Desynchronous (low voltage fast activity), synchronous (high voltage slow waves) as well as convulsive brain activities were simulated by a computer model of neuronal population. Network excitatory and inhibitory elements possessed fundamental dynamic properties of real neurons. Being independent both of the excitability of elements and of external influence efficacy, synchronous (desynchronous) network activity resulted from the increase (decrease) of the average power of «neuronal» interconnections which imitated mutual and recurrent excitation and inhibition. The inhibition efficacy being reduced as compared with excitation, synchronization of elements became intensified. As a consequence, the rhythmic activity amplitude increased and the appearance of self-sustained oscilla-tions simulating convulsive activity was facilitated. The probable mechanism of EEG activation by virtue of the reduction of mutual and recurrent excitation and inhibition efficacy as well as the significance of inhibitory mechanism deficiency for epileptogenesis are discussed.
Calculation on a mathematical model showed that for undistorted conduction of excitation through a net of excitatory elements (EEs) a system is necessary of optimum correlation of EEs parameters, links between them and of external influences. When these parameters are deviated from their optimum values, excitation is conducted through the net either with attenuation or with intensification (as a result of divergence and conver- gence of the influences of the previous layer on the following one). The background activity which is above threshold of impulse activity emergence and which is created by common effects on all EEs, prevents the revealing of the input EEs activation at the net output. Nearthreshold tonic net activation facilitates excitation conduction through it. Periodic net activity facilitates excitation conduction through it only under optimum correlation of its parameters and the time of its conduction through the net. At disturbance of this condition, excitation conduction through the net is limited.
In experiments on training of the model for ensuring reliability in recognition and classification of images need of use of three types of inhibition is found: preexciting inhibition, dominant inhibition and inhibition, organizing work of «an acceptor of result of action». The possibility of generalization of the images, similar and dissimilar, was realized by introduction to network of the additional block. During training one of its elements is in a condition of activation every time when on an entrance the image belonging to a certain class moves. Generalization happens by the principle of coincidence in time.
CHAPTER VI
APPLIED RELEVANCE OF KNOWLEDGE OF NEUROPHYSIOLOGY OF INHIBITION OF BEHAVIOUR
Excitement, inhibition and genetics.
Inhibition and frontal departments of a brain.
GABA and depression.
Post-traumatic stressful frustration (PTSR).
The neurophysiological explanation of epidemic of a suicide during the period is social – an economic crisis.