The present disclosure is directed to compositions and methods which utilize the tetracycline scaffold, preferably the scaffold of tetracycline or minocycline, and which significantly lack antibiotic activity. The compounds have neuroprotective attributes without interfering with the drugs capacity to pass through the blood brain barrier. These compounds have neuroprotective activity because of their inhibition of neuronal cell cycle progression. The compounds are characterized in part by a fifth ring joining positions 9 and 10.