Volume 197, Issue 6:
Victoria S. Arch, Sabrina S. Burmeister, Albert S. Feng, Jun-Xian Shen & Peter
M. Narins (2011): Ultrasound-evoked immediate early gene expression in the
brainstem of the Chinese torrent frog, Odorrana tormota. J. Comp. Physiol. A,
197 (6), 667-675.
Abstract: The concave-eared torrent frog, Odorrana tormota, has evolved the
extraordinary ability to communicate ultrasonically (i.e., using frequencies >
20 kHz), and electrophysiological experiments have demonstrated that neurons in
the frog’s midbrain (torus semicircularis) respond to frequencies up to 34 kHz.
However, at this time, it is unclear which region(s) of the torus and what
other brainstem nuclei are involved in the detection of ultrasound. To gain
insight into the anatomical substrate of ultrasound detection, we mapped
expression of the activity-dependent gene, egr-1, in the brain in response to a
full-spectrum mating call, a filtered, ultrasound-only call, and no sound. We
found that the ultrasound-only call elicited egr-1 expression in the superior
olivary and principal nucleus of the torus semicircularis. In sampled areas of
the principal nucleus, the ultrasound-only call tended to evoke higher egr-1
expression than the full-spectrum call and, in the center of the nucleus,
induced significantly higher egr-1 levels than the no-sound control. In the
superior olivary nucleus, the full-spectrum and ultrasound-only calls evoked
similar levels of expression that were significantly greater than the control,
and egr-1 induction in the laminar nucleus showed no evidence of acoustic
modulation. These data suggest that the sampled areas of the principal nucleus
are among the regions sensitive to ultrasound in this species.
URL: http://www.springerlink.com/content/94323413v5281187/
For reprints please contact V. S. Arch (email:
Volume 197, Issue 9:
Raquel O. Vasconcelos, Joseph A. Sisneros, M. Clara P. Amorim & Paulo J.
Fonseca (2011): Auditory saccular sensitivity of the vocal Lusitanian toadfish:
low frequency tuning allows acoustic communication throughout the year. J.
Comp. Physiol. A, 197 (9), 903-913.
Abstract: A novel form of auditory plasticity for enhanced detection of social
signals was described in a teleost fish, Porichthys notatus (Batrachoididae,
Porichthyinae). The seasonal onset of male calling coincides with inshore
migration from deep waters by both sexes and increased female sensitivity to
dominant frequencies of male calls. The closely related Lusitanian toadfish,
Halobatrachus didactylus, (Batrachoididae, Halophryninae) also breeds
seasonally and relies on acoustic communication to find mates but, instead,
both sexes stay in estuaries and show vocal activity throughout the year. We
investigated whether the sensitivity of the inner ear saccule of H. didactylus
is seasonally plastic and sexually dimorphic. We recorded evoked potentials
from populations of saccular hair cells from non-reproductive and reproductive
males and females in response to 15–945 Hz tones. Saccular hair cells were most
sensitive at 15–205 Hz (thresholds between 111 and 118 dB re. 1 μPa). Both
sexes showed identical hearing sensitivity and no differences were found across
seasons. The saccule was well suited to detect conspecific vocalizations and
low frequencies that overlapped with lateral line sensitivity. We showed that
the saccule in H. didactylus has major importance in acoustic communication
throughout the year and that significant sensory differences may exist between
the two batrachoidid subfamilies.
URL: http://www.springerlink.com/content/38g7291555q16442/
For reprints please contact Raquel Vasconcelos (email:
Takeshi Mizumoto, Ikkyu Aihara, Takuma Otsuka, Ryu Takeda, Kazuyuki Aihara &
Hiroshi G. Okuno (2011): Sound imaging of nocturnal animal calls in their
natural habitat. J. Comp. Physiol. A, 197 (9), 915-921.
Abstract: We present a novel method for imaging acoustic communication between
nocturnal animals. Investigating the spatio-temporal calling behavior of
nocturnal animals, e.g., frogs and crickets, has been difficult because of the
need to distinguish many animals’ calls in noisy environments without being
able to see them. Our method visualizes the spatial and temporal dynamics using
dozens of sound-to-light conversion devices (called “Firefly”) and an
off-the-shelf video camera. The Firefly, which consists of a microphone and a
light emitting diode, emits light when it captures nearby sound. Deploying
dozens of Fireflies in a target area, we record calls of multiple individuals
through the video camera. We conduct two experiments, one indoors and the other
in the field, using Japanese tree frogs (Hyla japonica). The indoor experiment
demonstrates that our method correctly visualizes Japanese tree frogs’ calling
behavior. It has confirmed the known behavior; two frogs call synchronously or
in anti-phase synchronization. The field experiment (in a rice paddy where
Japanese tree frogs live) also visualizes the same calling behavior to confirm
anti-phase synchronization in the field. Experimental results confirm that our
method can visualize the calling behavior of nocturnal animals in their natural
habitat.
URL: http://www.springerlink.com/content/uh240559280h7875/
For reprints please contact T. Mizumoto (email:
Kind regards
Sonja Amoser
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Dr. Sonja Amoser
Steinrieglstraße 286
3400 Weidlingbach
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