Dopamine neurons of the ventral midbrain contribute to voluntary movement, the processing of natural rewards, and the etiology of several neurological disorders including Parkinson's disease, schizophrenia and drug addiction.  We use patch clamp electrophysiology of dopamine neurons to investigate both basic and applied questions concerning synaptic neurotransmission and cell excitability.

Regulation of dopaminergic synaptic transmission
While dopamine neurons are known to synapse onto each other in a dendro-dendritic manner, only recently has the first synaptic potential mediated directly by the neurotransmitter dopamine been identified (Beckstead et al., 2004).  This finding has enabled investigations concerning the pre- and post-synaptic regulation of dopamine transmission.  One major focus of the lab is to identify short- and long-term changes in synaptic strength ("plasticity") that are important for the behavioral consequences of dopamine cell activity.

Methamphetamine-induced changes in dopamine neuron activity
People who begin to abuse psychostimulants (such as methamphetamine) do so presumably for immediately pleasurable pharmacological effects.  However, repeated administration of many compounds produces wholesale physiological adaptations in cellular excitability and synaptic strength that can cause drugs to become addictive.  We use operant self-administration of methamphetamine in rodents to model human drug use and to investigate hypotheses concerning synaptic regulation of drug-related behaviors.  Determining the neurophysiological adaptations that occur with prolonged drug use is an important first step in identifying intervention strategies to better understand and possibly treat human drug abuse.