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RESEARCH INTERESTS
Neuroethology
Neural basis of electrosensory behaviors in weakly electric fish
Acoustic communication in anurans
Neural mechanisms of audition
Behavioral and physiological determinants of sex and coloration in marine wrasses
Song learning in songbirds
PUBLICATIONS
Posters
Na+ channels of midbrain electrosensory neurons in Eigenmannia
Social control of sex and coloration in captive Bluehead wrasses
Song development in white-crowned sparrows tutored with phrase pairs
Temporal integration in the anuran midbrain
We study animal behavior at both 'proximate' and
'ultimate' levels. At the proximate level, we investigate
how neural circuits in fish and anuran amphibians control
natural behaviors. At the ultimate level, we study the
adaptive significance and evolution of these behaviors.
Our research methodology, therefore, ranges from
neurophysiological analysis of single neuron function to
behavioral studies in the lab and field. Behavioral
studies allow us to generate testable hypotheses
concerning neural control. Conversely,
neurophysiological experiments provide clues as to the
evolution of behaviors. This 'neuroethological' approach
is evident in the specific research projects described
below.
Neural control and evolution of electrosensory
behaviors in electric fish
In many animal behaviors, information about the
environment is detected by sensory receptors and then
transmitted to the central nervous system where
stimulus patterns of relevance must be discriminated.
Often, sensory signals are then translated into motor
commands. The cellular mechanisms by which these
operations are performed are poorly understood. Electric
fish are particularly suitable for studying these
questions. Behaviors such as the 'jamming avoidance
responses' remain intact in neurophysiological
preparations, permitting analysis of the entire neural
circuit for generating these behaviors. Presently, we are
using newly-developed methods for making intracellular
recordings in vivo (see ref. below) to investigate
how particular computations are performed. Recently we
have found that short-term synaptic plasticity
mechanisms are important in generating neural filters of
temporal information.
Comparative neurophysiological studies of the
electrosensory system of closely related species that
lack jamming avoidance responses are also in progress.
These studies should shed light on how neural circuits
change during evolution to generate new behaviors.
Behavioral ecology of anurans
Mating strategies of animals are diverse and complex. In
a particularly intriguing case, conspecific males
aggregate during the breeding season into 'leks'. Females
are attracted to these sites and select a mate from the
consort of displaying males.
In anuran species that exhibit this type of mating
system, males aggregate in 'choruses'; their
vocalizations play important roles, such as attracting
females and competing with other males for calling
space.
In collaboration with Dr. Eliot Brenowitz, at the
University of Washington, we have focused recently on
plasticity of vocal behavior of male Pacific treefrogs.
These studies have shed light on the dynamics of chorus
structure and the roles that females play in its
evolution.
Song learning in songbirds
In collaboration with Franz Goller's lab, we are studying how songbirds
learn their songs. Songbirds must hear song early in life in order to later
develop a good copy of the song of their local dialect; they are not
innately able to produce a correct song. During song development, birds
compare what they produce to the memorized representation (template) of the
song(s) that they heard during their 'sensitive period' early in life. We
are currently studying song learning in the species of white-crowned
sparrows that is found in our local mountains. Our work is directed at
exploring the nature of the 'template', how experience shapes it, and how it
is used to guide song development. Recent advances in digital signal
processing now enable us to track the developmental paths that these birds
take in producing complete song.
Neural mechanisms of audition in anurans
Acoustic communication plays an important role in the
reproductive behavior of anuran amphibians (frogs and
toads). Much of the information in these vocalizations is
encoded in the temporal structure (e.g. pulse repetition
rate). The anuran auditory system, therefore, is well
suited for investigating how the temporal structure of
sound is represented at various stages in the auditory
nervous system. We are particularly interested in
understanding the mechanisms that underlie
transformations in these representations. For example,
the periodic modulations in the amplitude of sound are
coded in the peripheral auditory system by the periodic
fluctuations in the discharge rate of these neurons. At
the midbrain, however, this 'periodicity' coding is
replaced by a 'temporal filter' coding scheme wherein
individual neurons selectively respond to particular
rates of amplitude modulation. The mechanisms that
underlie this transformation are unknown. In many cases, transformations result in neurons that respond with great selectivity to particular temporal features of sound. Neurophysiological and behavioral studies have indicated that integration and 'recovery' processes contribute to the temporal selectivity of midbrain neurons. Recent 'whole-cell patch' (intracellular) recordings suggest that interplay between excitation, inhibition and synaptic plasticity underlie selectivity for temporal features of sounds.
Social control of sex, behavior and coloration in
wrasses
Wrasses are coral-reef fishes that exhibit highly plastic
reproductive behavior and life histories. Individuals
begin life in an 'initial phase', wherein males and
females are similarly cryptically colored. Later in life,
particular individuals may undergo a transformation,
becoming more brilliantly colored and, if genetically
female, switch sex. These 'supermales' maintain control
over a harem of females. We are currently studying the
social factors that govern the decision to undergo this
transformation. Eventually, we hope to understand the
physiological processes that underlie this change.
Selected Publications
Leary CJ, Edwards CJ, Rose GJ (2008) Midbrain auditory neurons integrate excitation and inhibition to generate duration selectivity: an, in vivo, whole-cell patch study in anurans. J. Neurosci. In press.
Edwards CJ, Leary CJ, Rose GJ (2007) Counting on inhibition and rate-dependent excitation in the auditory system. J. Neurosci. 27:13384-13392.
Rose, GJ, Goller, F, Gritton, HJ, Plamondon, SL, Baugh AT, Cooper BG (2004) Species-typical songs in white-crowned sparrows tutored with only phrase pairs. Nature 432:753-758.
Fortune ES, Rose GJ (2003) Voltage-Gated NA+ Channels Enhance the Temporal Filtering Properties of Electrosensory Neurons in the Torus. J Neurophysiol. 90:924-929
Edwards CJ, Alder TB, Rose GJ (2002) Auditory midbrain neurons that count. Nature Neuroscience 5(10):934-936
Rose GJ, Brenowitz EA (2002) Pacific Tree Frogs Use Temporal Integration to Different Advertisement from Encounter Calls. Animal Behavior 63:1183-1190
Fortune, E.S. and G.J. Rose (2001) Short-term synaptic
plasticity as a temporal filter. Trends in Neurosciences.
24(7): 381-385.
Alder TB, Rose GJ (2000) Integration and recovery
processes contribute to the temporal selectivity of neurons
in the northern leopard frog, Rana pipiens. J. Comp. Physiol.
186: 923-937.
Fortune ES, Rose GJ (2000) Short-term plasticity
contributes to the temporal filtering of electrosensory
information. J. Neurosci. 20:7122-7130.
Alder TB, Rose GJ (1998) Long-term integration in the
anuran auditory system. Nature Neuroscience 1(6): 519-
523.
Rose, G. J., and E. A. Brenowitz. (1997) Plasticity of
aggressive thresholds in male Pacific treefrogs: Discrete
accommodation to the encounter call. Animal Behav. 53:
353-361.
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