Combating cortical hypofrontality: deep brain stimulation of the mediodorsal thalamic nucleus: implications for the treatment of schizophrenia

2012-12-06T15:30:11Z (GMT) by Samuel Ewing Bernd Porr Judith Pratt
<p>Deep brain stimulation studies are underway in a wide variety of neuro-psychiatric disorders. Here we describe an exploratory study into the effect of high frequency deep brain stimulation of the mediodorsal thalamic nucleus. This study explores the regions activated by DBS of the mediodorsal thalamic nucleus through examination of immediate early genes as markers of neuronal activation and the consequences of this activation on open-field behaviours. Stimulation was delivered bilaterally with monophasic, anodic, constant current 100us duration pulses at a frequency of 130Hz delivered at an amplitude of 200uA. Brains were removed from anaesthetised animals, sectioned and radio-labeled for the IEGs<em> zif-268</em> and <em>c-fos</em>. In anaesthetised rats DBS of mediodorsal thalamic nucleus produced robust increases in the expression of <em>zif-268</em> but not <em>c-fos</em> localised to regions that are reciprocally connected with the mediodorsal thalamic nucleus, including the prelimbic and orbitofrontal cortices, and the premotor cortex indicating an increase in neural activity in these regions by a putatively antidromic mechanism.</p>