TRADITIONAL POSTER - ismrm

Poster Sessions
1219. Layer Specific Detection of Inhibitory FMRI Response in Somatosensory Cortex Through Cortico-
Cortical Interaction in Rats
Yoshiyuki Hirano 1 , Alan P. Koretsky 2 , Afonso C. Silva 1
1 CMU, LFMI, NINDS, NIH, Bethesda, MD, United States; 2 FMMS, LFMI, NINDS, NIH, Bethesda, MD, United States
We investigated the laminar dependence of cortico-cortical interactions induced by paired bi-lateral somatosensory stimulation in α-chloralose anesthetized
rats. When compared to the response obtained at 0 ms ISI, the BOLD percent signal change in the S1FL responding to the late stimulus was decreased by 47
% at 40 ms ISI. The degree of suppression in layers III to V was stronger than suppression of fMRI changes in layers I-II and in bottom of layer VI. Our data
shows that BOLD fMRI has sufficient spatial and temporal resolution to study cortical circuits, within functional columns and layers.
Animal fMRI: Pharmacologic Intervention
Hall B Thursday 13:30-15:30
1220. Anesthesia with Alpha-Chloralose in Rats: It Can Be Used for Longitudinal FMRI Studies
Benito de Celis Alonso 1 , Tanya Makarova 1 , Andreas Hess 1
1 Pharmacology and Toxicology, FAU Erlangen Nuremberg, Erlangen, Bayern, Germany
Animal experimentation in neurosciences requires the use of anesthetics for animal welfare and cooperation. Two of the most widely used anesthetics for
functional magnetic resonance imaging (fMRI) of animals are Isofluorane (Iso) and Alpha-Chloralose (AC). Iso is an volatile drug shown to be suitable to
obtain fMRI images at low concentrations(1). AC is an injectable anesthetic with strong functional-metabolic coupling but can create physiological
problems. Therefore, it has been used as a non recoverable. There are studies were AC was used on human patients and others were AC was used to
anaesthetize and recover dogs and cats (2,3). To our knowledge, the non-recoverable concept has not been challenged properly for fMRI. Here we present a
protocol for AC anesthetic preparation and a fMRI study that shows that AC can be used as a recoverable anesthetic and has no effects on the fMRI results
when animals are reused. Furthermore parallel behavioral studies on recovered rats show no effect on their brain and motor function.
1221. Noradrenergic Modulation of Auditory Processing in the Songbird Brain.
Colline Poirier 1 , Tiny Boumans 1 , Michiel Vellema 1 , Geert De Groof 1 , Marleen Verhoye 1 , Jacques
Balthazart 2 , Annemie Van der Linden 1
1 Bio-Imaging Lab, Antwerp, Belgium; 2 GIGA Neurosciences, Liège, Belgium
Song learning in songbirds shares a large number of features with human speech acquisition. The songbird brain is thus an excellent model to study the
neural bases of vocal learning and complex sound processing. The aim of this spin-echo BOLD fMRI study was to investigate the role of noradrenalin in
conspecific songs and bird’s own song perception. Depletion of noradrenergic inputs resulted in an enhanced differential activation by socially relevant
auditory stimuli in the secondary auditory regions of the songbird brain. These results suggest that noradrenalin might play an inhibitory role in song
discrimination.
1222. Role of Nitrite in Neurovascular Coupling: Nitric Oxide-Dependent and Independent Mechanisms
Barbora Piknova 1 , Ara Kocharyan 2 , Alan N. Schechter 1 , Afonso C. Silva 2
1 National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States;
2 National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
In addition to classic role of vasodilator, nitric oxide (NO) also acts as a neurotransmitter. NO role in neurovascular coupling and the possibility to restore
the proper brain hemodynamics after its impairment in various NO-deficiency related diseases is of major importance. We studied the fMRI response to
forepaw stimulation on á-chloralose anesthetized Sprague-Dawley rats at baseline, with NO production attenuated by nNOS inhibition and after NO and
nitrite distribution. We found that exogenous NO and nitrite restore neurovascular response and that nitrite is more effective than direct NO donor. We
hypothesize about additional vasodilatory pathways in case of nitrite metabolism.
1223. Qualitative Differences in the Brain Activation Effects of Cocaine and Mdma Determined with Bold
Fmri in Rhesus Monkeys
Kevin Sean Murnane 1 , Leonard Lee Howell 1
1 Neuroscience, Emory University, Atlanta, GA, United States
Both cocaine and methylenedioxymethamphetamine (MDMA) are drugs with a high propensity for abuse yet they have distinct behavioral and
neurochemical effects. We compared the changes in blood oxygenation elicited by cocaine (0.3 mg/kg, i.v.) and MDMA (0.3 mg/kg, i.v.) in rhesus monkeys
using BOLD fMRI. The effects of cocaine were localized to dorsal prefrontal cortex (PFC) whereas MDMA’s were localized to ventral PFC. Therefore, the
neural circuitry engaged by these compounds appears to regulate their behavioral effects. As such, the use of fMRI allows for a novel approach to determine
the mechanism of drugs of abuse.