Table 1. An historical overview of phenomena described to occur after lesion of the pallial nerve in Octopus vulgaris.

Structure and/or Events		Young, 192919	Sereni & Young, 193217	Young, 197220	Sanders &Young, 197414	This study
Nerve Fibers	Degeneration	√	√	√	√	√
	Regeneration		√	√	√	√
Scar formation			√			√
Hemocytes	Infiltration among nerve fibers		√			√
	Proliferation		√			√
	Phagocytosis		√
	Contribution to scar		√			√
Connective tissue cells	Proliferation					√
	Neuronal marker expression					√
Neuronal Cells	Presence in the nerve					√
	Proliferation					√
First signs of functional recovery of body patterning					30d	7d

The information obtained in this study is summarized here as comparison. Young¹⁹ observed only degeneration of both stumps within the first 10 days after lesion (d), no further degenerative phenomena were reported till the end of the experiments (40 days in Young¹⁹). Sereni and Young¹⁷ observed “amoebocytes” infiltration into the cut stumps, especially the peripheral one, where they appear to phagocytose actively. Young²⁰ reported a “vigorous” regeneration originating from the peripheral stump of the pallial nerve, and suggested this due to the afferent fibers from the periphery.

Some of the most significant events occurring after lesion of the octopus pallial nerve are described for the first time in this study.