Analysis of network changes in the kindling model of temporal lobe epilepsy

NASIMBERA, A. H; CORDISCO, S; SILVIA KOCHEN

Virtual

Congreso; Neuroscience 2021 - Society for Neuroscience; 2021

Society for Neuroscience

In this work we analyzed the firing rate (FR) of single neurons involved in the neuralnetwork during hippocampal rapid kindling (RK 3 days). Thirty male Wistar rats wereimplanted with a bipolar Macroelectrode (MacroE) for stimulation in the CA1 region ofthe right ventral hippocampus and also, eight Microelectrodes (MicroE) were implantedto record the electrical activity of the CA1 region of the right dorsal hippocampus. Twogroups were created out of the animals that successfully completed the procedure: TheRK group, consisting of 3 animals and the sham group with the remaining rat that wasimplanted but not stimulated. We proceeded according to the RK model stimulationparameters, and we analyzed the electrical signal. The analysis was performed in 57single neurons in total, 47 in the RK group and 10 in the sham group. The FR wasdetermined during the Basal (pre-stimulations) and After-Discharge (AD) periods. Theanalysis of the Basal and AD periods of kindled animals showed a progressive increasein the daily average of the FR along the protocol and a significant difference was foundbetween day 3 and day 1. We also found that data dispersion increased as thestimulations progressed. On the other hand, the qualitative analysis of the FR evidenceda possible classification of the neurons, with some of them increasing their FR during theAD period -the excitatory type (35%)-, some decreasing it -inhibitory type (32%)-, andsome not changing their FR at all, not directly involved in the epileptogenic network(33%). We demonstrated that the FR is strongly affected by the epileptogenic activityassociated with the RK. We believe these findings are relevant for a better understandingof kindling-associated network changes and might provide new targets for therapeuticstrategies in patients with epilepsy.