Hydrogen Peroxide as a Diffusible Messenger: Evidence from Voltammetric Studies of Dopamine Release in Brain Slices

Excerpt

In this chapter, we will discuss various methodological considerations for the use of in vitro voltammetric recording in brain slices, which will indicate the types of questions that these methods are best suited to address. In addition, we will review evidence that H₂O₂ is a diffusible messenger that mediates glutamate-dependent inhibition of DA release in dorsolateral striatum, based on data obtained using fast-scan cyclic voltammetry (FCV) with carbon-fiber microelectrodes in brain slices [9,10]. These studies also indicate the mechanism of release suppression, which is the activation of ATP-sensitive potassium (K_ATP) channels. Companion electrophysiological studies show that H₂O₂ also regulates the spontaneous activity of DA neurons in the substantia nigra pars compacta (SNc) via K_ATP channels [11], consistent with the apparently abundant expression of these channels throughout the nigrostriatal pathway [12–14]. Together, these studies illustrate how voltammetric methods in brain slices, both alone and in combination with companion techniques, can be used to address important questions in neuroscience.