Scientists use squid nerve cells in research because the nerve cells of a squid are 1,000 times fatter than those of a human. how is the outcome of nerve cell research most likely to be affected if scientists were to study human nerve cells directly?

May get a better understanding or may not be able to explore the nerve cell due to its small size as compared to squid nerve cells/axon

Explanation:

Biologist and scientist are aware of the fact that each and every nerve cell is essential for proper molecular functioning of body. The sodium/potassium pump is essentially important for all the cells and hence it is considered by biologist to take out human nerve cell and conduct research on it. Thus they prefer using squid nerve cell.  

Also scientists prefer to use squid axons because they are exceptionally large (with 1 mm width and length of even 1 meter) due to which it is easy to study their counter parts. Their manipulation for research work is also easy and hence all basic researched till date have helped scientist to develop a better understanding electrical signal and henceforth the driven system.