Watch this webinar to learn how combining two-photon calcium imaging with simultaneous optogenetic activation, and patch-clamp in brain slices can reveal the nuances of dendrite-specific and subpopulation-specific inhibitory control of dopamine neurons.
Dopamine neurons are embedded in a predominately inhibitory network. Because dopamine neurons are tonically active, both excitatory bursts and inhibitory pauses in their firing can transmit meaningful information. In this talk, I will address how these bursts and pauses in activity interact with each other through the recruitment of specific intrinsic and synaptic currents. I will show that two populations of substantia nigra dopamine neurons, defined by their differential vulnerability to neurodegeneration in Parkinson’s Disease, differ in their dendritic calcium signaling and their ability to recover from periods of inhibition. I use dendrite-specific optogenetic activation and two-photon calcium imaging to functionally map the location of inhibitory synaptic inputs onto dopamine neuron dendrites and use whole-cell patch clamp and computational modeling to show how distinct inhibitory sources differentially modulate dopamine neuron activity. Overall, I describe a striking heterogeneity in the cellular and circuit level control of dopaminergic signals.
Rebekah Evans Ph.D., Georgetown University