Single-pulse electrical stimulation methodology in freely moving rat.

Background: Cortico-cortical evoked potentials (CCEP) are becoming popular to infer brain connectivity and cortical excitability in implanted refractory epilepsy patients. Our goal was to transfer this methodology to the freely moving rodent.

New Method: CCEP were recorded on freely moving Sprague-Dawley rats, from cortical and subcortical areas using depth electrodes.

The Impact of Repetitive Transcranial Magnetic Stimulation on Functional Connectivity in Major Depressive Disorder and Bipolar Disorder Evaluated by Directed Transfer Function and Indices Based on Graph Theory.

The objective of this work was to study the impact of repetitive Transcranial Magnetic Stimulation (rTMS) on the EEG connectivity evaluated by indices based on graph theory, derived from Directed Transfer Function (DTF), in patients with major depressive disorder (MDD) or with bipolar disorder (BD). The results showed the importance of beta and gamma rhythms. The indices , and increased in MDD responders in beta and gamma bands after rTMS.

EEG Phase Synchronization in Persons With Depression Subjected to Transcranial Magnetic Stimulation.

The main objective of this work was to study the impact of repetitive Transcranial Magnetic Stimulation (rTMS) treatment on brain activity in 8 patients with major depressive disorder (MDD) and 10 patients with bipolar disorder (BP). Changes due to rTMS stimulation of the left dorsolateral prefrontal cortex (DLPFC) were investigated considering separately responders and non-responders to therapy in each of both groups. The aim of the research is to determine whether non-responders differ from responders suffered from both diseases, as well as if any change occurred due to rTMS across consecutive rTMS sessions.

Complexity Analysis of EEG Data in Persons With Depression Subjected to Transcranial Magnetic Stimulation.

The aim of this work was to study the neurophysiological effect of repetitive transcranial magnetic stimulation (rTMS) applied to the left dorsolateral prefrontal cortex (DLPFC) in 8 patients with major depression disorder (MDD) and 10 patients with bipolar disorder (BP), considering separately responders and non-responders to rTMS therapy in each of both groups. The Higuchi's Fractal Dimension (FD) was analyzed from 64-channels EEG signals in five physiological frequency bands and every channel separately. Changes of FD were analyzed before and after 1st, 10th, and 20th session of rTMS.

Acetylcholine modulates human working memory and subsequent familiarity based recognition via alpha oscillations.

Working memory (WM) can be defined as the ability to maintain and process physically absent information for a short period of time. This vital cognitive function has been related to cholinergic neuromodulation and, in independent work, to theta (4-8Hz) and alpha (9-14Hz) band oscillations. However, the relationship between both aspects remains unclear.

Resting electroencephalographic correlates of the clinical response to repetitive transcranial magnetic stimulation: A preliminary comparison between unipolar and bipolar depression.

Background: Major depressive disorder (MDD) and bipolar disorder (BP) are two different types of mood disorders, sometimes difficult to distinguish from their depressive symptoms, and for which repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) has been proposed to treat refractory patients. Here we studied whether the electroencephalogram (EEG) at rest could be used to predict the therapeutic response to left DLPFC 10 Hz rTMS, and to which extent BP and MDD patients show similar correlation between the clinical response and the cortical networks at rest.

Methods: Eight MDD (6 females) and 10 BP patients (6 females) were included.

Changes of oscillatory brain activity induced by repetitive transcranial magnetic stimulation of the left dorsolateral prefrontal cortex in healthy subjects.

Repetitive transcranial magnetic stimulation (rTMS) modulates brain activity in different ways according to the stimulation parameters. Although the after-effects of rTMS over motor cortex are well documented in healthy individuals, less is known about the stimulation of dorso-lateral prefrontal cortex (DLPFC). Here, we studied in 20 healthy subjects how cortical oscillations are modulated by four different active rTMS protocols (1Hz, 10Hz, continuous and intermittent theta bursts - cTBS and iTBS) of the left DLPFC, and by a sham protocol used as a control condition, by comparing the spectral power of pre- and post-rTMS electroencephalographic (EEG) recordings of 15min duration.