T-type calcium channels are strongly associated with the generation of rhythmic 
firing patterns in the CNS. Blockers of these channels may have therapeutic 
potential for treating various types of tremor. The present study aimed to study 
the effects of a range of T-type calcium channel blockers in a parkinsonian 
tremor model in rats. We tested the effects of several T-type calcium channel 
blockers, including zonisamide (ZNS), ethosuximide, lomerizine, amiloride, 
mibefradil, and NCC 55-0396, a mibefradil derivative, on tacrine-induced 
tremulous jaw movements (TJMs), an animal model of parkinsonian tremor. Among 
the tested drugs, only ZNS and NCC 55-0396 significantly suppressed TJMs when 
given at a non-sedating dose. The transitivity of drugs to the central nervous 
system (CNS) may at least partially explain their differential anti-TJM effects. 
However, further studies are necessary to reveal other factors, since 
ethosuximide failed to show anti-TJM effects despite being known to cross the 
blood brain barrier. The present results suggest that T-type calcium channels in 
the CNS may be a suitable target for developing new therapeutic strategies for 
treating parkinsonian tremor.