Frequency-Dependent Modulation of the Prefrontal Cortex by Low-Intensity Focused Ultrasound: Impact on Mesolimbic...

Area of Science:

• Neuroscience
• Neuromodulation
• Neurotransmission

Background:

• Synchronized neural oscillations are crucial for cognitive functions.
• Low-intensity focused ultrasound (LIFU) shows potential for modulating neurotransmission.
• Targeted neuromodulation requires precise control over neural circuits.

Purpose of the Study:

• To investigate the effects of frequency-modulated LIFU on dopamine release and neural activity.
• To determine if LIFU can selectively excite or inhibit dopaminergic signaling in the nucleus accumbens (NAcc) core.
• To explore the influence of oscillation frequency and sex on LIFU's neuromodulatory effects.

Main Methods:

• Frequency-modulated LIFU was applied to the prelimbic cortex (PLC) in rats.
• Dopamine release in the NAcc core was measured using electrochemical methods.
• Neuronal and astrocytic activity was assessed via cFOS and GFAP expression.
• Histological analysis was performed to evaluate cell viability.

Main Results:

• LIFU modulated NAcc dopamine release (excitation or inhibition) for up to 90 minutes, dependent on frequency and sex.
• Specific frequency combinations (e.g., theta-coupled beta) reduced dopamine release and GFAP levels.
• Other frequencies (e.g., theta-coupled gamma) increased dopamine release, with sex-specific responses.
• LIFU elevated neuronal activation (cFOS) and, in some cases, astrocytic marker (GFAP) in the PLC without causing cell death.

Conclusions:

• Frequency-tuned LIFU stimulation of the PLC offers a novel method for selective neuromodulation.
• This approach can precisely control dopaminergic signaling in the NAcc.
• LIFU presents a promising tool for targeted manipulation of neurotransmission with potential therapeutic applications.