EFFECT OF CHRONIC LITHIUM TREATMENT WITH OR WITHOUT HALOPERIDOL ON NUMBER AND SIZES OF NEURONS IN RAT NEOCORTEX

The present study used stereological methods to determine whether long -term administration of lithium, with or without haloperidol, affects the number and average volume of neocortical neurons. Twenty-five rats were divided into three groups and given no treatment, lithium, or li thium combined with haloperidol. Serum lithium levels ranged from 0.5 to 0.8 mmol/l. Haloperidol was injected intraperitoneally at a daily d ose of 1 mg/kg. After 30 weeks of treatment, the animals were killed a nd the brains were prepared. Neocortical volume, density of neurons, t otal number of neurons and mean volume of neurons were estimated. As n o differences were found between the groups, the present study provide s no evidence for quantitative morphological changes in the cerebral c ortex due to long-term 'therapeutic' levels of lithium, with or withou t haloperidol.