I suspect that no one is replying because they are not sure of Ohio law. I’m not a lawyer, nor do I play one on TV, but what I do know is that Ohio is not a gun friendly state. They have only in the past five years, adopted a concealed carry permit system after the Ohio supreme court ruled that the state was violating the state constitution by preventing individuals from carrying. While Ohio does recognize some carry permits from other states, Pennsylvania IS NOT one of them. If you do not have a permit from another state that IS recognized by Ohio, I would recommend that you keep the handgun and ammunition in separate containers, and ensure neither are accessible by the driver or passengers (i.e. locked in the trunk). Do not keep ammunition loaded in magazine(s), as I believe Ohio law considers this a loaded weapon.
As I indicated at the top, I am no expert on Ohio gun law, but these are the practices that are universally accepted for right of free passage, and the practices I have followed when traveling to / through Ohio. You might do better posting this in the Ohio forum, where people are more familiar with the laws of their state.
Regards,
Matthew