One reason scientists are so interested in inhalants is that these chemicals affect the body in lots of ways. While some effects are due to changes in the brain, others are direct actions on other parts of the body, such as the circulatory system.
Did you know that some inhalants directly increase the size of blood vessels, allowing more blood to flow through? And some inhalants can make the heart beat faster. This can be a serious problem, especially if someone inhales butane gas.