Table 1.

Changes in DCN circuit connectivity parameters from the model of Hancock and Voigt ( 1999 )

Input population → target Frequency offset CAB (octave) Integration bandwidth BWAB (octave) Number of inputs × synaptic weight NAB × gAB
AN → T2 0.0 0.2 23.1 (26.1)
AN → WBI 0.0 2.0ab (3.0) 10.8 (8.4)
AN → T4 0.0 0.24 2.75 (4.8)
WBI → T2 0.3a (0.0) 0.05 7 (21)
WBI → T4 0.05 0.1 0 - 19.8a (9)
T2 → T4 −0.1a (0.0) 0.2 47.25
NSA → T4 N/A N/A 0.7
  • Original values are shown in parentheses when they have been changed. Input population parameters: CAB is the frequency offset of the input population from the target cell; BWAB is the integration bandwidth of the input population; NAB is the number of cells in the input population bandwidth [unlike by Hancock and Voigt (1999), NAB is determined by the bandwidth as one input unit per 1/100 octave]; gAB is the synaptic strength of the input population relative to the resting conductance of the cell. Because the product NAB × gAB, and not gAB alone, determines the net effect of each input population, only NAB × gAB is shown for comparison with original values. N/A, Not applicable; T2, type II; T4, type IV; NSA, nonspecific afferent.

  • a These changes had the largest effect on model behavior.

  • b Bandwidth is effectively 2.0 because of Gaussian-distributed weighting of inputs > 3.0 octaves, with the largest weights concentrated over a 2.0 octave bandwidth.