VTA GABAergic plasticity: An inhibitory synaptic model of drug addiction

There is now compelling evidence suggesting that addiction is a pathological form of habit-based learning of the brain that involves drug-induced synaptic plasticity in addiction-related areas of the brain including the ventral tegmental area (VTA). Fortunately, over the last decade, tremendous progress has been made in the identification of neuroplastic changes in the relevant neural circuits involved in the development and maintenance of addiction using synaptic plasticity models. The current model of addiction supports the idea that the VTA is the major starting point of addiction-associated plasticity of the brain in response to drugs of abuse. While synaptic plasticity at excitatory synapses is well-studied and is correlated with addiction, the role of synaptic plasticity at inhibitory synapses is less well understood. However now there is a growing interest in characterizing and uncovering the underlying mechanisms of these forms of inhibitory plasticity and their link to different aspects of brain function, including the development of addictive behaviors. In this chapter, I will provide a brief synopsis of some forms of synaptic plasticity associated with addiction found at inhibitory GABAergic synapses in the VTA.