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I N D I A N A   U N I V E R S I T Y
A N I M A L B E H A V I O R  C O N F E R E N C E  2 0 0 4

APRIL 22, 2004
8:00AM-12:00PM
Dogwood Room
Indiana Memorial Union
Indiana University
Bloomington, Indiana, USA

Sponsored by the Center for the Integrative Study of Animal Behavior


CONFERENCE PROGRAM

sponsored by
Center for the Integrative Study of Animal Behavior
Dogwood Room, Indiana Memorial Union

THURSDAY, APRIL 22

8:00am Coffee available outside door of Dogwood Room
8:15am Welcome by George Rebec, Department of Psychology, Program of Neural Science, Director

Session I.
moderator: Hanna Kolodziejski

8:30am
“Context-dependent behavioral and electro-physiological sensitization to sub-chronic 3,4-methylenedioxymethamphetamine (MDMA) administration in freely-moving rats".
Kevin Ball

8:45am
“Damselfly response to simulated drought and implications for sexual selection".
Idelle Cooper

9:00am
"Contact pheromones in the German cockroach (Blattella germanica): More than just about sex".
Dorit Eliyahu

9:15am
“Superstition re-revisited: An examination of niche-related mechanisms underlying schedule produced behavior in Pigeons”.
Eduardo Fernandez

9:30am
"Estimating hominid home range sizes from cranial capacity data".
Shawn Hurst

9:45am
"The evolution of color pattern morphology of the true chameleons (family Chamaeleonidae)".
Erin Kelso

10:00am Coffee Break

Session II.
moderator: Thalia Brine

10:15am
"Sex and species differences in neuromodulatory input to a premotor nucleus: A comparative study of substance P and communication behavior in weakly electric fish".
Johanna Kolodziejski

10:30am
“Non-domesticated animals as models for neuroendocrine mechanisms of anxiety and depression".
Kate Semsar

10:45am
“Experience matters: The impact of differential environmental exposure on behavioral responding for reinforcement”.
David Wood

11:00am
"Effects of testosterone on female aggression, corticosterone, and immune function: Evidence for intersexual conflict in dark-eyed juncos".
Devin Zysling

11:15am
Award Ceremony

11:30am
"Multiple mechanisms of male phenotype development as adaptations to predictable and unpredictable environmental change".
John Godwin

Lunch
Graduate students will join Keck Center guest speakers for lunch following the conference.

Campus & Lab Tours for Keck Center students
Lunch groups will meet at CISAB at 2:00pm.

Reception
Everyone is invited to attend a reception at Laura Hurley and Troy Smith’s at 7:00pm. Maps will be available at the conference. Please bring a dish to share.

ABSTRACTS

Context Dependent Behavioral and Electriophysiological Sensitization to Sub-Chronic 3, 4-Methylenedioxymethamphetamine (MDMA) Administration in Freely Moving Rats
Kevin. T. Ball
Department of Psychology, Indiana University

We recently characterized the striatal single-unit response to acute 3, 4 methylenedioxy methamphetamine (MDMA) in freely moving animals (Ball et al., 2003, Brain Res., v. 994, p. 203). To further investigate the neuronal mechanisms underlying the behavioral response to MDMA, we recorded the activity of > 100 single units in the striatum of freely moving rats in response to a locomotor-activating dose (5 mg/kg) of sub-chronic MDMA. Rats were treated with once daily injections of either saline or MDMA for five days in their home cage, followed by a challenge injection 3-4 days later in a recording chamber. Because contextual drug associations may be particularly important to the expression of behavioral sensitization to chronic MDMA, a separate group of rats received repeated injections of MDMA alternately in the recording chamber or home cage, according to the above timeline. A sensitized locomotor response was observed only in rats that had previously experienced MDMA in the context of the recording chamber, and only on the challenge day. These sensitized animals also showed a decreased basal firing rate in neurons that were subsequently excited by MDMA when compared to the same category of neurons earlier in the treatment regimen. This resulted in a greater percent increase from baseline firing rate on the challenge day compared to the first and fifth days of treatment, even though this trend was not evident with an analysis of absolute firing rate. In all treatment groups, MDMA had a predominantly excitatory effect on neuronal activity that was positively correlated with the magnitude of locomotor activation; however, this correlation decreased progressively across treatment days in the sensitized animals. These results strongly support a role for context in the expression of MDMA-induced locomotor sensitization, and suggest some important neuronal adaptations that may contribute to this behavioral change. Given that a connection has been established between sensitization and drug seeking behavior, these electrophysiological correlates may have broader implications in the field of drug addiction research.

