The Spencer lab has a broad interest in studying mechanisms related to the development of addiction as well as relapse in the late stages of the disease. They also want to better understand risk factors and psychiatric comorbidities associated with drug addiction. They are currently pursuing studies in two general broad project areas:
- Examination of dopamine and glutamate interactions duirng cue-induced cocaine seeking and taking. Cue-induced transient synaptic plasticity (t-SP) at glutamatergic synapses on nucleus accumbens core medium spiny neurons occurs within 15 minutes and disappears within 2 hours. These researchers have shown that cocaine taking after initiating cue-induced reinstatement rapidly reverses cue-induced transient synaptic plasticity in the accumbens, and demonstrates just how dynamic these neuroadaptations are within a modified 2-hour reinstatement session. These results support a correlation between t-SP and motivated lever pressing and raises the possibility that cocaine-induced increases in extracellular dopamine may suppress t-SP.
- Understanding distinct and overlapping neural circuits encoding the rewarding versus the aversive properties of cannabinoids. Tetrahydrocannabinol (THC) is the most widely used illicit drug worldwide, but enduring consequences of its use, especially in terms of neurobiology, are largely unknown. The drug displays a narrow dose reward window, but produces enduring neuroadaptations following chronic self-administration that resemble other drugs of abuse. Understanding how both reward and aversion are encoded with use of this drug will help guide development of therapeutics for treating cannabis use disorder as well as designing non-addictive cannabinergic therapies for disorders like chronic pain.