Are perhaps some psychedelic fMRI observations a result of neurovascular, and not strictly neuronal, effects!?

We found that the psychedelic, DOI, markedly altered neurovacular coupling in a regionally specific manner. This effect has grand implications for fMRI, for instance, neuronal vs hemodynamic measures of resting state function connectivity massively differed.

Classic psychedelics 🍄have a strong affinity 💪for a number of serotonin receptors, and of particular importance, the sub type 5-HT2A. Considered collectively, we hypothesized that psychedelics have potent neurovascular effects that could confound interpretation of BOLD-fMRI.

Why would psychedelics alter NVC? 🤷

In 1946, a compound ⚗️was discovered that contracted blood. Cleverly, it was named serotonin, the combo of words serum (blood) and tone (vasoactive effects). Only years later was it discovered to have potent neuromodulatoty effects.

Neurovascular coupling (NVC)?! Who cares!?

NVC is a process that links 🖇️neuronal activity to hemodynamics. BOLD-fMRI is sensitive to hemodynamics, which indirectly indexes neuronal activity. So, to accurately interpret psychedelic fMRI , 🔊 !NVC must considered! 🔊

Psychedelic BOLD-fMRI studies have made dramatic claims about how 🍄 change 🧠. But one tiny problem 🤏- those studies are measuring hemodynamic- dependent signals, not neuronal signals! 🫣😱😮