Fig. 1.

Structural abnormalities in the postnatal cerebellum. a, b Development of the primary lobes at P0: GAP-43 (+/+) (a) and GAP-43 (−/−) (b). a Primary fissures (f1-4) and the precentral fissure (fprc) in the anterior lobe (AL) are present. The prepyramidal fissure (fppd) in the central lobe (CeL) is beginning to invaginate. b The primary fissures are shorter and invagination of the fprc and fppd are delayed. Asterisks designate the boundaries of the external circumference measured. Scale bar=250 µm. c, d Midsagittal lobes at P21: GAP-43 (+/+) (c) and GAP-43 (−/−) (d). Anterior lobe (AL), I–V; central lobe (CeL), VI–VII; posterior lobe (PL), VIII; nodular lobe (NL), IX–X. The primary fissure (fpr) separates the AL from the CeL. The secondary fissures of the AL are the precentral fissure (fprc) and the preculminate fissure (fpc). The prepyramidal fissure (fppd) separates the CeL from the PL. The secondary fissure of the CeL is the posterior superior fissure (fps). The secondary fissure (fsec) separates the PL from the NL. The secondary fissure of the NL is the posterolateral fissure (fpl). c Arrow indicates the fiber branch absent or attenuated in GAP-43 (−/−) mice. d Arrows indicate significantly altered fissures and sulci. Scale bar=100 µm. e, f Surface appearance of 7-month-old cerebella revealed with India ink: GAP-43 (+/+) (e) and GAP-43 (−/−) (f). Roman numerals V–IX indicate folia at the vermis. Lobes at the hemispheres are: S simplex, CI crus I, CII crus II, P paramedial, F paraflocculus. Visible fissures at the vermis: primary fissure (fpr); posterior superior fissure (fps); prepyramidal fissure (fppd); secondary fissure (fsec); intraculminate fissure (ficul). Superior colliculus (SC) and inferior colliculus (IC). Arrows indicate where the lateral lobes intersect with the vermis. Scale bar=1 mm (n=18 mice examined from each genotype)