Deep Brain Stimulation Modulates Nucleus Accumbens Theta-Band Power in a Rodent Model of Schizophrenia

Deep brain stimulation has proven a powerful treatment option for various neuropsychiatric diseases. In psychiatry, this is particularly relevant for schizophrenia, where up to one third of patients do not respond to current treatment options. To further understand the possible mechanisms of deep brain stimulation for schizophrenia, this study combined deep brain stimulation with electrophysiological recordings.

Injections of polyriboinosinic/polyribocytidilic acid were administered during pregnancy to induce a well-established maternal immune activation model of schizophrenia. Seven model offspring animals and nine control male Wistar rats underwent a high-frequency deep brain stimulation protocol. Electrophysiological recordings in the medial prefrontal cortex, the nucleus accumbens, the ventral hippocampus and the ventral tegmental area were performed before and after stimulation.

Maternal immune activation caused overall changes in local field potentials in the prefrontal cortex and neuronal spiking in the ventral hippocampus. In all recorded regions a transient effect of stimulation with increased spikes and bursts was visible. However, only in the nucleus accumbens was an effect following stimulation visible. Here, a significant group difference in theta-band power was seen directly after stimulation. Taken together, these results add evidence that stimulation of the prefrontal cortex may represent a possible method to modulate neuronal firing within the mesolimbic system in schizophrenia.

To conclude, this study provides exploratory insights into the mechanisms of deep brain stimulation in a rodent model of schizophrenia. The results warrant further investigation in large-scale preclinical studies to shed light on the mechanisms of deep brain stimulation and ultimately inform future directions in psychiatric care.