Behavioral assessment of atypical antipsychotics in rats: studies of the effects of olanzapine (Zyprexa)

Abstract

On tests of jaw-movement activity and lever pressing after both acute and repeated drug administration, olanzapine demonstrated a profile somewhat similar to clozapine, and both of these drugs differ substantially from the typical antipsychotic haloperidol.

Quetiapine (Seroquel) shows a pattern of behavioral effects similar to the atypical antipsychotics clozapine and olanzapine: studies with tremulous jaw movements in rats

“…This finding is consistent with previous studies showing that cholinomimetic-induced tremulous jaw movements can be suppressed by other atypical antipsychotic drugs, including the prototypical compound clozapine (Stewart et al 1988;Chesler and Salamone 1996;Trevitt et al 1999) and the more recently developed drug olanzapine . As was the case with previous studies of clozapine and olanzapine (Trevitt et al 1997, quetiapine was also assessed for its ability to suppress lever pressing.…”

“…Results from other typical and atypical antipsychotics also are shown. Behavioral data for additional drugs are from Trevitt et al 1997Trevitt et al , 1999Salamone et al 1998. Pimozide data are unpublished (Ishiwari et al 2005 work has shown that olanzapine and clozapine, like quetiapine, all have ED 50 ratios lower than 1.0, while the typical antipsychotics haloperidol and pimozide fail to suppress jaw movements, even at doses 3-11 times higher than the dose that suppresses lever pressing (Trevitt et al 1997Ishiwari et al 2005).…”

“…Although several studies have shown that acute or subchronic administration of typical antipsychotics induces tremulous jaw movements, it has generally been reported that atypical antipsychotics such as clozapine, olanzapine and risperidone are less robust in producing this effect, or fail to do so altogether (Steinpreis et al 1997;Trevitt et al 1998Trevitt et al , 1999Marchese et al 2002Marchese et al , 2004. In fact, clozapine actually suppressed cholinomimetic-induced jaw movements (Chesler and Salamone 1996;Trevitt et al 1997) and did so in doses that were lower than those required for suppression of lever pressing (Trevitt et al 1997.…”

Multidose Risperidone Treatment Evaluated in a Rodent Model of Tardive Dyskinesia

“…Moreover, the movement quality in these animals was jerky and irregular, not a regular tremor. We and others (Gunne et al, 1982;Ikeda et al, 1999;Tamminga et al, 1990;Trevitt et al, 1999) have argued for a connection between these VCMs and TD, and have suggested and tested a systems pathophysiology distinct from parkinsonism to account for the movements (Shirakawa and Tamminga, 1994;Sakai et al, 2001).…”

Effects of olanzapine infusions to the ventral tegmental area on lordosis and midbrain 3?,5?-THP concentrations in rats

“…Olanzapine also seems to reduce anxiety and improve functioning of people with post-traumatic stress disorder (Petty et al 2001), Alzheimer's disease (Mintzer et al 2001), Huntington's disease (Squitieri et al 2001), or autism (Santosh and Baird 2001). Unlike typical antipsychotics, olanzapine's therapeutic effects occur with negligible extrapyramidal side effects and akathesia (Stanford and Fowler 1997;Steinpreis et al 1999;Trevitt et al 1999). Thus, olanzapine is a very useful drug.…”