PMID- 11110123
OWN - NLM
STAT- MEDLINE
DCOM- 20010118
LR  - 20191210
IS  - 0899-7667 (Print)
IS  - 0899-7667 (Linking)
VI  - 12
IP  - 11
DP  - 2000 Nov
TI  - Dynamical mechanism for sharp orientation tuning in an integrate-and-fire model 
      of a cortical hypercolumn.
PG  - 2473-511
AB  - Orientation tuning in a ring of pulse-coupled integrate-and-fire (IF) neurons is 
      analyzed in terms of spontaneous pattern formation. It is shown how the ring 
      bifurcates from a synchronous state to a non-phase-locked state whose spike 
      trains are characterized by clustered but irregular fluctuations of the 
      interspike intervals (ISIs). The separation of these clusters in phase space 
      results in a localized peak of activity as measured by the time-averaged firing 
      rate of the neurons. This generates a sharp orientation tuning curve that can 
      lock to a slowly rotating, weakly tuned external stimulus. Under certain 
      conditions, the peak can slowly rotate even to a fixed external stimulus. The 
      ring also exhibits hysteresis due to the subcritical nature of the bifurcation to 
      sharp orientation tuning. Such behavior is shown to be consistent with a 
      corresponding analog version of the IF model in the limit of slow synaptic 
      interactions. For fast synapses, the deterministic fluctuations of the ISIs 
      associated with the tuning curve can support a coefficient of variation of order 
      unity.
FAU - Bressloff, P C
AU  - Bressloff PC
AD  - Department of Mathematical Sciences, Loughborough University, Leicestershire, UK.
FAU - Bressloff, N W
AU  - Bressloff NW
FAU - Cowan, J D
AU  - Cowan JD
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Neural Comput
JT  - Neural computation
JID - 9426182
SB  - IM
MH  - Action Potentials
MH  - Animals
MH  - *Models, Neurological
MH  - *Neural Networks, Computer
MH  - Neurons/*physiology
MH  - Synaptic Transmission/*physiology
EDAT- 2000/12/08 11:00
MHDA- 2001/02/28 10:01
CRDT- 2000/12/08 11:00
PHST- 2000/12/08 11:00 [pubmed]
PHST- 2001/02/28 10:01 [medline]
PHST- 2000/12/08 11:00 [entrez]
AID - 10.1162/089976600300014809 [doi]
PST - ppublish
SO  - Neural Comput. 2000 Nov;12(11):2473-511. doi: 10.1162/089976600300014809.