The acute slice preparation can be a powerful tool to study brain networks that would otherwise be difficult to manipulate at the synaptic and cellular levels. In the first part of this chapter, we discuss the specific challenges of preparing brain slices to study neural networks, and we review solutions to overcome problems that can be faced during slice preparation and maintenance. In addition, we describe slice preparations that preserve the connectivity between multiple brain areas, such as hippocampal and thalamocortical slices. In the second part, we introduce several techniques that can be used to stimulate specific cells or networks in acute slices. We begin by reviewing methods for electrical stimulation, glutamate-based stimulation, and optogenetic stimulation. An additional procedure that combines the use of laser photostimulation with flavoprotein autofluorescence is also presented. We discuss advantages and disadvantages of these methods for neural network investigation in the acute slice preparation.