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| International Symposium - Behavior Analysis and Biomedical Science |
| Monday, May 29, 2006 |
| 1:30 PM–2:50 PM |
| Montreal |
| Area: EAB; Domain: Basic Research |
| Chair: M. Christopher Newland (Auburn University) |
| Abstract: Behavioral methods and measures are making inroads into biomedical science and are providing theory-based assessments of behaviour that are useful in the assessment of many biomedical questions – and in enhancing the appreciation of behaviour as essential to understanding the dynamics between insult or injury and outcome. Equally, biomedical research is beginning to help us redefine our understanding of learning and behavior. We present two empirical papers that relate prenatal undernutrition to adult behavior, one focused on changes in reinforcer effectiveness, and the other on learning difficulties and preference for exercise. We also present recent results concerning mercury, dopamine receptors and schedule performance, and we consider the implications for learning of the activation of glutamate NMDA and dopamine D1 receptors. From a more general viewpoint, we will also discuss the question of reductionism and behaviour analysis. |
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| Effects of Prenatal Food Restriction on Reinforcer Efficacy and the Cannabinoid System. |
| ERIN B. RASMUSSEN (Idaho State University), Daniel Selvage (Idaho State University), Alexa A. Wakley (Idaho State University), Shilo L. Smith Ruiz (Idaho State University) |
| Abstract: Prenatal food restriction is linked to low birth weight and length, and later to increased risk of obesity and obesity-related illnesses, including cardiovascular disease and type-II diabetes. A wealth of experimental and epidemiological data has been garnered on the neuroendocrinology of prenatal food restriction’s effects, and the long-term physiological changes in the organism which are primarily related to alterations in biochemical sensitivity to hunger and satiety signals. However, few behavioral data exist on how these changes manifest as everyday operant behavior. One possible behavioral mechanism for overeating may be that the reinforcing properties of food are stronger in prenatally food restricted rats than in controls. The data presented here demonstrate that prenatal food restriction leads to lasting biochemical changes (e.g., changes in leptin, a satiety hormone, as well as the cannabinoid system, which is linked to feeding) that manifest as persistent changes in the reinforcing efficacy of food. |
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| Early-life Nutrition and Behavior. |
| CHRISTIAN ULRICH KRAGELOH (University of Auckland, New Zealand), Michael C. Davison (University of Auckland, New Zealand), Jason Landon (University of Auckland, New Zealand), Nichola Thompson (The Liggins Institute), Bernhard Breier (The Liggins Institute) |
| Abstract: Our research group investigates the effects of pre- and postnatal nutrition on learning and behavior in adulthood. Offspring of undernourished mothers are significantly smaller at birth and are more likely to develop obesity after puberty. In several independent studies, we investigated the long-term effects of fetal undernutrition in the rat, as well as the effects of a postnatal high-fat diet, on learning in a frequently changing environment, preference for food versus exercise, and self control and preference reversal. |
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| Clocks and Dopamine: Drug Effects on Behavior under Clocked and Unclocked FI Schedules. |
| MIRANDA REED (Auburn University), M. Christopher Newland (Auburn University) |
| Abstract: Behavior under strong stimulus control is sometimes resistant to drug challenges and dopamine pathways may be involved with this resistance. We examined the effects of gestational MeHg, which influences catecholamines, on behavior under FI schedules and the acute effects of drugs that affect catecholamine neurotransmitter systems. Female rats exposed gestationally to MeHg lever-pressed under a MULT FI 120" (Clock) FI 120" (NoClock) schedule of sucrose reinforcement. The "Clock" component contained 5, 24" bins, each associated with a different auditory stimulus. During baseline, the Clock component maintained lower rates relative to the NoClock in the early portion of the interval. The clock protected against response rate increases early in the FI produced by desipramine and a D1 agonist. The clock conferred no protection against rate increases produced by cocaine or a D2 agonist or against rate decreases by any drug at the end of the FI. MeHg exposure altered sensitivity to some drugs in both the clock and no-clock components. Noradrenergic or D1 agonists increased low response rates and exteroceptive stimuli protected against these rate-increasing effects. The clock exerted no protection against D2 agonists. Antagonists only decreased response rates under all conditions. Research supported by NIEHS 10865. |
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| Neuroscience meets Sniffy: Lever-Press Shaping Requires D1 and NMDA Receptor Activation in a Distributed Corticostriatal Network. |
| MATTHEW E. ANDRZEJEWSKI (University of Wisconsin, Madison) |
| Abstract: From a behavioral neuroscience perspective, learning is generally thought of in terms of the long-term neural changes that result from experience, rather than the long-term changes in behavior, which may be said to be the focus of behavior analysis. However, these two positions are not mutually exclusive; they focus on two different aspects of the same phenomena. An emerging model of those long-term physiological changes, or neural plasticity, involves activation of glutamate NMDA and dopamine D1 receptors in a widely distributed network of brain structures. The results of several experiments demonstrate that NMDA and D1 receptor activation, in a distinct neural network, is indeed required for the initial shaping of a rat's lever-press and in some cases, the maintenance of that behavior. The results of several detailed analyses of intra-session data and control experiments involving progressive ratio schedules of reinforcement help elucidate separate and distinct roles for these receptors in operant conditioning. Moreover, they suggest that behavioral neuroscience can be a fruitful ground for collaboration between behavior analysts and neuroscientists. |
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