Depressing synapses detect neural synchrony

[Walter Senn]

New paper available (to appear in Neural Computation):
 

             READING NEURONAL SYNCHRONY WITH DEPRESSING SYNAPSES

                  Walter Senn, Idan Segev, Misha Tsodyks

According to recent experiments of deCharms and Merzenich (Nature 381, 
610-613 (1996)), neurons in the primary auditory cortex of the monkey do 
not change their mean firing rate during an ongoing tone stimulus. The only 
change which is measured during the tone is a enhanced correlation among 
the individual spike trains of the auditory cells. We show that this 
coherence information in the auditory cell population could easily be 
extracted by a postsynaptic neuron using depressing synapses.
The idea is that a dynamically depressing synapse shows a high response at 
a burst onset and then gets depressed towards the burst end. 
If some of the auditory cells now synchronize their bursts, the high 
postsynaptic responses at the burst onset may be enough to activate a 
postsynaptic cell. Such a partial synchronization may be possible while the 
mean firing rate of the whole auditory cell population still remains constant 
before and during the tone stimulus. In this case the tone would never have 
been detected by a postsynaptic cell using static synapses with constant 
weights.


The manuscript (170 KB) can be downloaded from: 
http://iamwww.unibe.ch:80/~brainwww/publications/pub_walter.html