Dopamine Release Dynamics in the Tuberoinfundibular Dopamine System

• DOI: 10.1523/jneurosci.2339-18.2019
• Publication Date: 2019-02-19T22:55:29Z
• Authors: Stefanos Stagkour...; Johan Dunevall; Zahra Taleat; Andrew G. Ewing; Christian Broberger
• Keywords: Monoaminergic; Neurohormones; Neurochemical; Reuptake

The relationship between neuronal impulse activity and neurotransmitter release remains elusive. This issue is especially poorly understood in the neuroendocrine system, with its particular demands on periodically voluminous of neurohormones at interface axon terminals vasculature. A shortage techniques sufficient temporal resolution has hindered real-time monitoring secretion peptides that dominate among neurohormones. lactotropic axis provides an important exception neurochemical identity, however, as pituitary prolactin primarily under monoaminergic control, via tuberoinfundibular dopamine (TIDA) neurons projecting to median eminence (ME). Here, we combined electrical or optogenetic stimulation fast-scan cyclic voltammetry address dynamics male mouse TIDA system. Imposing different discharge frequencies during brief (3 s) ME revealed output maximal 10 Hz, which was found parallel neuron action potential frequency distribution phasic discharge. Over more sustained periods (150 s), occurred 5 similar average firing tonically active neurons. Application transporter blocker, methylphenidate, significantly increased levels ME, supporting a functional role neurons' terminals. Lastly, cell body yielded perisomatic dopamine, may contribute ultrafast negative feedback mechanism constrain activity. Together, these data shed light how spiking patterns system translate vesicular toward identify are controlled cellular compartments. SIGNIFICANCE STATEMENT central question neuroscience complex transmitter release. By combining voltammetry, this faces spatiotemporal exocytotic release; large amounts neurohormone need be secreted into portal capillaries precise timing adapt physiological requirements. Our show around default frequency. We further provide support for transport neurovascular terminals, shedding long-standing controversy about existence reuptake. Finally, occurs also somatodendritic level, providing substrate ultrashort autoregulatory loop.