Central and peripheral effects of lithium on conditioned taste aversions in rats

Central and peripheral injections of LiCl were given to rats to see whether conditioned taste aversions are caused by central or peripheral effects of Li. Rats received an IP injection of either 150 mmol/l LiCl or 150 mmol/l NaCl and a bilateral intracerebroventricular (ICV) injection of either 150 mmol/l LiCl, 150 mmol/l NaCl, or artificial cerebrospinal fluid (CSF) after drinking saccharin solution. Subsequent saccharin intake decreased in rats which received the IP LiCl injection, but failed to depend on which ICV injection had been given. The concentration of Li in bain and CSF was higher 0.5, 1.5, and 4 h after the ICV LiCl injection than after the IP LiCl injection, while the reverse was true for the plasma Li level. It is concluded that conditioned taste aversions are mediated by peripheral effects of Li.