Final answer:
A sample of brain tissue containing many large, highly-branched Purkinje cells indicates it came from the cerebellar cortex, due to these cells' unique presence in that region.
Step-by-step explanation:
The presence of many large, highly-branched Purkinje cells in a sample of brain tissue indicates that it came from the cerebellar cortex. Purkinje cells are a distinct type of neuron found in the cerebellar cortex and are known for their extensive dendritic arborization. They play a crucial role in motor coordination. The cerebellum itself is situated on the posterior surface of the brain stem, and it primarily connects to other parts of the brain through the pons, medulla, and midbrain via the cerebellar peduncles. Therefore, the presence of Purkinje cells directly points to the cerebellar cortex as their origin.