Which type of cells are considered insulin-independent?

Insulin-independent cells are those that do not require insulin for the uptake of glucose. Neurons are a prime example of such cells; they can absorb glucose directly from the bloodstream without the need for insulin. This characteristic is crucial because the brain relies on a continuous supply of glucose as its primary energy source.

In contrast, other cell types listed have different metabolic regulations. Hepatocytes do respond to insulin for glycogen synthesis and glucose uptake, making them insulin-dependent in this context. Proximal tubules of the kidneys have a unique role in glucose reabsorption that also involves different transport mechanisms, while the cells in the small intestine primarily deal with the absorption of nutrients rather than direct glucose uptake influenced by insulin. Thus, among the options provided, neurons are recognized specifically as insulin-independent cells, making this the correct choice.