Protocol

Imaging Zinc in Brain Slices

This protocol was adapted from "A Practical Guide: Imaging Zinc in Brain Slices," Chapter 63, in Imaging in Neuroscience and Development (eds. Yuste and Konnerth). Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, USA, 2005.

INTRODUCTION

This protocol provides a practical guide to imaging zinc within synaptic vesicles and the extracellular space of brain slices. Certain glutamatergic synaptic terminals in the brain have high concentrations of exchangeable Zn²⁺ within their synaptic vesicles. Classically, these terminals have been revealed by Timm’s histochemical stain. More recently, a number of fluorimetric probes have become available that allow Zn²⁺ to be detected in live preparations. This protocol describes two methods, one for visualizing Zn²⁺ in synaptic vesicles, and another for detecting Zn²⁺ in the extracellular space. These methods are applicable to any tissue with the high levels of loosely bound Zn²⁺ that are typically found in vesicles, and tissue that might have Zn²⁺ associated with macromolecules in the extracellular space.