Researchers at the Indian Institute of Technology (IIT), Mandi and the National Brain Research Centre, in collaboration with the University at Buffalo, have performed mathematical simulation studies on non-invasive brain simulation techniques.
The results of the team's recent work in the area have been published as an abstract in the journal Brain Stimulation.
According to the team, transcranial electrical stimulation (tES) is a non-invasive brain stimulation technique that passes an electrical current through sections of the brain to study or alter brain function.
"We simulated a physiologically detailed mathematical model of the neurovascular unit (NVU) with four compartments: synaptic space, astrocyte space, perivascular space, and arteriole smooth muscle cell space, called NeuroVascular Units or NVU," said Shubhajit Roy Chowdhury, associate professor, School of Computing and Electrical Engineering, IIT Mandi.
The mathematical model involved the application of perturbations of varying frequencies (0.1 Hz to 10 Hz) to simulate the electrical field to the four nested NVU compartmental pathways and analysed the changes in blood vessel diameter in response to the frequencies.
Three types of non-invasive brain stimulation transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS) and transcranial oscillatory current stimulation (tOCS) were modelled to investigate their physiological effects.
The initial tES effects on the blood vessels were also found to occur via the perivascular space - a fluid-filled space surrounding the blood vessels in the brain.
"Our study can help brain- and neuro-specialists plan patient-specific restorative neurorehabilitation activities for stroke, post traumatic brain injury, mild cognitive impairment, dementia, and other neuropsychiatric disorders.
"Such a mathematical model-based quantitative analysis would help in individualised therapeutic protocols for neuropsychiatric disorders. The team has planned experimental studies that involve blocking of various pathways to validate their modelling results," Chowdhury said.