A Method for Training Rats to Electrical Self-Stimulation in Response to Raising the Head Using a Telemetry Apparatus to Record Extracellular Dopamine Levels

• Published in: Neuroscience and behavioral physiology 2024, Vol.54 (1), p.52-60
• Main Authors: Sizov, V. V., Lebedev, A. A., Pyurveev, S. S., Bychkov, E. R., Mukhin, V. N., Droblenkov, A. V., Shabanov, P. D.
• Format: Article
• Language: English
• Subjects: Behavioral Sciences; Biomedical and Life Sciences; Biomedicine; Dopamine; Electrical stimuli; Exploratory behavior; Head; Methods; Neurobiology; Neurosciences; Nucleus accumbens; Proprioception; Reinforcement; Self-stimulation; Telemetry; Ventral tegmentum
• ISSN: 0097-0549; 1573-899X
• DOI: 10.1007/s11055-024-01568-z

We present here a method for training rats to perform electrical self-stimulation in response to elevating the head using a telemetry device to record extracellular dopamine levels. Experiments reported by Olds were the first to show that the response to electrical stimulation of positive reinforcement zones in rats consists of natural exploratory behavior with the aim of seeking a source of reward. It has been suggested that a natural behavioral act, specifically raising the head, is able to accelerate the development and stabilization of the self-stimulation response. Changes in head position can serve as an internal proprioceptive conditioned signal. Experiments were carried out in an annular chamber, where the ventral tegmental area (VTA) was stimulated using a telemetry device when the rat’s head was raised to 38°. The self-stimulation response to headlifts developed and stabilized during the first day of training. For comparison, self-stimulation by pedal-pressing produced clear reproduction of responses only on training day 3 after the procedures of “pushing” the pedal on training day 1 and being “pushed off” the pedal on training day 2; stabilization of the response was observed only on training day 4. After stabilization of the self-stimulation response in rats, fast-scan cyclic voltammetry was used to record extracellular dopamine levels in the nucleus accumbens in response to externally defined stimulation of the VTA before and after each of three self-stimulation series lasting 10 min. Each series of self-stimulation was followed by decreases in the extracellular dopamine level, reflecting depletion of the intracellular dopamine pool during long-term self-stimulation of the VTA. These data lead to the conclusion that this method of teaching rats electrical self-stimulation in response to headlifts is promising for studying reinforcement mechanisms.