Background: Maternal deprivation (MD) in early ontogenesis causes persistent changes in emotional reactions and drug abuse in animals. In the present study, we modeled an addictive state of excitement and risk of a dopamine nature that underlies the formation of gambling behavior disorder. The aim of the study: To study the dopamine mechanisms of the addictive state in rats after MD by analyzing the release of dopamine in nucleus accumbens in response to electrical stimulation of the self-stimulation zone of the ventral tegmental area (VTA) in a reinforcement model close to the situation of excitement and risk of gambling. Materials and methods: Rats from the 2nd to the 12th day of the postnatal period were placed in individual containers for 180 min for 10 consecutive days. In adult rats, electrodes were implanted in the VTA and nucleus accumbens. The animals were trained to respond to VTA self-stimulation in a fixed ratio FR3 in a Skinner box with a smooth floor, translucent walls, and with a stimulus light when the pedal was pressed. Dopamine release was recorded in the nucleus accumbens using fast-scan cyclic voltammetry in response to stimulus light and simultaneous stimulation of the VTA in the Skinner box between self-stimulation series. The animals were also trained to respond to self-stimulation in the VR6 variable ratio and tested in a Skinner box with a grid floor, white walls and with a stimulus tone when the pedal was pressed. Dopamine release was recorded in a similar manner. Results: In control rats, the level of extracellular dopamine in response to stimulation of the VTA with a stimulus light or tone conditioned signals in the Skinner box increased, but statistical analysis did not show significant differences when using the FR3 ratio and VR6 ratio. In MD rats, extracellular dopamine levels increased to a greater extent in response to VTA stimulation when a conditioned signal was presented in the Skinner box when using the VR6 retio compared to the FR3 retio. Conclusion: Thus, the stress of maternal deprivation in early ontogenesis causes an increase in the release of dopamine in nucleus accumbens in response to stimulation of the VTA positive reinforcement zone, which is accompanied by the supply of a conditioned signal of an addictive state of self-stimulation in a variable ratio, close to the situation of excitement and risk
Background: Maternal deprivation (MD) in early ontogenesis causes persistent changes in emotional reactions and drug abuse in animals. In the present study, we modeled an addictive state of excitement and risk of a dopamine nature that underlies the formation of gambling behavior disorder. The aim of the study: To study the dopamine mechanisms of the addictive state in rats after MD by analyzing the release of dopamine in nucleus accumbens in response to electrical stimulation of the self-stimulation zone of the ventral tegmental area (VTA) in a reinforcement model close to the situation of excitement and risk of gambling. Materials and methods: Rats from the 2nd to the 12th day of the postnatal period were placed in individual containers for 180 min for 10 consecutive days. In adult rats, electrodes were implanted in the VTA and nucleus accumbens. The animals were trained to respond to VTA self-stimulation in a fixed ratio FR3 in a Skinner box with a smooth floor, translucent walls, and with a stimulus light when the pedal was pressed. Dopamine release was recorded in the nucleus accumbens using fast-scan cyclic voltammetry in response to stimulus light and simultaneous stimulation of the VTA in the Skinner box between self-stimulation series. The animals were also trained to respond to self-stimulation in the VR6 variable ratio and tested in a Skinner box with a grid floor, white walls and with a stimulus tone when the pedal was pressed. Dopamine release was recorded in a similar manner. Results: In control rats, the level of extracellular dopamine in response to stimulation of the VTA with a stimulus light or tone conditioned signals in the Skinner box increased, but statistical analysis did not show significant differences when using the FR3 ratio and VR6 ratio. In MD rats, extracellular dopamine levels increased to a greater extent in response to VTA stimulation when a conditioned signal was presented in the Skinner box when using the VR6 retio compared to the FR3 retio. Conclusion: Thus, the stress of maternal deprivation in early ontogenesis causes an increase in the release of dopamine in nucleus accumbens in response to stimulation of the VTA positive reinforcement zone, which is accompanied by the supply of a conditioned signal of an addictive state of self-stimulation in a variable ratio, close to the situation of excitement and risk