ANALYSIS OF SINGLE-UNIT ACTIVITY AND LOCAL FIELD POTENTIALS DURING THE PROGRESSION OF EPILEPTOGENESIS ON AN EXPERIMENTAL EPILEPSY MODEL

BELEN GORI ; MARTÍN TIBALDI; SANTIAGO COLLAVINI; FERNANDO CHAURE; JUAN CONVEY; GERARDO BATTAGLIA; IGNACIO CERDA CASTRO; MICAELA SANZO; LAUTARO LEDESMA; SILVIA KOCHEN

Mar del Plata, Buenos Aires

Congreso; XXXII congreso anual SAN 2017; 2017

Sociedad Argentina de Investigación en Neurociencias

Epileptic seizures are sudden changes in neural activity that interfere with the normal functioning of the neural network, expressed through hypersynchronic discharges. The aim of this study is to analyze how single-unit activity (SUA) and local field potentials (LFP) would be affected during the progression of epileptogenesis. Male Wistar rats were implanted with a bipolar macroelectrode in the CA1 region of right ventral hippocampus, through which they were kindled, and eight microwires were placed in the CA1 region of right dorsal hippocampus (rdH). SUA and LFP were recorded continuously during the rapid kindling protocol. SUA and LFP ictal and interictal activity of rdH were analyzed.We found heterogeneous changes in neuronal firing rate during electrographic seizure activity. Different patterns of neuronal activity were observed. Some neurons increase and others decrease their firing rates, while many units did not change. The interictal firing rate becomes higher according as epileptogenesis progresses.These different degrees of stereotypical firing patterns during seizures might depend on whether or not neurons are actually being recruited by the propagating wave of seizure spread. The combined study of SUA and LFP can provide new insights into the process of transition to seizure, allowing us to assess precisely the dynamic changes involved in epileptogenesis. Future studies are needed to understand how these patterns would be involved in epileptogenic networks.