RT Journal Article
SR Electronic
T1 Optimality and Robustness of a Biophysical Decision-Making Model under Norepinephrine Modulation
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 4301
OP 4311
DO 10.1523/JNEUROSCI.5024-08.2009
VO 29
IS 13
A1 Philip Eckhoff
A1 K. F. Wong-Lin
A1 Philip Holmes
YR 2009
UL http://www.jneurosci.org/content/29/13/4301.abstract
AB The locus ceruleus (LC) can exhibit tonic or phasic activity and release norepinephrine (NE) throughout the cortex, modulating cellular excitability and synaptic efficacy and thus influencing behavioral performance. We study the effects of LC–NE modulation on decision making in two-alternative forced-choice tasks by changing conductances in a biophysical neural network model, and we investigate how it affects performance measured in terms of reward rate. We find that low tonic NE levels result in unmotivated behavior and high levels in impulsive, inaccurate choices, but that near-optimal performance can occur over a broad middle range. Robustness is greatest when pyramidal cells are less strongly modulated than interneurons, and superior performance can be achieved with phasic NE release, provided only glutamatergic synapses are modulated. We also show that network functions such as sensory information accumulation and short-term memory can be modulated by tonic NE levels, and that previously observed diverse evoked cell responses may be due to network effects.