Matteo Carandini
Smith Kettlewell Eye Research Institute, United States of America
NEUROSCIENCE
 New Finding
 Controversial
|
This
paper reveals a prime example of suppression without inhibition in
sensory cortex. Using intracellular in vivo methods, the authors
studied two-tone suppression (forward masking) in primary auditory
cortex, and tested the widely held view that suppression is due to
prolonged synaptic inhibition. They discovered that suppression far
outlasts inhibition, implying that additional mechanisms, possibly
synaptic, are at work. These results resonate with earlier ones
from the visual system: two-flash suppression (forward masking) is
strong in primary visual cortex {1}, but is not due to inhibition {2}.
Both findings remind us that it is not always wise to equate
suppression of cortical responses with inhibition. The similarity
across modalities suggests once more that understanding one area of
sensory cortex will help understand the others. {1} Nelson SB, J
Neurosci 1991, 11:344-356 [PMID:1992005]; {2} Nelson SB, J Neurosci 1991, 11:369-380 [PMID:1992007].
Evaluated 12 Aug 2005 |
