Parvalbumin interneurons contribute to spontaneous hemodynamic fluctuations

Area of Science:

• Neuroscience
• Systems Neuroscience
• Neurovascular Coupling

Background:

• Resting-state hemodynamic fluctuations are linked to neural activity, but the specific cell types driving them are unknown.
• Parvalbumin (PV) neurons are implicated in gamma oscillations, making them key candidates for driving these fluctuations.

Purpose of the Study:

• To investigate the role of PV interneurons in spontaneous neurovascular dynamics.
• To determine if PV neurons modulate resting-state neural activity, EEG, and hemodynamics.

Main Methods:

• Utilized chemogenetic tools in PV-Cre mice to modulate PV interneuron activity.
• Employed two-photon calcium imaging to monitor neural and vascular changes.
• Measured EEG and cerebral blood flow (CBF) under varying PV neuron activity levels.

Main Results:

• Chemogenetic suppression of PV neurons reduced EEG gamma power and increased low-frequency activity.
• PV suppression led to elevated basal CBF and altered vascular dynamics in deeper cortical layers.
• The correlation between EEG gamma power and CBF was significantly weakened upon PV suppression.

Conclusions:

• PV interneurons contribute to spontaneous neurovascular dynamics.
• PV neurons play a significant role in linking gamma oscillations to resting-state hemodynamic signals.
• These findings highlight the importance of PV interneurons in neurovascular changes during non-task states.