Motivational Effects of Methamphetamine as Measured by the Runway Method Using Priming Stimulation of Intracranial Self-stimulation Behavior

Abstract

Priming stimulation is known to promote the motivational effects of intracranial self-stimulation (ICSS) behavior. The runway method using priming stimulation can experimentally distinguish the reward and motivational effects of ICSS behavior. In this study, we examined the motivational effect of a drug as determined by the runway method using priming stimulation of ICSS behavior. Electrodes were implanted chronically into the medial forebrain bundle (MFB) of the rats. A lever for stimulation of the MFB was set on the opposite side of the start box in the apparatus. The rats were trained to obtain a reward stimulation (50-200 m mA, 0.2 ms, 60 Hz) of the MFB by pressing the goal lever, and then priming stimulation of the MFB was applied. After priming stimulation, rats were placed in the start box of the runway apparatus and the time taken by the rat to press the lever was recorded. Priming stimulation frequency was significantly correlated with running speed (r‫,798.0؍‬ pϽ0.05). Methamphetamine (1, 3 mg/kg) induced an increase in running speed (F(3, ‫,752.61؍)02‬ pϽ0.01), and was further increased with increase in priming stimulation frequency. In addition, methamphetamine significantly enhanced the motivational effect. These results suggest that the runway method using priming stimulation of ICSS behavior may be an effective way to evaluate the enhancing effect of a drug on motivation.

Nicotinic Acetylcholine α4β2 Receptor Regulates the Motivational Effect of Intracranial Self Stimulation Behavior in the Runway Method

“…It was reported previously that nicotine induced a significant increase in running speed (18). This study confirmed that nicotine (0.2 mg / kg) significantly enhanced the motivational effect on ICSS behavior using the runway method.…”

“…In this study, drug efficacy was evaluated using a method comparing the running speed of the control and drug sessions with five priming stimulations. The running speed of five priming stimulations was able to confirm the increase / decrease in drug efficacy (15,18). Thus, the drug efficacy of nicotine and nAChR antagonists was tested with this experimental setup.…”

“…Therefore, the runway method has priorities in this respect compared with the method of experimenting on CPP and intracranial self-administration. Furthermore, nicotine was reported to significantly enhance the motivational effect in ICSS with the runway method (18). However, the influence of the nAChR subtype on the motivational effect of nicotine is unclear.…”

Effect of GBR12909 on affective behavior: Distinguishing motivational behavior from antidepressant-like and addiction-like behavior using the runway model of intracranial self-stimulation

“…Since ICSS 3 measures have been proposed as experimental models for evaluating altered interest or pleasure/hedonia, ICSS has been recognized as a valid measure of motivational state [12]. Indeed, our previous studies demonstrated that both nicotine and methamphetamine enhanced motivated behavior as observed in the runway model of ICSS [13][14][15]. However, it is not clear whether these behavioral alterations reflect a motivational enhancement for receiving ICSS reward or a reinforcing effect of these addictive drugs.…”

A New Method for Evaluation of Motivational Effects of Drugs

“…Administration of 1 and 3 mg/kg of methamphetamine increases running speed (11). Motivational and rewarding effects are indispensable for completion of target-oriented behavior, and such complex behavior is not simply regulated by locomotor activity.…”