Thread by @KernelCo

Interested in the effect of #psychedelics on the brain? Did you know you can image the cortex and extract valuable physiological information at the same time in an ecologically valid setup? We used @kernelco Flow1 to do exactly that! A #tweeprint:

https://twitter.com/biorxiv_neursci/status/1612573903930511380

Flow1 is a Time Domain (TD) fNIRS device, which measures cortical brain activity (oxy- and deoxy-hemoglobin concentrations) and physiology such as pulse rate (PR) and pulse rate variability (PRV).

In our study, 15 participants underwent subanesthetic #ketamine and saline injections. First, we found that ketamine administration caused significant changes in systemic physiology: increase in PR and decrease in PRV.

Next, we looked at fractional Amplitude of Low Frequency Fluctuations (fALFF), a proxy for local neuronal activity. We found a significant reduction in whole-brain fALFF during the ketamine session, compared to the saline control!

What about functional connectivity (FC) directly after ketamine injection? The literature on this is mixed, but we found a reduction in global brain connectivity (GBC) of the prefrontal region. Oh and FC derived from Flow shows hallmark features: community structure & homotopy!

Now, one predictor of outcome measures in #psychedelics therapy is the intensity of mystical experiences. Can we predict this with neural/physiological features from Kernel Flow? Yes! Turns out the peak of experience following ketamine administration varies from person to person.

Whole head TD-fNIRS is an ecologically valid methodology to measure acute/delayed physiological and neural changes following pharmacological interventions. This scalable technology can be deployed in clinics to shine light (pun intended) on the impact of drugs targeting the brain

Stay tuned for more exciting news from @KernelCo
Special thanks to all coauthors:
A. Castillo, @neurexplorer, @RyanMField, F. Fishburn, A. Gundran, W. Ho, @CyberMonkSam, @juliankh, @Zahra_M_Aghajan , N. Miller, K. Perdue, J. Phillips, W. Ryan, M. Shafiei, @FScholkmann, M. Taylor