Skip to main content
Fig. 5 | Zoological Letters

Fig. 5

From: Evidence for a cordal, not ganglionic, pattern of cephalopod brain neurogenesis

Fig. 5

ELAV gene expression in O. bimaculoides embryos demonstrates the cordal development of octopus brain. a–j Wholemount ELAV in situ hybridization on early (a–d, i and j), middle (e and f) and late (g) stage embryos and hatchling brain (h). Orientation is an end on view as in Fig. 2b and c, with anterior to the top of the panel. b, i, and j High power images of cerebral cord (b, i) and palliovisceral cord (j) territories shown in a and c respectively. k Cross section taken through middle stage embryo wholemount, oriented with the mantle at the top as in Fig. 2g and h. Arrowhead in B shows ELAV-rich cells populating the midline at the earliest stage of detection. Arrows in C denote the lateral extent of the midline territories of early-born neurons in the cerebral cord (top, arrows with long stems) and the pedal cord (bottom, arrows with short stems). White arrowheads in C identify the limits of ELAV-positive cells extending from the concentrations of palliovisceral neurons inside the collar folds. White arrowheads in D point to the anterior limits of the palliovisceral cord. In df, the level of expression in the pedal cord is not faithfully documented because the pedal cord at these stages is in part shifted deep to the palliovisceral cord. The ELAV territories within the mantle identify the developing peripheral nervous system, including the prospective stellate ganglia (stg) illustrated in k. The limits of the mantle (m), statocysts (st) and olfactory organs (olf) are marked with dots. In eh, the mantle has been cut away (solid circle, revealing the inner yolk, iy) so that the view of the brain primordia is unobstructed. 1-4, arms 1-4; cc, cerebral cord; co, collar; ey, eye; mo, mouth; opt, optic lobes; pedc, pedal cord; pvc, palliovisceral cord; subes, subesophageal mass; supes, supraesophageal mass. Scale bars: 500 μm (ah, k), 250 μm (i, j)

Back to article page