Damselfly Response to Simulated Drought and Implications for Sexual Selection
Idelle Cooper
Department of Biology, Indiana University

The sensitive nature of tropical climates to global climatic change is an important focus of efforts to identify current ecological responses to global warming and to predict future change. This study addresses ecological consequences of drought by examining the responses of the endemic Hawaiian damselfly species Megalagrion calliphya (Odonata: Coenagrionidae) to simulated drought in the tropical cloud forest of Hawaii Volcanoes National Park. I monitored adult mating behavior and larvae size after altering the availability of aquatic breeding and oviposition sites. The ability of damselflies to obtain mates was particularly impacted by the size, health, and permanence of water sources. In examining male mating behavior, we observed that rather than dispersing with increased male density at the diminished water sources, male territory size decreased and males occupied formerly undesirable sites. In addition, the amount of fighting between males for territories increased with drought. A survey of the larvae resulting from the mating interactions after simulated drought indicated that the total number of larvae was greatest in the largest pools. There were relatively more larvae in areas with more water relative to the number of territorial males in those areas. This difference may indicate that females mated preferentially with the males in those areas and consequently oviposited in those ponds. In addition, larva density was highest in the smallest ponds, and those larvae were also the smallest. These larvae likely encounter greater environmental stress due to increased competition and harsher abiotic conditions. The smaller pools had greater temperature fluctuations and oxygen rate of change throughout the day, as well as lower specific conductivity. The changes in mating behavior and larva development that we observed have important implications for longer-term changes in the damselfly species, particular in mate choice and larva competition.

Contact Pheromones in the German Cockroach Blattella germanica: More than just about Sex
Dorit Eliyahu
Department of Entomology, North Carolina State University

The German cockroach male exhibits a typical courtship behavior upon contact with a sexually mature female. The behavior, which includes raising of the wings, can be elicited by contact of the male’s antennae with an isolated female antenna or with a male antenna treated with 3,11-dimethylnonacosan-2-one, the main component of the female contact sex pheromone. This compound has four stereoisomers, but their relative effectiveness at releasing courtship in males has not been delineated through dose-response studies. The four stereoisomers of the C29 methyl ketone were synthesized and behaviorally assayed, and we show here that (3S,11S), the natural isomer, is surprisingly, the least effective of the four stereoisomers. This is the first evidence of an unnatural stereoisomer being a better releaser of behavior than the natural isomer. It suggests that geographically separated populations of the German cockroach might have diverged in their use of pheromonal stereoisomers. A related compound, 3,11-dimethylheptacosan-2-one has been isolated from virgin females and found to elicit courtship in males. Using a synthetic (3S,11S) C27 methyl ketone, the presumed natural stereoisomer, we confirm that this compound is behaviorally active. As expected, higher concentrations of the C27 methyl ketone are required than the C29 dimethyl ketone to elicit equivalent responses. It can therefore be considered another component of the female contact sex pheromone blend. Newly emerged females, males and nymphs can also stimulate males to exhibit sexual behavior. Our results indicate that, unlike males, who lose their ability to stimulate courtship behavior in mature males within several days after the adult molt, nymphs retain this capacity throughout the last instar. We are using chromatographic approaches to isolate and identify this pheromone. Thus far, this pheromone appears to be different from the female pheromone. The adaptive significance of this communication system in nymphs and young adults remains to be elucidated.

Superstition Re-revisited: An Examination of Niche-Related Mechanisms Underlying Schedule Produced Behavior in Pigeons
Eduardo J. Fernandez
Department of Psychology, Indiana University

In 1948, Skinner described as superstitious the responses of pigeons produced by fixed-time (FT) schedules, under which food is delivered at fixed times, independent of behavior. Skinner argued that responses accidentally occurring immediately prior to the delivery of food were reinforced, and therefore more likely to occur (and be rewarded) in the future. In support of his interpretation, Skinner described a number of presumably idiosyncratic response patterns that emerged in individual pigeons. Subsequently, both Staddon and Simmelhag (1971) and Timberlake and Lucas (1985) examined this phenomenon, and concluded that the behaviors were not idiosyncratic, but were closely related to the action of food in eliciting species-typical behavior. The following studies were conducted to further contrast superstitious versus functional interpretations of behavior under FT schedules. Experiment 1 examined the effects of repeated extinctions interspersed between FT schedules in pigeons. Experiment 2 examined the behavior of bantam chickens (Gallus gallus) and Experiment 3 looked at the behavior of ring-necked doves (Streptopelia capicola) and roller pigeons (Columba livia), all under similar FT schedules. Experiment 4 compared male and female pigeons under similar FT schedules. Experiment 5 examined the effects of the laboratory box size on pigeon behavior under FT schedules. All four experiments supported the Timberlake and Lucas (1985) hypothesis that the behavior of pigeons under FT schedules in the laboratory reflect species-related foraging behavior, rather than idiosyncratic response produced by chance contingencies (Skinner, 1948), and the terminal response hypothesis of Staddon and Simmelhag (1971). How these data help better understand the underlying niche-related mechanisms involved in laboratory learning will be discussed, as well as future directions.

