Socioendocrinology of Animal Communication
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Wilczynski
Lab
Socioendocrinology of Animal Communication |
| The acoustic communication system of frogs and toads is a model for investigating the neural and hormonal mechanisms of animal communication. As in many other systems, the vocal exchanges between frogs are part of the seasonal social behavior associated with breeding and have mate attraction and aggressive functions. The Wilczynski Lab is engaged in studying the reciprocal interactions of the communication behavior and hormonal systems. This entails studying the system to understand two interacting aspects of it: How are features of the communication behavior (vocal production, behavioral responses to the calls) controlled by hormones; and, how does the reception of communication signals modify hormonal state? |
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| A
variety of studies have investigated the influence on male calling of
androgen steroid hormones, the peptide hormone arginine vasotocin (AVT),
and the interaction of the two.
Laboratory studies confirm that calling is androgen dependent. Several
other studies have focused on the influence of AVT on male calling
behavior. That research employs a field endocrinology approach, examining
male behavior in natural breeding choruses and the effect of manipulating
AVT levels on males as they vocalize spontaneously or in response to
experimentally presented stimuli. These studies indicate that AVT
increases motivation to call. A recent study investigating the interaction
of AVT with other hormones suggests that AVT does not exert its effect by
either increasing androgen levels or decreasing stress hormone levels. |
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| Graph above shows calling rate in male Hyla cinerea under three hormone conditions. Removing androgens eliminates calling; replacing androgens with testosterone implants stimulates calling. |
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The
complementary side to the hormonal control of communication behavior is the
effect of receiving social communication signals on hormone levels.
Long-term studies in the lab are aimed at identifying the anatomy and
physiology of central nervous system pathways that link the auditory
system with the limbic areas controlling endocrine release. Behavioral
studies based on the neurobiological work have shown that hearing
calls increases androgen levels in male frogs, along with levels of stress
hormones. These hormonal changes are independent of the frog’s own
behavior while hearing the call. Current work investigates central nervous
system changes that correlate with this effect. |
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| Photo at top shows gonadotropin releasing hormone cells in the rostral preoptic area. Photo below it shows test chambers for studying the response to conspecific calls. Graphs at right show the increase in androgens (testosterone and dihydrotestosterone) when green treefrogs (Hyla cinerea) are exposed to the sounds of a treefrog chorus, but not when exposed to tones or silence. |
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Selected Publications
Burmeister,
S., C. Somes, & W. Wilczynski. (2001) Behavioral and hormonal consequences
of exogenous vasotocin and corticosterone in the green treefrog. Gen. Comp.
Endocrinol., 122: 189-197.
Chu,
J., & W. Wilczynski (2001). The social influences on androgen levels in the
southern leopard frog, Rana sphenocephala.
Gen. Comp. Endocrinol., 121: 66-73.
Burmeister,
S., & W. Wilczynski (2000). Social signals influence hormones independently
of calling behavior in the treefrog (Hyla
cinerea). Horm. Behav., 38: 201-209.
Marler,
C.A., S.K. Boyd, & W. Wilczynski (1999). Forebrain neuropeptide correlates
of alternative male mating strategies. Horm. Behav., 36: 53-61.
Chu, J., C. A. Marler, & W. Wilczynski (1998). The effects of arginine vasotocin on the calling behavior of male cricket frogs in changing social contexts. Horm. Behav., 34: 248-261.
Wilczynski,
W., J. D. Allison, and C. A. Marler (1993).
Sensory pathways linking social and environmental cues to endocrine
control regions of the amphibian forebrain.
Brain Behav. Evol, 42:252-264.
Allison, J. D., and W. Wilczynski (1991). Thalamic and midbrain auditory projections to the preoptic area and ventral hypothalamus in the green treefrog (Hyla cinerea). Brain Behav. Evol., 37:322-331.
Wilczynski,
W., and J. D. Allison (1989). Acoustic
modulation of neural activity in the hypothalamus of the leopard frog.
Brain Behav. Evol., 33:317-324.
