Detection of epileptic activity is usually based on analysis of brain electromagnetic signals, including Eggs, MEGs, local field potentials and single/multi neuron unit recordings. Pentylenetetrazol is traditionally used to provoke epileptic seizures in healthy animals: rats, mice and guinea pigs. Such pharmacological models of epilepsy allow us to study the work of deep brain structures, including the thalamus and hippocampus, actively involved in the development of pathological activity. The pathological activity in epilepsy is considered to detect in all involved brain areas. However, in some animal models this was not tested properly. Recently we found that in pentylenetetrazol rat model of absentee epilepsy in half of subjects significant part of discharges are expressed only in one hemisphere. So that we decided to assessment of connectivity between brain hemispheres for this epilepsy form. For that we used some methods such as calculating the values of the estimating mutual information and phase coherence index.