Rebound Bursts in Real Dopamine Neurons
Part 5 built a rebound burster out of an Izhikevich neuron and then left it sitting there as a piece of geometry. Fair question to ask next: what is the geometry for ? Stojanovic et al. (J Neurosci, 2025) give a clean answer. Rebound bursting isn't a party trick of thalamic relay cells. In the midbrain it looks like the mechanism that lets one specific population of dopamine neurons run fast. The question Dopamine neurons in substantia nigra are not one population. Split them by where they project and you get subpopulations with different molecular markers and different intrinsic physiology. Downstream, the dorsolateral striatum (DLS) shows the fastest dopamine transients of any striatal territory, fast enough that people have tied it to moment-to-moment vigor and variability in voluntary movement. Nobody had a mechanism for why DLS in particular gets the fast signal. The paper's answer is that DLS-projecting SN neurons carry a biophysical profile that lets them jump the...
