Biology subjects

Vergara-Ovalle, F.

Publications and source records attributed to Vergara-Ovalle, F..

3 recordsLinked to original sources

bioRxiv2025

Habituation-Induced Expression of Immediate Early Genes in the Octopus Brain

Understanding the neural basis of learning and memory in cephalopods remains challenging because of their behavioral complexity and the limited reproducibility of memory tasks. Here, I present a combined behavioral and molecular analysis using a simple habituation paradigm, Training Response to Artificial Prey (TRAP), in Octopus bimaculoides. Subjects showed a rapid, stimulus-specific decrease in exploration of a neutral prey-like object across trials. Habituation occurred in 100% of two- and six-month-old subjects, and multiple daily trials induced long-term memory lasting up to five days. Using whole-mount Hybridization Chain Reaction (HCR), I detected spatial activation of candidate immediate early genes, creb and egr1, during early memory consolidation. 15 minutes after learning, both genes were upregulated across the central brain, mainly in the subesophageal lobes, and axial ganglia. At 30 minutes, expression spread to the supraesophageal region, notably the vertical lobe, consistent with regions implicated in long-term memory. These results demonstrate a sequential activation from arms to subesophageal and supraesophageal regions, supporting proposed models of distributed information processing in the octopus nervous system. HIGHLIGHTSO_LITraining Response to Artificial Prey (TRAP) is a simple and highly repeatable method to evaluate memory in octopuses. C_LIO_LIRepeated trials induced robust, long-term habituation lasting up to five days. C_LIO_LIImmediate early genes creb and egr1 were rapidly upregulated after training. C_LIO_LI(d) Gene expression spread sequentially across nervous system regions recruited for memory formation. C_LI

animal behavior and cognition↗

bioRxiv2024

Behavioral Repertoire of lab-reared early juveniles of theMexican four-eyed octopus, Octopus maya.

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

animal behavior and cognition↗

bioRxiv2022

Specific Ethogram of the Mexican four-eyed octopus: Octopus maya.

Historically, behavior studies have focused mainly on animals of two phyla in particular: Craniata and Arthropoda, however, behavioral research on alternative phyla like mollusks has been increasing because of the potential for research that these models present. When we talk about mollusk behavior, cephalopods are the first group that stands out, however, research on Mexicos endemic species like Octopus maya, is still lacking. This octopus could help to reach a standardized model in neuroscience, because adapts well to laboratory conditions and has been successfully cultured through several generations. These characteristics provide a great advantage as a research model since they could reduce the number of variables that affect behavioral studies, something hard to control with a captured-wild octopus. Hence, in order to work properly with species like this, in research environments, its fundamental to know first the behaviors that this species can perform there. Therefore, the objective of this study was to elaborate an ethogram that describes the behavioral repertoire that O. maya displays in laboratory conditions. Thirteen individuals of O. maya (6-20g) were used and maintained in tanks with a closed circulation seawater system and illuminated with a red light of 30 lx in a 12:12 LD cycle. Nine of these individuals were used for an ad libitum sampling of behaviors to name, define, categorize and operationally describe them. The last four individuals were used to establish day/night activity patterns, (length and frequency of behaviors throughout the day). The obtained results showed that O. maya has a wide behavioral repertoire with at least twenty-three behaviors, which were included in six different behavioral categories. The obtained results showed that O. maya has a wide behavioral repertoire with at least twenty-three behaviors, which were organized in six different behavioral categories. Also, this species showed differentiated activity patterns between day and night, with peaks of activity, distribution, and frequencies of activity behaviors mainly during the light hours. These results showed that O. maya has behaviors comparable with other octopus species and support the proposal for its use as a viable research model. Knowing the behavioral repertoire of O. maya allows for better control in future behavioral studies using this model, provides the main tools to evaluate the organisms health and status, and supports its use for research in neuroscience and cognition.

animal behavior and cognition↗