Through the Looking-Glass of Cephalopod Colour Patterns

Packard, Andrew

doi:10.1007/978-94-011-0091-5_5

Cited by 10 publications

(14 citation statements)

References 26 publications

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“…Indeed, using the four main papillae of the mantle as landmarks, we observed shrinkage of the area affected by these phenomena (i.e. wandering clouds, yellowing and mechanical excitability) a few days (around 5-7 days) post-lesion, as also described by Packard (1995), which continued to reduce with time. In particular, the skin along the midline, the mantle tip and close to the head on the injured side returned to its original appearance (see Fig.…”

Section: Wandering Clouds On the Denervated Skinsupporting

confidence: 65%

“…These were recorded daily when the animal was at rest (at least 10 min before) and after the presentation of the live prey in the octopus' tank to assess its readiness to attack. Through analysis of the video recordings, two independent observers scored the body pattering and the approximate areas of blanching of the skin (mantle and any other body part) according to descriptions provided elsewhere (Packard, 1991(Packard, , 1995Sanders and Young, 1974). Body patterning observed during the analysis of video recordings was also coded following Borrelli et al (2006).…”

Section: Behavioural Responsesmentioning

confidence: 99%

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From injury to full repair: nerve regeneration and functional recovery in the common octopus, Octopus vulgaris

Imperadore

Parazzoli

Oldani

et al. 2019

Journal of Experimental Biology

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Spontaneous nerve regeneration in cephalopod molluscs occurs in a relative short time after injury, achieving functional recovery of lost capacity. In particular, transection of the pallial nerve in the common octopus (Octopus vulgaris) determines the loss and subsequent restoration of two functions fundamental for survival, i.e. breathing and skin patterning, the latter involved in communication between animals and concealment. The phenomena occurring after lesion have been investigated in a series of previous studies, but a complete analysis of the changes taking place at the level of the axons and the effects on the animals' appearance during the whole regenerative process is still missing. Our goal was to determine the course of events following injury, from impairment to full recovery. Through imaging of the traced damaged nerves, we were able to characterize the pathways followed by fibres during regeneration and end-target re-innervation, while electrophysiology and behavioural observations highlighted the regaining of functional connections between the central brain and periphery, using the contralateral nerve in the same animal as an internal control. The final architecture of a fully regenerated pallial nerve does not exactly mirror the original structure; however, functionality returns to match the phenotype of an intact octopus with no observable impact on the behaviour of the animal. Our findings provide new important scenarios for the study of regeneration in cephalopods and highlight the octopus pallial nerve as a valuable 'model' among invertebrates.

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Section: Wandering Clouds On the Denervated Skinsupporting

confidence: 65%

Section: Behavioural Responsesmentioning

confidence: 99%

From injury to full repair: nerve regeneration and functional recovery in the common octopus, Octopus vulgaris

Imperadore

Parazzoli

Oldani

et al. 2019

Journal of Experimental Biology

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“…Chromatophores can exhibit not only full expansion but also intermediate expansion in which the muscles produce graded contractions. These variations in the state of expansion (rather than intensity of pigment) of dark chromatophores are responsible for variations in contrast of the chromatic patterns produced [9], [10], [11], [12]. In intact cuttlefish, recordings of the electrical activity from motor nerves innervating chromatophores in black spot areas of a deimatic chromatic pattern showed an increased firing rate when the pattern was displayed [13].…”

Section: Introductionmentioning

confidence: 99%

Chromatophore Activity during Natural Pattern Expression by the Squid Sepioteuthis lessoniana: Contributions of Miniature Oscillation

et al. 2011

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Squid can rapidly change the chromatic patterns on their body. The patterns are created by the expansion and retraction of chromatophores. The chromatophore consists of a central pigment-containing cell surrounded by radial muscles that are controlled by motor neurons located in the central nervous system (CNS). In this study we used semi-intact squid (Sepioteuthis lessoniana) displaying centrally controlled natural patterns to analyze spatial and temporal activities of chromatophores located on the dorsal mantle skin. We found that chromatophores oscillated with miniature expansions/retractions at various frequencies, even when the chromatic patterns appear macroscopically stable. The frequencies of this miniature oscillation differed between “feature” and “background” areas of chromatic patterns. Higher frequencies occurred in feature areas, whereas lower frequencies were detected in background areas. We also observed synchronization of the oscillation during chromatic pattern expression. The expansion size of chromatophores oscillating at high frequency correlated with the number of synchronized chromatophores but not the oscillation frequency. Miniature oscillations were not observed in denervated chromatophores. These results suggest that miniature oscillations of chromatophores are driven by motor neuronal activities in the CNS and that frequency and synchrony of this oscillation determine the chromatic pattern and the expansion size, respectively.

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“…We cannot exclude that alternative mechanisms might also be involved and aid to chromatophore re-innervation, such as intervention through collateral nerve sprouting of the stellar nerves from the opposite stellate ganglion (as suggested by Packard, 1995). This is further supported by the fact that the mantle midline and the areas close to it return functional much earlier than other areas (see Supplementary Material, Fig.…”

Section: Discussionmentioning

confidence: 99%

“…each animal has a pair of nerves, one on each side of the mantle, allowing the same animal to serve as experimental and control; iv. the same nerve can be lesioned several times providing almost complete regeneration at each instance (Packard, 1995); v. the majority of the cell soma of axons in the pallial nerve resides inside the brain, but others in the ganglia at periphery. Both can regenerate, allowing a comparison of regeneration ability of the two ‘systems’, one being spatially more centrally the other more peripherally located; vi.…”

Section: Discussionmentioning

confidence: 99%

From injury to full repair: nerve regeneration and functional recovery in the common octopus,Octopus vulgaris

Imperadore

Parazzoli

Oldani

et al. 2019

Preprint

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Spontaneous nerve regeneration in cephalopod molluscs occurs in a relative short time after injury, achieving functional recovery of the lost capacities. In particular, transection of the pallial nerve in the common octopus (Octopus vulgaris) determines loss and subsequent restoring of two functions fundamental for survival, i.e. breathing and skin patterning, the latter involved in communication between animals and concealing. The phenomena occurring after lesion have been investigated in a series of previous studies, but a complete analysis of the changes occurring at the level of the axons and the effects on animals appearance during the whole regenerative process is still missing. Our goal is to determine the course of events following injury. Our goal is to determine the course of events following injury, from impairment to full recovery.We observed nerve regeneration, end-target re-innervation and functional reconnections between central brain and periphery, using the contralateral nerve in the same animal as internal control. The final architecture of the regenerated nervous tissue does not mirror the original structure, however functionality returns to match the phenotype of an intact octopus, and with no visible impact on the behaviour of the animal. This provides exceptional value to these findings for future studies.Summary statementHere we report events occurring after interruption of the peripheral neural circuitry in Octopus vulgaris, from the dramatic loss of normal functioning to full recovery.

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Through the Looking-Glass of Cephalopod Colour Patterns

Cited by 10 publications

References 26 publications

From injury to full repair: nerve regeneration and functional recovery in the common octopus, Octopus vulgaris

From injury to full repair: nerve regeneration and functional recovery in the common octopus, Octopus vulgaris

Chromatophore Activity during Natural Pattern Expression by the Squid Sepioteuthis lessoniana: Contributions of Miniature Oscillation

From injury to full repair: nerve regeneration and functional recovery in the common octopus,Octopus vulgaris

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