Consciousness is a function whose input is environmental stimulus and whose output is a cyclical thought, and/or a physical action (muscle contraction). The more environmental-semantic information this entity encodes in its memory, the more “conscious” it is, but consciousness is not binary.

Logic gates form if:then statements that, when assembled together, creates a system of behavior that acts in somewhat logical ways. Human biological neuron cells form these.

Consciousness inherently requires at least some memory, input, and processing. Every neuron in the human brain is technically computable because it’s just input and output of electrical signals.

A nerve cell is effectively just an analog neuron with a few extra properties. It’s not logical to assume that consciousness is just a bundle of nerve cells. It’s a very architecturally-dependent bundle of if/then clauses and memory that, when combined, simulates consciousness.

If a system can be described by if/then, then it is computable.

Also, if you cut a living brain in half, it ceases to become conscious. The reason for this is that the architecture becomes incoherent. When you are asleep (beasides REM/dreaming) you are also unconscious.

Regardless, all my points to say: consciousness is computable through architecture, not simply through nerve cells. Biological human nerve cells are neither necessary nor sufficient for consciousness.