Behavioural reactions and changes in the spontaneous and evoked EEG-activity upon microinjection of noradrenaline and isoprenaline in cat nucleus raphe dorsalis.

Experiments are carried out on five cats with bipolar electrodes chronically implanted in various brain structures. The electrode intended to be introduced into raphe dorsalis is placed in a "guiding" isolated cannule. The spontaneous EEG-activity, the evoked potentials of photo- and electrostimulation as well as the behavioural reactions are studied for each animal before and after administration of noradrenaline (NA), isoprenaline (ISO) respectively, into nucleus raphe dorsalis (RD).

Background neuronal activity in cat somatosensory cortex before and after VPL damage. Histogram and taxonomic analysis.

Two groups of cats under barbiturate anaesthesia are used to study the effect of electrolytic coagulation in the VPL of the thalamus on the extracellular unit activity in the somatosensory cortex (the focus of maximum activity (FMA) of this part of the nucleus affected by the lesion). In the first group of animals a comparison is made between the unit activity before and immediately after coagulation, while in the second group of animals the activity of the neurones, recorded in FMA of the intact VPL is compared with that of the neurones in the homologous symmetrical point in the hemisphere, ipsilateral to the VPL coagulate 10-14 days before the acute experiment. The activity of 246 neurones is studied.

Participation of adrenergic mechanisms in the genesis of the cortical brain electrical activity.

The changes both in the spontaneous and in the evoked electrical activity of the somatosensory cortex, occurring after local or systematic administration of chlorpromazine, have been studied on 36 cats. The neuroleptic used weakens both the spontaneous cortical electrical activity and that induced by stimulation of n. radialis and of MRF.

[Comparative study of the changes in the EEG and cholinesterase activity in experimental Dipterex poisoning].

A systematic study is conducted on cats, poisoned with the organophosphorus insecticide Dipterex. The changes in spontaneous and induced cortical activity along with those in serum and erythrocyte cholinesterase after intraperitoneal and intramuscular injection of Dipterex are investigated. Against the background of lowered cholinesterase activity, recorded in all the experiments , the changes in EEG appear to be discrete and inconstant.