Neurophysiological mechanisms of formation of non-chemical dependence through self-stimulation of positive emotiogenic areas of rats’ brains

Abstract

The aim of our research was to study the limbic-neocortical mechanisms of addictive behaviour in rats formed throughthe arousal of intense emotions on the model of self-stimulation reaction of the brain. We carried out investigations by conducting a chronic experiment on 15 nonlinear laboratory male rats weighing 250 to 320 grams, at the ages of 5 to 6 months. As a model of receiving positive emotions we used the behaviour of animals held in a Skinner box which was formed through self stimulation of the positive emotional zones of the posterior ventrolateral hypothalamus. We registered the frequency of self-stimulation reactions of the ventrolateral hypothalamus daily for 4 days and on the 7th day after its ccessation (state of deprivation). We performed visual and spectral analysis of the electrical activity of the brain using "Neuron-spektr.net" software. We assessed the absolute spectral density of the power of rhythm signals of the following frequency bands: delta (0.5–4.0 Hz), theta (4.0–7.0 Hz), alpha (8.0–12.0 Hz) and low frequency beta (14.0–20.0 Hz). The formation of behaviour dependent on receiving intense emotions as a result of self-stimulation of the positive zones of the ventrolateral hypothalamus is caused by the initial high level of need for positive emotional reinforcement and further growth in the implementation of desire and is associated with activation of emotional memory mechanisms, changes in electrogenesis in the hippocampus and the reticular formation in the form of decrease in the spectral power of rhythms of alpha and beta bands and increased spectral power of biopotentials of the delta range in the hippocampus and theta range in the reticular formation with severe manifestations of seizure and paroxysmal activity components and increased activity of the sympatho-adrenal system. The syndrome of withdrawal fromthe receiving of positive emotions in some rats with implementation of a programme of a phobic character with an increase in beta rhythms in all thestudied structures, and among other rats with implementation of a programme of an aggressive character, which was characterized by increased electrical seizure activity in the hippocampus, is caused by oppression of electrogenesis in the hypothalmus and replacement of slow wave activity in the reticular formation at high frequency rhythms in the alpha-theta range.

Keywords

• biopotentials
• posterior ventrolateral hypothalamus
• positive emotion
• aggressive behaviour
• anxious behaviour