of immature neuronal cells. When differentiated in the presence of nerve growth factor, 1-isobutyl-3-methylxanthine, and dibutyryl adenosine 3',5'-monophosphate (cAMP), the cells display mature neuronal morphology with numerous long, extensively branched processes with spines and varicosities. The cells stain positively for neurofilament protein and neuron-specific enolase (selective neuronal markers) but are negative for glial markers, such as glial fibrillary acidic protein, S-100, and myelin basic protein. The cells also stain positively for the neurotransmitters gamma-aminobutyric acid (GABA), glutamate, somatostatin, cholecystokinin-8, and vasoactive intestinal polypeptide. These cells may facilitate characterization of neurons in the human central nervous system.

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The Flin Flon -Kisseynew boundary in the eastern Trans-Hudson Orogen is interpreted here as an early thrust fault that places 1.86 -1.84 Ga Kisseynew belt turbidites over previously deformed 1.91 -1.88 Ga arc and ocean-floor assemblages of the Flin Flon belt. The basin in which sedimentary rocks of the Kisseynew belt were deposited has been interpreted to have formed partly within the Flin Flon belt. The fault that juxtaposes the two belts is interpreted to have been localized near the ancestral basin margin, resulting in development of a major ramp zone during basin closure. This interpreted ramp zone provides an explanation for the steep to shallow structural transition that corresponds to increasing metamorphic grade. Collapse of the Kisseynew sedimentary basin and juxtaposition of the two belts are attributed to southwest-verging folding and thrusting that initiated prior to emplacement of 1.83 Ga plutons. This magmatism was followed by regional greenschist-to upper-amphibolite-grade metamorphism (1.82-1.805 Ga) and renewed southwest-directed folding and thrusting. Late backfolds developed at the leading edge of the fold-thrust belt. Postpeak metamorphic deformation resulted in large-scale, upright folding of the fold-thrust stack (including the Flin Flon -Kisseynew boundary). This stage of deformation is interpreted to record a transition from southwest-directed transport to northwest -southeast-directed shortening at -1.8 Ga.Resume : La limite de Flin Fon -Kisseynew dans la r6gion orientale de I'Orogttne trans-hudsonien est consid6rCe ici comme une faille de chevauchement prkcoce, qui a transport6 les turbidites de la zone de Kisseynew, lg6es de 1,86-1,84 Ga, sur les assemblages de la zone de Flin Flon form& de roches d'arc et de plancher ocCanique, datCes de 1,91-1,88 Ga. Le bassin dans lequel les roches skdimentaires de la zone de Kisseynew furent dCpos6es a Ct C interpret6 cornrne ayant 6t6 form6 partiellement 21 I'intCrieur de zone de Flin Flon. On croit que la faille juxtaposant les deux zones fut localis6e prtts de la marge du bassin ancestral, et qu'elle fut responsable du d6veloppement d'une importante zone de rampe durant le stade de fermeture du bassin. Cette zone de rampe inf6rCe permet d'expliquer la transition structurale de grande profondeur B faible profondeur associCe au degr6 croissant de m6tamorphisme. L'affaissement du bassin saimentaire de Kisseynew et la juxtaposition des deux zones sont des Cvttnements attribuCs aux plissements de vergence sud-ouest et au chevauchement, qui sont survenus antkrieurement B la mise en place des plutons lgCs de 1,83 Ga.Ce magmatisme fut suivi d'une alt6ration mktamorphique regionale de faciks des schistes verts ?I fac3s sup6rieur des amphibolites (1,82-1,805 Ga), et du replissement des plis en direction sud-ouest et aussi de la rkactivation de la faille de chevauchement. Des plis en retour tardifs se sont d6veloppCs sur le bord avant de la zone de chevauchement et plissements. Une deformation postkrieure au stade de mCtamorphisme paroxysmal a eu pour rCsul...