paper on the neurochemistry of cortical auditory processing

[Peter Soros <peter.soros@xxxxxxxxx>]

I would like to draw your attention to my recent publication:

http://www.biomedcentral.com/1741-7007/4/25/abstract
http://www.biomedcentral.com/content/pdf/1741-7007-4-25.pdf

The neurochemical basis of human cortical auditory processing:
combining proton magnetic resonance spectroscopy and
magnetoencephalography

Peter Soros, Nikolaus Michael, Melanie Tollkotter  and Bettina Pfleiderer

BMC Biology 2006, 4:25

Background
A combination of magnetoencephalography and proton magnetic resonance
spectroscopy was used to correlate the electrophysiology of rapid
auditory processing and the neurochemistry of the auditory cortex in 15
healthy adults. To assess rapid auditory processing in the left
auditory cortex, the amplitude and decrement of the N1m peak, the major
component of the late auditory evoked response, were measured during
rapidly successive presentation of acoustic stimuli. We tested the
hypothesis that: (i) the amplitude of the N1m response and (ii) its
decrement during rapid stimulation are associated with the cortical
neurochemistry as determined by proton magnetic resonance spectroscopy.

Results
Our results demonstrated a significant association between the
concentrations of N-acetylaspartate, a marker of neuronal integrity,
and the amplitudes of individual N1m responses. In addition, the
concentrations of choline-containing compounds, representing the
functional integrity of membranes, were significantly associated with
N1m amplitudes. No significant association was found between the
concentrations of the glutamate/glutamine pool and the amplitudes of
the first N1m. No significant associations were seen between the
decrement of the N1m (the relative amplitude of the second N1m peak)
and the concentrations of N-acetylaspartate, choline-containing
compounds, or the glutamate/glutamine pool. However, there was a trend
for higher glutamate/glutamine concentrations in individuals with
higher relative N1m amplitude.

Conclusions
These results suggest that neuronal and membrane functions are
important for rapid auditory processing. This investigation provides a
first link between the electrophysiology, as recorded by
magnetoencephalography, and the neurochemistry, as assessed by proton
magnetic resonance spectroscopy, of the auditory cortex.



--
Dr. Peter Soros
Postdoctoral Fellow
Imaging Research
Sunnybrook Health Sciences Centre
2075 Bayview Avenue Room SG 28
Toronto Ontario M4N 3M5
Canada

Phone: 416.480.6100 ext 3843
e-mail: peter.soros@xxxxxxxxxxxxxxx

http://neuroactivity.org/