Cerebral correlates of visual lateralization in Sepia.
The common cuttlefish, Sepia officinalis (cephalopod mollusc) has recently become a relevant model for studying the setting-up of brain asymmetry among invertebrates. As the animals age from 3 to 30 days post hatching, they progressively develop a left-turning bias resulting from an eye-use preference. The aim of this study is to investigate whether anatomical (vertical, peduncle, inferior buccal, and optic lobes) or neurochemical (monoamines in optic lobes) brain asymmetries are present in the cuttlefish brain at 3 or at 30 post hatching days; and whether these correlate with side-turning preferences. We here find brain and behavioral asymmetry only at 30 post hatching days. Cuttlefish displayed a significant population bias towards a larger right peduncle lobe, and higher monoamine concentration in the left optic lobe (i.e. serotonin, dopamine and noradrenaline). None of these brain asymmetries were correlated to the studied side-turning bias. However, we found individual variation in the magnitude of the vertical and optic lobes asymmetry. A striking correlation was found with the behavioral results: the larger the right optic lobe and the right part of the vertical lobe, the stronger the bias to turn leftwards. To our knowledge, this is the first study to demonstrate a relationship at the individual level between brain and behavioral asymmetries in invertebrates.
Université de Caen Basse-Normandie, Groupe Mémoire et Plasticité comportementale, F-14032 Caen cedex, France. christelle.alves@unicaen.fr
Christelle
C
Jozet-Alves
Sébastien
S
Romagny
Cécile
C
Bellanger
Ludovic
L
Dickel
D000375:Aging; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001921:Brain / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D007839:Functional Laterality / Q000502:physiology*; D009638:Norepinephrine / Q000378:metabolism; D009899:Optic Lobe, Nonmammalian / Q000166:cytology / Q000378:metabolism; D049833:Sepia / Q000033:anatomy & histology* / Q000254:growth & development / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism
D012701:Serotonin; D004298:Dopamine; D009638:Norepinephrine