Estimating Hominid Home Range Sizes from Cranial Capacity Data
Shawn Hurst
Department of Anthropology, Indiana University

Assessing the behavior of extinct primates from the fossil record is notoriously difficult. However, primate body size, group size, home range area, and dietary quality are strongly related, and can be used to predict average neocortex size for most primate species. Here I use these relationships in reverse fashion, along the body size estimates for several hominid fossils and the known relationship between primate neocortex size and cranial capacity, to estimate the average home range and group size for several hominid species. When comparing these with the archaeological record and savannah baboon (Papio cynocephalus) and chimpanzee (Pan troglodytes) data, this model suggests that Australopithecines were not that behaviorally different than modern great apes, but that home range, dietary quality, and group size increased abruptly with the advent of Homo habilis, and suggests there may have been large differences in social group and home range size between earlier versus later groups of Homo erectus.

The Evolution of Color Pattern Morphology of the True Chameleons (Family Chamaeleonidae)
Erin Kelso
Department of Biology, Indiana University

The true chameleons (family Chamaeleonidae) are recognized for their unique adaptations, including the ability to undergo rapid color changes that facilitate social communication. Very little research, however, has addressed the evolution of color pattern morphology or their use in communication. As a first step, we scored published photos for presence or absence of color pattern elements and morphological traits that may be important in signaling. We identified color patterns based on their similarity of appearance, including position on the body, and classified them based on their distribution within the genus. We find that very few clades (3) can be identified by unique color pattern or morphological traits. Instead, most clades (8) may be identified by a specific combination of traits. These results suggest that the majority of color pattern elements evolved before the Madagascar and mainland African genera separated.

Sex and Species Differences in Neuromodulatory Input to a Aremotor Nucleus: A Comparative Study of Substance P and Communication Behavior in Weakly Electric Fish
Hanna Kolodziejski
Department of Biology, Indiana University

Many electric fish species modulate their electric organ discharges (EODs) to produce transient social signals that vary in number and structure. In Apteronotus leptorhynchus, males modulate their EOD more often than females, whereas in Apteronotus albifrons, males and females produce similar numbers of modulations. Sex differences in the number of EOD modulations in A. leptorhynchus are associated with sex differences in substance P in the diencephalic nucleus that controls transient EOD modulations, the CP/PPn. These sex differences in substance P have been hypothesized to regulate sex differences in the production of EOD modulations. To comparatively test this hypothesis, we examined substance P immunoreactivity in the CP/PPn of male and female A. leptorhynchus and A. albifrons. Because the number of EOD modulations is sexually monomorphic in A. albifrons, we predicted no sex difference in substance P in the CP/PPn of this species. Contrary to this prediction, male A. albifrons had significantly more substance P in the CP/PPn than females. This suggests that sex differences in substance P are not sufficient for controlling sex differences in the number of EOD modulations. Modulation structure (frequency excursion and/or duration), however, is also sexually dimorphic in A. leptorhynchus and is another possible behavioral correlate of the sexually dimorphic distribution of substance P. The present study found pronounced sex differences in the structure of EOD modulations in A. albifrons similar to those in A. leptorhynchus. Thus, sex differences in substance P may influence sex differences in the structure, rather than the number, of EOD modulations.

Non-Domesticated Animals As Models For Neuroendocrine Mechanisms of Anxiety and Depression
Katharine Semsar
Department of Zoology, North Carolina State University

In depression, arginine vasopressin (AVP) is often elevated, especially in patients with anxiety-related depression. The importance of these elevated AVP levels may be AVP’s ability to drive the hypothalamo-pituitary axis under conditions of chronic stress. While SSRI (selective serotonin reuptake inhibitor) antidepressants can normalize AVP levels and relieve depression, the exact mechanism has proven difficult to study since most rodent models fail to show this effect of SSRIs on AVP levels. However, recently researchers have developed a ‘high anxiety behavior’ rat strain that, unlike ‘low anxiety behavior’ and standard laboratory rat strains, has elevated AVP expression and shows a reduction in AVP expression when treated with an SSRI. Interestingly, wild bluehead wrasses (Thalassoma bifasciatum) show this same decrease in AVT expression (the non-mammalian homologue to AVP) in response to SSRI treatment. In these fish’s natural environment of high predation threat, frequent aggressive interactions, and continuous social change, a sensitive stress response and “anxious behaviors” may be advantageous. Since domestication of laboratory models often breeds towards a desensitized stress response, this may explain the usual failure of laboratory rodents to respond to antidepressant drugs which target a further desensitization of the stress response. Therefore, animals that can show a strong response to stressors may be particularly useful for studying neuroendocrine mechanisms of depression. We are currently testing this idea by measuring the stress response and effect of SSRI treatment on AVP expression in wild mice and voles and comparing these responses to those of their corresponding domesticated or semi-domesticated laboratory strains.

