Histamine and histidine decarboxylase in the olfactory system and brain of the common cuttlefish Sepia officinalis (Linnaeus, 1758)

Abstract

Cephalopods are radically different from any other invertebrate. Their molluscan heritage, innovative nervous system, and specialized behaviors create a unique blend of characteristics that are sometimes reminiscent of vertebrate features. For example, despite differences in the organization and development of their nervous systems, both vertebrates and cephalopods use many of the same neurotransmitters. One neurotransmitter, histamine (HA), has been well studied in both vertebrates and invertebrates, including molluscs. While HA was previously suggested to be present in the cephalopod central nervous system (CNS), Scaros, Croll, and Baratte only recently described the localization of HA in the olfactory system of the cuttlefish Sepia officinalis. Here, we describe the location of HA using an anti‐HA antibody and a probe for histidine decarboxylase (HDC), a synthetic enzyme for HA. We extended previous descriptions of HA in the olfactory organ, nerve, and lobe, and describe HDC staining in the same regions. We found HDC‐positive cell populations throughout the CNS, including the optic gland and the peduncle, optic, dorso‐lateral, basal, subvertical, frontal, magnocellular, and buccal lobes. The distribution of HA in the olfactory system of S. officinalis is similar to the presence of HA in the chemosensory organs of gastropods but is different than the sensory systems in vertebrates or arthropods. However, HA's widespread abundance throughout the rest of the CNS of Sepia is a similarity shared with gastropods, vertebrates, and arthropods. Its widespread use with differing functions across Animalia provokes questions regarding the evolutionary history and adaptability of HA as a transmitter.

A Perspective on Cephalopods Mimicry and Bioinspired Technologies toward Proprioceptive Autonomous Soft Robots

“…Cephalopods’ sensorimotor system is neural refined and hierarchically organized so that they can change their total body appearance (both coloration and texture) in hundreds milliseconds. [ 304 ] In the brain, the optic lobes, the lateral basal lobes, and the anterior/posterior chromatophore lobes steer the skin patterns (by means of the neural control of the chromatophores, iridophores, leucophores and papillae). [ 305 ] While the central nervous system controls the neural cells connected to chromatophores, the peripheral nervous system dynamically drives the papillae responsible for skin texture and the iridescent organs ( Figure a‐i).…”

Proteomic analysis of the spineless cuttlefish Sepiella japonica: Exploratory analyses on the phenomenon of death after spawning

“…Indeed, it is not well clear whether these signalling pathways play any pivotal roles in S. japonica. Therefore, the application of label-free proteomic analysis of S. japonica would certainly add more insights into the understanding of its physiological processes, including death after spawning (Scaros et al, 2020).…”

Exploration of chemosensory ionotropic receptors in cephalopods: the IR25 gene is expressed in the olfactory organs, suckers, and fins of Sepia officinalis

“…But we still have little information on how the diversity of odorant cues is perceived and integrated (Mobley et al 2007). Behind the diversity of cell types, a large diversity of neurotransmitters A c c e p t e d M a n u s c r i p t 4 has been described (Scaros et al 2018, Scaros et al 2020) and in the central nervous system, there is nothing resembling the vertebrate glomeruli that could potentialize odor discrimination (Scaros et al 2018). Finally, chemoreceptors for olfaction are still undescribed in cephalopods.…”