|
| Recent Investigations in Tolerance and Sensitization to the Effects of Cocaine |
| Monday, May 30, 2005 |
| 9:00 AM–9:50 AM |
| Lake Ontario (8th floor) |
| Area: BPH |
| Chair: Jonathan W. Pinkston (University of Florida) |
| |
| Effects of Cocaine on Eating by Pigeons |
| Domain: Basic Research |
| JIN HO YOON (University of Florida), Marc N. Branch (University of Florida) |
| |
| Abstract: Effects of cocaine on feeding were examined when intermittent-food was presented for brief durations. In Experiment 1, pigeons were exposed to a variable-time 2-min schedule. Dose related decreases in eating were observed following acute administrations of cocaine. Following daily administrations of cocaine, tolerance was observed. In Experiment 2, 2 groups of pigeons were exposed to a 3-component multiple fixed-time schedule of reinforcement (i.e., 10 s, 30 s, & 120 s). The Before Group received cocaine immediately prior to session and saline following session. The After Group had the order of their injections reversed. Once dose-response functions were assessed, the order of injections was reversed so that all subjects eventually had experience receiving cocaine before and after session. Overall, the degree of tolerance observed was similar across components for a given subject. Additionally, tolerance was more likely to be observed when cocaine was administered prior to session and sensitization was more likely to be observed when cocaine was administered following session. Both Experiment 1 and 2 concluded with the assessment of dose-response functions in the context of daily saline administrations. Under these conditions, dose-response functions generally shifted to the left. |
| |
| Effects of Cocaine on the Locomotor Behavior of Pigeons |
| Domain: Basic Research |
| JONATHAN W. PINKSTON (University of Florida), Marc N. Branch (University of Florida) |
| |
| Abstract: Previous research has shown that intermittent administration of cocaine may result in increased sensitivity of locomotor behavior to the drug, a phenomenon known as sensitization. Recent work in our lab has been focused on documenting these changes in the drug’s effects using pigeons. In the present experiment, we examined the ability of various doses of cocaine to produce sensitization. This provided us with an opportunity to validate a device designed to detect locomotor behavior in birds. We also examined cocaine’s effects on other behaviors, e.g. grooming, during the development of sensitization. Pigeons were exposed to daily administration of 1.0, 3.0, or 10.0 mg/kg cocaine, across groups. The results showed increased sensitivity to the drug developed to the locomotor behavior of all subjects, regardless of daily dose. Higher daily doses of cocaine resulted in increased sensitivity to higher doses of cocaine than did lower daily doses. Furthermore, the results showed a change in maximum effect in addition to the increase in sensitivity. These effects in relation to the various other behaviors measured will be discussed |
| |
|
| |