Experience Matters: The Impact of Differential Environmental Exposure on Behavioral Responding for Reinforcement
David Wood
Department of Psychology, Indiana University

Behavioral differences have been reported in rats raised under environmentally enriched (EE) conditions relative to littermates placed in less stimulating, socially isolated (SI) environments. Although EE rats are generally understood to be superior learners to SI animals, several reports conflict with this finding. To assess the impact of differential environmental exposure on learning, we trained EE and SI animals in an operant task for sucrose reinforcement. Our results indicate that increased impulsive responding to operant stimuli but not generalized hyperactivity contribute to learning-related differences. These results indicate that “elevated gain” on approach responding for reward in SI animals may compete with the formation of complex associations and thus result in attenuated learning rates in appetitive contexts where complex contingencies operate.

Effects of Testosterone on Female Aggression, Corticosterone, and Immune
Devin Zysling
Department of Biology, Indiana University

Intersexual conflict occurs when a trait that is beneficial to one sex is costly to the other. Conflict can be resolved through the evolution of sex- limited expression, and, in vertebrates, testosterone (T) often mediates traits in males that may fail to be expressed in females or be expressed to a lesser degree. Surprisingly little is known, however, about the role of testosterone in female vertebrates, and whether effects of T in females might constrain the evolution of T-mediated traits in males. We sought to evaluate the potential for intersexual conflict by examining the impact of experimental elevation of T on the behavior and physiology of female dark-eyed juncos. Using a wild-caught captive population, we implanted birds with silastic capsules that were either empty (C-females) or filled with testosterone (T-females). Birds were housed individually in an outdoor aviary and were injected with the antigen SRBC, bled, and observed. Using a standard resident-intruder model, we placed a novel female intruder into the compartment of an experimental female and observed behavior. We then quantified the frequency of kews (aggressive vocalizations), approaches (chases and active displacements), and flutter-ups performed by the experimental female. We found that T-females displayed significantly more kews and approaches as compared to C-females and tended towards more flutter-ups. Our results suggest that, similarly to males, females display increased aggression when treated with T. We are currently examining the effects of T on immune function and corticosterone release, and these results will be discussed.

Multiple Mechanisms of Male Phenotype Development as Adaptations To Predictable and Unpredictable Environmental Change
John Godwin
Department of Zoology, North Carolina State University

Animals are faced with two types of changing circumstances to which they must adapt their behavior. Adaptation to predictable changes such as those associated with growth or seasonal cycles appear likely to be mediated by different mechanisms than those for unpredictable changes such as storms or rapid social change. We have been studying neuroendocrine mechanisms underlying behavioral adaptation in a coral reef fish, the bluehead wrasse (Thalassoma bifasciatum) that exhibits remarkable plasticity in reproductive function and behavior. Bluehead wrasses exhibit three sexual phenotypes and show strong behavioral variation between them. Females are somewhat cryptically colored, show little aggression, and no courtship behavior. Initial phase (IP) males are female mimics, showing little aggression or courtship and reproducing through either sneaking or group-spawning behaviors. Terminal phase (TP) males are large, colorful, and socially dominant. The degree of aggressive and courtship behavior TP males exhibit depends on whether they hold a territory or not. Bluehead wrasses also show extreme behavioral and sexual plasticity, showing sex, role, and status change in response to growth and changing social conditions. Removal of dominant TP males from small social groups induces behavioral and gonadal sex change in the largest females. We use changes in sex and territorial status to address rapid behavioral adaptation to unpredictable social changes. The behavioral components of sex and role change are correlated with rapid increases in the expression of a neuropeptide hormone, arginine vasotocin (AVT). Despite the rapid gonadal changes that occur during sex change, neither the behavioral changes or changes in AVT expression depend on the type or presence of gonads, being instead determined by social status. Manipulations of the AVT system affect behavior, but effects vary strongly across sexual phenotypes. Consistent with the increases in AVT expression and male-typical aggressive and courtship behavior seen during sex change, we find that AVT appears both necessary and sufficient for developing territorial status among TP males. However, while necessary for females to undergo sex change, AVT is not sufficient to induce aggression or courtship behavior in females or female-mimic IP males. Behavioral adaptations to more predictable change appear to involve a different neuroendocrine mechanism. Females receiving implants of a key androgen, 11-ketotestosterone, and remaining in the presence of a dominant male do not show effects on AVT neuronal phenotype, but do develop TP male typical colors and exhibit opportunistic courtship behavior similar to that of non-territorial TP males. We interpret these different neuroendocrine pathways of male-typical behavioral development as adaptations to differing patterns of change in the social environment and suggest this is likely to be characteristic of species faced with this type of environmental variability.

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