Behavioural and electroencephalographic effects of intracerebral microinjections of sodium pentobarbital

The effects of intracerebral microinjections of Nembutal into different brain areas, with the purpose of reproducing the behavioural and EEG signs of barbiturate narcosis, have been studied and analyzed. Cats were implanted for polygraphic study of the sleep-wakefulness cycle and bilateral brain canulae were also placed in strategic brain areas. The most striking results was the controlateral turning after unilateral injections of Nembutal in the nigra, suggesting a loss of balance among the actions of the nigro-striatal-cortical pathways on both sides. The sequence of events produced by intravestibular injections of Nembutal suggests that the drug, when injected intraperitoneally, acts also upon the vestibular system. This data stresses the importance of localized intracerebral microinjections of drugs to determine and differentiate their action mechanisms when injected in an intraperitoneal or intravenous way.