Biology subjects

Almansa, E.

Publications and source records attributed to Almansa, E..

5 recordsLinked to original sources

bioRxiv2026

Protocol for calcium imaging of acute brain slices from Octopus vulgaris hatchlings during application of neurotransmitters

Octopus vulgaris and other cephalopods are of increasing interest as neurobiological model organisms. This protocol describes a method to record calcium activity from individual cells in acute brain slices from Octopus vulgaris hatchlings during exogenous application of neurotransmitters. Using this protocol, we characterized single-cell responses to specific neurotransmitters in the optic lobes, which process visual information. The approach is readily adaptable to other cephalopods and small invertebrate species. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=146 HEIGHT=200 SRC="FIGDIR/small/711860v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1a3da0forg.highwire.dtl.DTLVardef@412424org.highwire.dtl.DTLVardef@abda7eorg.highwire.dtl.DTLVardef@958ebf_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2025

Isolation and primary culture of Octopus vulgaris cells: Assessment of their proliferative capacity

The octopus cell culture system represents a useful tool in various fields, such as biological studies and sustainable octopus production. In this paper, we describe the isolation procedure and culture protocols, metabolic activity, and the proliferative capacity assessment of the common octopus (Octopus vulgaris) cells, at three different life stages: embryo, paralarvae and adult. Isolation of cells was carried out with minimum essential medium (MEM) or Leibovitz L-15 medium, using 0.4 % type I collagenase for 2 (paralarvae and embryo) or 3 h (adult) at 25 {degrees}C. Isolated cells showed significant metabolic activity, demonstrating their viability for in vitro studies. The culture of isolated cells in MEM or L-15 supplemented with different sera (4 % fetal bovine serum (FBS), 10 % FBS and 5 % haemolymph (HEMO)) was viable for 168 h, although the survival of different cell types was variable. A detachment protocol using trypsin was also successfully developed. Finally, isolated muscle cells from both paralarval and adult specimens were marked with the mitotic indicator PHH3. Results from flow cytometry analysis showed that all developmental stages examined contained cells in mitotic phase, with embryos XII-XIII showing the highest proportion. This study provides novel guidelines for the in vitro culture of O. vulgaris cells, which are useful for the future development of cellular aquaculture, understood as the production of lab-grown meat for this species. Moreover, the results reported in this communication could contribute to reduce the use of animals for scientific purposes as well as providing a new option for human consumption of cephalopods.

cell biology↗

bioRxiv2025

Novel dopaminergic neurotransmission in the Octopus visual system

Octopus vulgaris, the common octopus, has a complex brain that evolved independently from that of vertebrates, raising the possibility that it may be built using novel circuit motifs or non-canonical neurochemistry. Through systematic characterization of octopus ligand-gated ion channel genes, we identified novel ionotropic receptors for two neurotransmitters, dopamine and acetylcholine, that play key roles in visual circuits. One of these, DopC1, encodes a dopamine-gated cation channel expressed in deeper layers of the optic lobe (inner granular layer and medulla). A second, AChRB1, encodes an acetylcholine-gated anion channel expressed in photoreceptors and dopaminergic outer granular layer neurons. Dopamine drives excitation, particularly in deeper, DopC1 enriched layers, and thereby may play an important role in feed-forward excitation, whereas acetylcholine evokes inhibition, possibly mediating negative feedback from deeper layers. The octopus visual system thus shows fundamental differences in both neurochemistry and wiring compared to mammals, implying distinct mechanisms of visual information processing.

neuroscience↗

bioRxiv2025

Ultrasound-based prediction of spawning time in females of Octopus vulgaris

There has been a great interest in common octopus Octopus vulgaris aquaculture over recent years and commercial production is coming within reach. In addition, O. vulgaris is a short-lived semelparous species with a long spawning period. Therefore, monitoring ovary maturation in cultured octopuses can be useful in the scheduling of hatchery operations and management of culture resources. The present work aimed to assess the ovary maturity status in cultured and wild common octopus by means of a noninvasive technique, ultrasonography, to anticipate the time of spawning in aquaculture. A total of 27 octopuses (15 cultured and 12 wild ones) in different ovarian maturation stages were used in ultrasonographic procedures. Ultrasound-based ovary volumes were compared with real ovarian volumes and then the ultrasonography-based gonadosomatic index (GSIU) was estimated. Data from cultured females indicate that GSIU was initially below 0.3 cm3 per 100 g of body weight in immature animals, and attained a fast increase until reaching about 4.0 cm3 per 100 g of body weight right before spawning. The steep increase in relative volume occurred similarly in females of different body weights. In addition, the specific growth rate of cultured animals decreases with time, and with GSIU. Lastly, a linear mixed model indicated a significantly negative and logarithmic relationship between the time to spawning and GSIU in captive females. That relationship will be useful to predict spawning time in immature and maturing females, helping in the management of octopus broodstocks in research and production facilities.

zoology↗

bioRxiv2020

A practical staging atlas to study embryonic development of Octopus vulgaris under controlled laboratory conditions

BackgroundOctopus vulgaris has been an iconic cephalopod species for neurobiology research as well as for cephalopod aquaculture. It is one of the most intelligent and well-studied invertebrates, possessing both long- and short-term memory and the striking ability to perform complex cognitive tasks. Nevertheless, how the common octopus developed these uncommon features remains enigmatic. O. vulgaris females spawn thousands of small eggs and remain with their clutch during their entire development, cleaning, venting and protecting the eggs. In fact, eggs incubated without females usually do not develop normally, mainly due to biological contamination (fungi, bacteria, etc.). This high level of parental care might have hampered laboratory research on the embryonic development of this intriguing cephalopod. ResultsHere, we present a completely parameter-controlled artificial seawater standalone egg incubation system that replaces maternal care and allows successful embryonic development of a small-egged octopus species until hatching in a laboratory environment. We also provide a practical and detailed 1 staging atlas based on bright-field and light sheet fluorescence microscopy imaging for precise monitoring of embryonic development. The atlas has a comparative section to benchmark stages to the different scales published by Naef (1928), Arnold (1965) and Boletzky (2016). Finally, we provide methods to monitor health and wellbeing of embryos during organogenesis. ConclusionBesides introducing the study of O. vulgaris embryonic development to a wider community, this work can be a high-quality reference for comparative evolutionary developmental biology.

developmental biology↗