Calretinin distribution in the octopus brain: An immunohistochemical and in situ hybridization histochemical analysis

• Published in: Brain research 2007-02, Vol.1132 (1), p.71-77
• Main Authors: Altobelli, Giovanna G, Cimini, Vincenzo
• Format: Article
• Language: English
• Subjects: Amacrine Cells - cytology; Amacrine Cells - metabolism; Anatomy; Animals; Biological and medical sciences; Brain; Brain - anatomy & histology; Brain - metabolism; Brain Mapping; Calbindin 2; Calcium - metabolism; Calcium-binding protein; Calretinin; Central nervous system; Cephalopod; Cortex; Endocrine System - cytology; Endocrine System - metabolism; Evolution; Evolution, Molecular; Fundamental and applied biological sciences. Psychology; Ganglia, Invertebrate - anatomy & histology; Ganglia, Invertebrate - metabolism; Immunocytochemistry; Immunohistochemistry; In Situ Hybridization; Neurology; Neurons - metabolism; Neuropil; Octopodiformes - anatomy & histology; Octopodiformes - metabolism; Octopus; Phylogeny; RNA, Messenger - metabolism; S100 Calcium Binding Protein G - genetics; S100 Calcium Binding Protein G - metabolism; Vertebrates: nervous system and sense organs; Western blot
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2006.11.056

Abstract The distribution of calretinin containing neurons examined by in situ hybridization mapping was compared with that obtained by immunocytochemistry in the brain of octopus. Results revealed a close correspondence between the two types of investigations. Western blot analysis disclosed a 29 kDa protein immunostained with anti-calretinin antibody. Calretinin containing neurons were localized mainly in the cortex of octopus lobes, including the vertical, frontal, basal, buccal, palliovisceral, pedal and branchial, with variations of staining intensity and density of immunoreactive cells. The amacrine cells surrounding calretinin containing neuronal bodies of the cortex were also labeled unlike the glial cells. The close correspondence of blotting analysis, immunocytochemistry and in situ hybridization indicates with no doubt that calretinin, like other calcium-binding proteins previously studied, is also present in the nervous system of cephalopods. Furthermore, although recent findings localize calretinin also in endocrine glands, the presence of this calcium-binding protein in the brain of octopus indicates that calretinin appeared early in the phylogeny as a neuronal protein already in invertebrates.