Electrical stimulation of the brain tissue  has been already accepted as the valuable method of supporting  correctness of the activities  of the stimulated neuronal networks.  However, there are still uncertainties concerning possible consequences of stimulation expressed in early, as well as delayed effects of stimulation,  and of course the safety of the brain tissue – depending on the intensity of stimulating currents. Results of the direct electrical stimulation performed  in experimental model of epilepsy in animals (kindling)  illustrated dependence of the received results on the localization of the stimulated structure. E.g., comparing the results of the direct electrical stimulation of the structures of the temporal lobe and  of the  neocortical structures. The informations received during experiments  in kindling model of epileptogenesis in cats clearly illustrated differences between the effects  of electrical stimulation of these structures-  e.g. variability of the effects of stimulation of the neocortical structure . Understanding the background of such differences  requires availability  of the realistic model of  the structure and function of the stimulated cellular network . The study of the neocortical activity in the animal with permanently implanted multichannel electrodes enabling recording the EEG patterns as well as patterns of the cellular activity in normal conditions ( during wakefulness and sleep) clearly illustrates  complexity of the functional organization of the cortical tissue (1). Such study in conditions of the experimental models of epilepsy in animals without electrical stimulation of the cortical tissue  (e.g. ionic or  penicillin  model of epilepsy) clearly illustrates existence of the phenomenon  of the “biological kindling” : existence of the definite patterns of the activity of neocortical structure participating in the process  leading inevitably to the appearance of the “clinical” epileptic seizures. Such study illustrated also probability of existence of the cellular network in the neocortical tissue participating in transition of the EEG  pattern of Slow Wave Sleep to the EEG pattern characterizing REM sleep (with suppression of the slow waves). Activity of such a network, with the basic frequency of activity within the gamma  frequency waves may be also observed in association with the presence of the appearance of high amplitude discharges of sharp waves, spikes and slow waves on definite stages of epileptic reorganization of cortical activity. These findings appear to correspond to the results of analysis of EEG patterns in EEG records of the persons with epilepsy, after  transcranial magnetic stimulation, illustrating reorganization of the pattern of cortical activity  with respect to the prestimulation period :  with evidently affected  appearance of the synchronized  low frequency slow waves and sharp waves and spikes after stimulation (2).  

    

1. Sobieszek, A.

 Cellular and EEG Patterns of the Reorganization of Cortical Activity in Animal Experimental Models of Epilepsy (in Cats).

     In: Epilepsy During the Lifespan -  Beyond the Diagnosis and New   

     Perspectives.

Edited by Marco Carotenuto

IntechOpen, London, United Kingdom,  2024, pp. 3 – 15.

2. Olejarczyk,  E.; Sobieszek, A.; and Assenza, G.

Automatic Detection of the EEG Spike-Wave Patterns In Epilepsy: Evaluation of the Effects of Transcranial Current Stimulation Therapy. 

Int. J. Mol. Sci. 2024, 25, 9122.

https:/ /doi. org/ /10.3390/ ijms 251 691 22