Summary: Researchers have discovered that animals use their saccule, a part of the inner ears associated with harmony, to find low-frequency waves. This visual pathway enhances their regular reading and may be present in different reptiles.
The study provides new insights into how animal sensory systems evolved as a result of showing that iguanas may identify vibrations between 50 and 200 Hz. This discovery raises questions about whether specific reptiles are “dead” and opens up new avenues for studying vibrational interaction among them.
Important Information:
- Geckos detect low-frequency motions using their internal tongue’s saccule.
- This visual capacity may be present in various reptiles that were originally thought to have limited hearing.
- The study provides insight into how canine sensory systems changed over time.
Origin: University of Maryland
What we thought we knew about dog reading is being shook up by University of Maryland researchers who discovered a hidden visual skills in animals.
In a fresh research published in , Present Biology , on October 4, 2024, the researchers revealed that animals use the saccule—a portion of their inner ear typically associated with maintaining balance and body positioning—to find low-frequency waves.
This unique” sixth sense” also, according to the researchers, complements the geckos ‘ regular hearing and their ability to sense the world around them.
The team believes that this earlier undiscovered hearing mechanism may also be present in other reptile species, challenging earlier theories about how pet sensory systems evolved and changed over time.
” The ears, as we know it, hears flying sound. But this old inside road, which is commonly linked to compromise, helps geckos detect vibrations that journey through mediums like the ground or water”, said study co-author , Catherine Carr, a Distinguished University Professor of Biology at UMD.
This route is present in both amphibians and bass, and lizards have recently shown it to be preserved as well. Our findings reveal how the audio program changed from what you can see in fish to what you can see in land animals, including people.
The saccule may find subdued waves between 50 and 200 Hz, which is typically heard by geckos through their ears. According to researchers, this suggests that the saccule serves a different but complementary function in addition to the geckos ‘ typical audio program. Some other reptiles are unable to hear flying sound, unlike geckos, which are able to do so.
The study’s lead author, Dawei Han, a postdoctoral scholar and former student scholar at UMD, claims that the finding of the saccule’s part in reptile reading may lead to a better understanding of communication and behavior in other animals originally thought to have limited audio abilities.  ,
In the sense that they do not vocalize or hear sounds well, Han explained,” a lot of snakes and lizards were thought to be’mute’ or ‘deaf’. However, it turns out that they could be communicating with vibrational signals using this sensory pathway instead, which significantly alters how animal scientists have overall viewed animal perception.
This shared sensory pathway in contemporary reptiles provides a unique insight into the evolution of vertebrate sensory systems, suggesting that the transition from aquatic to terrestrial environments likely involved more intricate and gradual changes in hearing mechanisms than previously thought.
Although these findings are not directly related to how people hear, the researchers think that there is always more than meets the eye—or, in this case, ear.
” Think about when you’re at a live rock concert”, Carr said. You can feel your entire head and body vibrating in the sound field because it is so loud. Instead of just hearing the music, you can feel it. That perception suggests that those loud concerts may stimulate the human vestibular system, which may indicate that our sense of balance and hearing may also be closely linked.”
Carr and Han hope that their findings will lead to more investigations into mammalian hearing, especially in the context of this sensory pathway. They think that the link between balance and hearing opens up new research avenues, including the link between balance disorders in people.
” The implications of this research extend beyond the world of reptiles”, Han said. ” As we uncover these hidden mechanisms, we’re also gaining a richer and more nuanced picture of how animals perceive and interact with their environments—and potentially, new insights into our own sensory experiences”.
Funding: This study received funding from the National Institutes of Health ( Grant No. R01DC019341 ).
About this news from neuroscience research in auditory perception
Author: Georgia Jiang
Source: University of Maryland
Contact: Georgia Jiang – University of Maryland
Image: The image is credited to Neuroscience News
Original Research: Open access.
” The tokay gecko’s auditory pathway for the detection of vibration” by Catherine Carr et al. Current Biology
Abstract
The tokay gecko’s auditory pathway for the detection of vibration
With little evidence to support the auditory function found in fish and amphibians ( frogs and salamanders ), otolithic endorgans like the saccule were thought to be strictly vestibular in amniotes ( reptiles, birds, and mammals ).
Here, we show the saccule’s auditory function in the tokay gecko ( Gekko gecko ).
The hindbrain’s nucleus vestibularis ovalis ( VeO ) projectes through an ascending pathway parallel to cochlear pathways and only receives input from the saccule. Single-unit recordings show that VeO is exquisitely sensitive to low-frequency vibrations.
Moreover, VeO is present in other lepidosaurs, including snakes and , Sphenodon. These findings support the hypothesis that the saccule’s ancestral auditory function is probably still present in the amniotes ‘ lepidosaurian lineage and mediates sensitive vibration encoding.
