MicroRNAs are deeply linked to the emergence of the complex octopus brain

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown

Published: Feb. 16, 2022

Abstract Soft-bodied cephalopods such as the octopus are exceptionally intelligent invertebrates with a highly complex nervous system that evolved independently from vertebrates. Because of elevated RNA editing in their tissues, we hypothesized regulation may play major role cognitive success this group. We thus profiled mRNAs and small RNAs 18 tissues common octopus. show innovation soft-bodied is massive expansion miRNA gene repertoire. These novel miRNAs were primarily expressed neuronal during development, had conserved likely functional target sites. The only comparable expansions happened, strikingly, Thus, propose intimately linked to evolution animal brains. One-Sentence Summary deeply emergence

Language: Английский

---

Diffusion MRI Connections in the Octopus Brain

Experimental Neurobiology, Journal Year: 2022, Volume and Issue: 31(1), P. 17 - 28

Published: Feb. 28, 2022

Using high angle resolution diffusion magnetic resonance imaging (HARDI) with fiber tractography analysis we map out a meso-scale connectome of the Octopus bimaculoides brain. The brain this cephalopod has qualitatively different organization than that vertebrates, yet it exhibits complex behavior, an elaborate sensory system and cognitive abilities. Over last 60 years wide ranging detailed studies octopus anatomy have been undertaken, including classical histological sectioning/staining, electron microscopy neuronal tract tracing injected dyes. These elucidated many connections within among anatomical structures. Diffusion MRI based utilizes method offers facile three-dimensional images can be quantitatively analyzed. Twenty-five separate lobes were segmented in 3D MR each three samples, all five sub-structures vertical lobe. parcellations used to assay tracings between lobes. connectivity matrix constructed from data was largely agreement assembled earlier studies. one major difference lobe more basal supra-esophageal structures present literature not found by MRI. In all, 92 25 noted MRI: 53 26 optic other represent beginnings mesoscale

Language: Английский

---

Behavioral Repertoire of lab-reared early juveniles of the Mexican four-eyed octopus:Octopus maya

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: April 17, 2024

ABSTRACT Behavioral studies have predominantly focused on organisms within the phyla Craniata and Arthropoda. Yet, there has been a growing interest in studying behavior of from alternative phyla, such as mollusks, owing to research opportunities they offer. Among cephalopods emerged prominent subject inquiry. However, behavioral Mexico’s endemic species, Octopus maya (Om) , remains conspicuously scarce. Om exhibits favorable attributes for utilization standardized animal model neuroscience research, primarily due its adaptability laboratory settings successful raising multiple generations. A comprehensive understanding ’s environments is essential harness potential model. Thus, main goal this study was establish catalog under conditions. Thirteen subjects (6 20 grams) were housed controlled tank environments. Our findings reveal that diverse repertoire, comprising minimum twenty-one distinct behaviors categorized into six classes. Additionally, displays discernable diurnal nocturnal activity patterns, with increased levels, altered distributions, varying frequencies during daylight hours. This expanded knowledge enhances suitability organism.

Language: Английский

---

Functional organization of visual responses in the octopus optic lobe

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Feb. 16, 2023

Cephalopods are highly visual animals with camera-type eyes, large brains, and a rich repertoire of visually guided behaviors. However, the cephalopod brain evolved independently from that other species, such as vertebrates, therefore neural circuits process sensory information profoundly different. It is largely unknown how their powerful but unique system functions, since there have been no direct measurements responses in brain. In this study, we used two-photon calcium imaging to record evoked primary processing center octopus central brain, optic lobe, determine basic features scene represented organized. We found spatially localized receptive fields for light (ON) dark (OFF) stimuli, which were retinotopically organized across demonstrating hallmark organization shared many species. Examination these revealed transformations representation layers including emergence OFF pathway increased size selectivity. also identified asymmetries spatial ON suggest circuit mechanisms form may suit specific demands an underwater scene. This study provides insight into functional system, highlighting both aspects, lays foundation future studies mediate behavior cephalopods.The response properties unknownUsing imaging, performed mapping lobeVisual demonstrate retinotopic organizationON/OFF pathways selectivity emerge lobe distinct relative

Language: Английский

---

Coleoid Cephalopods Demonstrate Asocial Path to the Evolution of Big Brains

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: May 1, 2024

Abstract Sociality has been argued to be the main selection pressure for evolution of large brains and complex behavior on basis data from mammals birds. Coleoid cephalopods have brains, nervous systems show signs intelligent comparable that birds, cetaceans, primates. However, many live largely solitary, semelparous, short lives, leaving little no opportunity parental care, group dynamics, or social learning. A formal model is needed takes these factors into consideration. Here we test “Asocial Brain Hypothesis” cephalopod molluscs. We compiled a database brain size, ecology, behavior, sociality, life history 3933 publications 79 species octopus, squid, cuttlefish which available. analyze using an updated phylogeny Bayesian multilevel models. In set pre- registered statistical analyses derived predictions model, find effect habitat, suggesting ecology as primary size in cephalopods. also evidence positive relationship between number predator groups sociality. These results are inconsistent with explanations but consistent ecological explanations. They emphasize need new theories explain more generally, including cephalopods, diverged vertebrates over 500 million years ago.

Language: Английский

---