Thigmotaxis (from Greek thigma, "touch" meaning contact with an object, and taxis , "arrangement, order", meaning reaction by movement [1] ) is a behavioral response to tactile stimuli, typically referring to an organism's movement in response to physical contact with surfaces or objects. For example, animals, when placed into a new enclosed space, tend to stay near the perimeter while avoiding the interior area. This is known as wall-following/touching or centrophobic behavior. [1]
This type of movement is genetically grounded and can be observed in both animals and humans. [1]
This occurs when an organism moves towards or remains in contact with a surface or object. Positive thigmotaxis is often observed in animals seeking shelter or protection, as staying close to surfaces can reduce exposure to predators and environmental hazards.
This occurs when an organism moves away from contact with surfaces or objects. Negative thigmotaxis can be seen in animals that need to navigate open spaces or avoid areas where tactile stimuli indicate danger or discomfort
Laboratory studies of rodents, such as mice and rats, frequently demonstrate positive thigmotaxis. Rodents often prefer to stay close to the walls of an open field or maze, a behavior known as wall-following or thigmotactic behavior. This tendency is utilized in behavioral experiments, such as the open field test, to assess anxiety-like behaviors. [2]
Many insects exhibit thigmotactic behavior. For instance, cockroaches and ants show positive thigmotaxis by staying close to surfaces while foraging or seeking shelter. This behavior helps them navigate complex environments and avoid predation. Similarly to rodents, it is utilized in behavioral experiments, such as the open field test, to assess anxiety-like behaviors. [3]
Certain fish species exhibit thigmotaxis when they seek out and remain close to structures or objects within their aquatic environment. This behavior can provide protection from predators and strong currents.
The mechanisms underlying thigmotaxis involve sensory receptors that detect tactile stimuli. These receptors can be located on various body parts, such as antennae, legs, or skin. When stimulated, these receptors send signals to the nervous system, triggering a motor response that directs the organism's movement.
In vertebrates, the mechanoreceptors in the skin, known as tactile or touch receptors, play a significant role in thigmotactic behavior. In invertebrates, specialized sensory organs such as setae (bristle-like structures) or antennae are involved in detecting and responding to tactile stimuli.
Positive thigmotaxis helps animals find and stay in safe, sheltered areas, which can protect them from predators and harsh environmental conditions.
Thigmotactic behavior aids in navigation through complex environments, allowing animals to efficiently find resources and avoid obstacles.
In some species, thigmotaxis plays a role in social behaviors, such as group cohesion and territory establishment.
In some species, thigmotaxis plays a role in mating behaviors. It is currently debated whether mating status impacts thigmotaxis in Drosophila. [4] [5]
Thigmotaxis is studied extensively in various fields, including neurobiology, and psychology. Understanding thigmotactic behavior can provide insights into the neural mechanisms of sensory processing and motor control. Additionally, researchers use thigmotaxis as a behavioral assay to investigate anxiety, stress, and other psychological states in animal models.[ citation needed ]
Drosophila is a genus of fly, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit. They should not be confused with the Tephritidae, a related family, which are also called fruit flies ; tephritids feed primarily on unripe or ripe fruit, with many species being regarded as destructive agricultural pests, especially the Mediterranean fruit fly.
Drosophila melanogaster is a species of fly in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly", or "banana fly". In the wild, D. melanogaster are attracted to rotting fruit and fermenting beverages, and are often found in orchards, kitchens and pubs.
A taxis is the movement of an organism in response to a stimulus such as light or the presence of food. Taxes are innate behavioural responses. A taxis differs from a tropism in that in the case of taxis, the organism has motility and demonstrates guided movement towards or away from the stimulus source. It is sometimes distinguished from a kinesis, a non-directional change in activity in response to a stimulus.
Stimulus modality, also called sensory modality, is one aspect of a stimulus or what is perceived after a stimulus. For example, the temperature modality is registered after heat or cold stimulate a receptor. Some sensory modalities include: light, sound, temperature, taste, pressure, and smell. The type and location of the sensory receptor activated by the stimulus plays the primary role in coding the sensation. All sensory modalities work together to heighten stimuli sensation when necessary.
A mechanoreceptor, also called mechanoceptor, is a sensory receptor that responds to mechanical pressure or distortion. Mechanoreceptors are innervated by sensory neurons that convert mechanical pressure into electrical signals that, in animals, are sent to the central nervous system.
Neuroethology is the evolutionary and comparative approach to the study of animal behavior and its underlying mechanistic control by the nervous system. It is an interdisciplinary science that combines both neuroscience and ethology. A central theme of neuroethology, which differentiates it from other branches of neuroscience, is its focus on behaviors that have been favored by natural selection rather than on behaviors that are specific to a particular disease state or laboratory experiment.
The star-nosed mole is a small semiaquatic mole found in moist, low elevation areas in the northern parts of North America. It is the only extant member of the tribe Condylurini and genus Condylura, and it has more than 25,000 minute sensory receptors in touch organs, known as Eimer's organs, with which this hamster-sized mole feels its way around. With the help of its Eimer's organs, it may be perfectly poised to detect seismic wave vibrations.
Escape response, escape reaction, or escape behavior is a mechanism by which animals avoid potential predation. It consists of a rapid sequence of movements, or lack of movement, that position the animal in such a way that allows it to hide, freeze, or flee from the supposed predator. Often, an animal's escape response is representative of an instinctual defensive mechanism, though there is evidence that these escape responses may be learned or influenced by experience.
