Accelerated high-frequency repetitive transcranial magnetic stimulation enhances motor activity in rats.

High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) is currently accepted as an evidence-based treatment option for treatment-resistant depression (TRD). Additionally, HF-rTMS showed beneficial effects on psychomotor retardation in patients. The classical HF-rTMS paradigms however are unlikely to replace electroconvulsive therapy, a more potent alternative for TRD albeit with important side-effects.

Performance Characterization of an Actively Cooled Repetitive Transcranial Magnetic Stimulation Coil for the Rat.

Objectives: This study characterizes and validates a recently developed dedicated circular rat coil for small animal repetitive Transcranial Magnetic Stimulation (rTMS).

Materials And Methods: The electric (E) field distribution was calculated in a three-dimensional (3D) spherical rat head model and coil cooling performance was characterized. Motor threshold (MT) in rats (n = 12) was determined using two current directions, MT variability (n = 16) and laterality (n = 11) of the stimulation was assessed.

Prelimbic Cortical Injections of a GABA Agonist and Antagonist: In Vivo Quantification of the Effect in the Rat Brain Using [(18)F] FDG MicroPET.

Purpose: We evaluated the glucose metabolism after microinjections of a GABAA antagonist, bicuculline, and a GABAA agonist, muscimol, in the rat prelimbic cortex (PL) by small animal positron emission tomography (μPET).

Procedures: Following a microinjection of either 0.5 μl bicuculline (0.

Small-animal repetitive transcranial magnetic stimulation combined with [¹⁸F]-FDG microPET to quantify the neuromodulation effect in the rat brain.

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neurostimulation technique for the treatment of various neurological and psychiatric disorders. To investigate the working mechanism of this treatment approach, we designed a small-animal coil for dedicated use in rats and we combined this neurostimulation method with small-animal positron emission tomography (microPET or μPET) to quantify regional 2-deoxy-2-((18)F)fluoro-d-glucose ([(18)F]-FDG) uptake in the rat brain, elicited by a low- (1 Hz) and a high- (50 Hz) frequency paradigm. Rats (n=6) were injected with 1 mCi of [(18)F]-FDG 10 min after the start of 30 min of stimulation (1 Hz, 50 Hz or sham), followed by a 20-min μPET image acquisition.

Deep brain stimulation of the prelimbic medial prefrontal cortex: quantification of the effect on glucose metabolism in the rat brain using [(18) F]FDG microPET.

Purpose: Prefrontal cortex (PFC) deep brain stimulation (DBS) has been proposed as a therapy for addiction and depression. This study investigates changes in rat cerebral glucose metabolism induced by different DBS frequencies using μPET.

Procedures: One hour DBS of the prelimbic area (PL) of the medial PFC (mPFC) (60 Hz, 130 Hz or sham) in rats (n = 9) was followed by 2-deoxy-2-[(18) F] fluoro-D-glucose ([(18) F]FDG) μPET.