Directionality index of neural information flow as a measure of synaptic plasticity in chronic unpredictable stress rats

▶ Coupling direction index was significantly diverted in CUS. ▶ Strength of thalamus driving frontal cortex was considerably reduced in CUS. ▶ Chronic stress was decreased mPFC synaptic plasticity. ▶ Directionality index of information flow may be as a measure of synaptic plasticity. This investigation examined whether the directionality of neural information flow could be used to index the measurement of synaptic plasticity in the chronic unpredictable stress (CUS) animals. Evolution map approach (EMA) was employed to determine the direction of information flow between the cortex and thalamus, while the experiment was performed by inducing long-term potentiation of the thalamocortical pathway after recording intracranial EEG at the same two positions in Wistar rats of both normal and stressed groups. The results showed that the coupling direction index was significantly diverted in stressed state compared to that in normal state, while the strength of thalamus driving frontal cortex was considerably reduced in the rats of CUS model. Moreover, the data obtained from LTP experiment exhibited that chronic stress decreased medial prefrontal cortex (mPFC) synaptic plasticity, which was certainly in accordance with the EEG findings. These results demonstrated that using EMA measurement, directionality index of neural information flow may be as a measure of synaptic plasticity.