EN
The psychogenetically selected Roman High (RHA/Verh) and Roman Low (RLA/Verh) Avoidance rats constitute a widely accepted model of diverse emotional reactivity. They show divergent stressrelated behavioral and neuronal responses when confronted with a novel and/or stressogenic environment (Meyza et al. 2009). Here, we have explored the possibility that the difference might be also refl ected in the electrical activity of prefrontal cortex (mPFC), amygdala (Amy) and hippocampus (CA1) – structures involved in generation of emotions. Spectral analysis of telemetrically recorded local fi eld potentials (LFPs) from mPFC, Amy and CA1 in freely moving rats performing behavioral tests differing with aversiveness (Open Field, Elevated Plus Maze, Hole Board test and Acute Restraint) showed that power of 4 distinct frequency bands (delta: 0–3 Hz, theta: 4–12 Hz, beta: 13–30 Hz and gamma: 31–90 Hz) is higher in the LFPs of RLA/Verh than of RHA/Verh rats, especially in the CA1 and mPFC. This difference seems to be stress-dependent (among tests measuring spontaneous behavior). Acute restraint elicited differences only in the delta and gamma bands in the mPFC. Strikingly, the difference is most clear while the animal is performing a decisive/risk assesment behavior (e.g. leaning towards aversive part of the arena). Moreover, individual differences in the power of bands can be observed at that time, thus they may be considered a neuronal correlate of individual differences in emotional reactivity.