Chordotonal organs are stretch receptor organs found only in insects and crustaceans. They are located at most joints and are made up of clusters of scolopidia that either directly or indirectly connect two joints and sense their movements relative to one another. They can have both extero- and proprioceptive functions, for example sensing auditory stimuli or leg movement. The word was coined by Vitus Graber in 1882, though he interpreted them as being stretched between two points like a string, sensing vibrations through resonance.
Sexual conflict or sexual antagonism occurs when the two sexes have conflicting optimal fitness strategies concerning reproduction, particularly over the mode and frequency of mating, potentially leading to an evolutionary arms race between males and females. In one example, males may benefit from multiple matings, while multiple matings may harm or endanger females due to the anatomical differences of that species. Sexual conflict underlies the evolutionary distinction between male and female.
The elevated plus maze (EPM) is a test measuring anxiety in laboratory animals that usually uses rodents as a screening test for putative anxiolytic or anxiogenic compounds and as a general research tool in neurobiological anxiety research such as PTSD and TBI. The model is based on the test animal's aversion to open spaces and tendency to be thigmotaxic. In the EPM, this anxiety is expressed by the animal spending more time in the enclosed arms. The validity of the model has been criticized as non-classical clinical anxiolytics produce mixed results in the EPM test. Despite this, the model is still commonly used for screening putative anxiolytics and for general research into the brain mechanisms of anxiety.
The somatosensory system is a subset of the sensory nervous system responsible for the perception of touch. Touch is a somatic sense in contrast to the special senses of sight, smell, taste, and hearing and balance.
A sense is a biological system used by an organism for sensation, the process of gathering information about the surroundings through the detection of stimuli. Although, in some cultures, five human senses were traditionally identified as such, many more are now recognized. Senses used by non-human organisms are even greater in variety and number. During sensation, sense organs collect various stimuli for transduction, meaning transformation into a form that can be understood by the brain. Sensation and perception are fundamental to nearly every aspect of an organism's cognition, behavior and thought.
There is a scientific debate which questions whether crustaceans experience pain. It is a complex mental state, with a distinct perceptual quality but also associated with suffering, which is an emotional state. Because of this complexity, the presence of pain in an animal, or another human for that matter, cannot be determined unambiguously using observational methods, but the conclusion that animals experience pain is often inferred on the basis of likely presence of phenomenal consciousness which is deduced from comparative brain physiology as well as physical and behavioural reactions.
Sensory map is an area of the brain which responds to sensory stimulation, and are spatially organized according to some feature of the sensory stimulation. In some cases the sensory map is simply a topographic representation of a sensory surface such as the skin, cochlea, or retina. In other cases it represents other stimulus properties resulting from neuronal computation and is generally ordered in a manner that reflects the periphery. An example is the somatosensory map which is a projection of the skin's surface in the brain that arranges the processing of tactile sensation. This type of somatotopic map is the most common, possibly because it allows for physically neighboring areas of the brain to react to physically similar stimuli in the periphery or because it allows for greater motor control.
Pain in invertebrates is a contentious issue. Although there are numerous definitions of pain, almost all involve two key components. First, nociception is required. This is the ability to detect noxious stimuli which evokes a reflex response that moves the entire animal, or the affected part of its body, away from the source of the stimulus. The concept of nociception does not necessarily imply any adverse, subjective feeling; it is a reflex action. The second component is the experience of "pain" itself, or suffering—i.e., the internal, emotional interpretation of the nociceptive experience. Pain is therefore a private, emotional experience. Pain cannot be directly measured in other animals, including other humans; responses to putatively painful stimuli can be measured, but not the experience itself. To address this problem when assessing the capacity of other species to experience pain, argument-by-analogy is used. This is based on the principle that if a non-human animal's responses to stimuli are similar to those of humans, it is likely to have had an analogous experience. It has been argued that if a pin is stuck in a chimpanzee's finger and they rapidly withdraw their hand, then argument-by-analogy implies that like humans, they felt pain. It has been questioned why the inference does not then follow that a cockroach experiences pain when it writhes after being stuck with a pin. This argument-by-analogy approach to the concept of pain in invertebrates has been followed by others.
In animal physiology, hydrodynamic reception refers to the ability of some animals to sense water movements generated by biotic or abiotic sources. This form of mechanoreception is useful for orientation, hunting, predator avoidance, and schooling. Frequent encounters with conditions of low visibility can prevent vision from being a reliable information source for navigation and sensing objects or organisms in the environment. Sensing water movements is one resolution to this problem.
A behaviour mutation is a genetic mutation that alters genes that control the way in which an organism behaves, causing their behavioural patterns to change.
In zoology, copulation is animal sexual behavior in which a male introduces sperm into the female's body, especially directly into her reproductive tract. This is an aspect of mating. Many aquatic animals use external fertilization, whereas internal fertilization may have developed from a need to maintain gametes in a liquid medium in the Late Ordovician epoch. Internal fertilization with many vertebrates occurs via cloacal copulation, known as cloacal kiss, while most mammals copulate vaginally, and many basal vertebrates reproduce sexually with external fertilization.
Communication occurs when an animal produces a signal and uses it to influences the behaviour of another animal. A signal can be any behavioural, structural or physiological trait that has evolved specifically to carry information about the sender and/or the external environment and to stimulate the sensory system of the receiver to change their behaviour. A signal is different from a cue in that cues are informational traits that have not been selected for communication purposes. For example, if an alerted bird gives a warning call to a predator and causes the predator to give up the hunt, the bird is using the sound as a signal to communicate its awareness to the predator. On the other hand, if a rat forages in the leaves and makes a sound that attracts a predator, the sound itself is a cue and the interaction is not considered a communication attempt.