Simultaneous Electrophysiology and Functional Magnetic Resonance Imaging Studies in Conscious Rats

Methodological considerations in rat brain BOLD contrast pharmacological MRI

“…In some studies (Sachdev et al 2003;Khubchandani and Jagannathan 2004), positive reinforcement has been used to habituate the rat to scanner conditions. However, the use of conscious animals introduces factors such as arousal state, pain and stress caused by restraint and noise in the scanner, which may not only raise issues for consideration by institutional ethical committees, but may also alter factors such as CBF, cerebral oxygen uptake (Carlsson et al 1975) and stimulus-specific responses.…”

“…Thus, having mapped the brain regions in which BOLD changes are found in response to a drug, the function(s) of the drug in that region and the mechanisms involved are still difficult to interpret. However, greater insight into the basis of and the links between positive and negative BOLD and neuronal activity will be obtained by simultaneous electrophysiological and BOLD contrast rat brain fMRI experiments (Brinker et al 1999;Khubchandani and Jagannathan 2004). Also, understanding of the neurochemical processes underlying the phMRI response will be aided by concurrent measurements of phMRI responses and neurotransmitter release by microdialysis (Schwarz et al 2004b).…”