Modulation of input gain and response gain by noisy synaptic input
© Ayaz and Chance; licensee BioMed Central Ltd. 2009
Published: 13 July 2009
We study the responses of a single-compartment spiking model neuron. In Figure 1 (panels C and D), the model neuron receives noisy excitatory and inhibitory synaptic input arising from "pooled" (as proposed by the "normalization model" ) local cortical activity. Increasing pooled activity, as might occur from adding additional visual stimuli or changing the attentional state of the animal, led to divisive response-gain modulation of neuronal intensity curves (firing rate vs. stimulus intensity) in Figure 1C and also neuronal tuning curves (firing rate vs. stimulus parameter) in Figure 1D. When the cortical architecture is modified to include mutual interactions between cortical pools, the effects of increasing modulatory input on intensity curves (Figure 2C) and tuning curves (Figure 2D) is more like input-gain modulation. Thus, both forms of gain modulation observed in vivo can be generated by noisy synaptic input, provided the associated cortical circuitry is configured properly.
- McAdams CJ, Maunsell JH: Effects of attention on orientation-tuning functions of single neurons in macaque cortical area V4. J Neurosci. 1999, 19: 431-441.PubMedGoogle Scholar
- Treue S, Martínez-Trujillo JC: Feature based attention influences motion processing gain in macaque visual cortex. Nature. 1999, 399: 575-579. 10.1038/21176.PubMedView ArticleGoogle Scholar
- Williford T, Maunsell JH: Effects of spatial attention on contrast response functions in macaque area V4. J Neurophysiol. 2006, 96: 40-54. 10.1152/jn.01207.2005.PubMedView ArticleGoogle Scholar
- Reynolds JH, Desimone R: The role of neuronal mechanisms of attention in solving the binding problem. Neuron. 1999, 24: 19-29. 10.1016/S0896-6273(00)80819-3.PubMedView ArticleGoogle Scholar
- Reynolds JH, Pasternak T, Desimone R: Attention increases sensitivity of V4 neurons. Neuron. 2000, 26: 703-714. 10.1016/S0896-6273(00)81206-4.PubMedView ArticleGoogle Scholar
- Martínez-Trujillo JC, Treue S: Attentional modulation strength in cortical area MT depends on stimulus contrast. Neuron. 2002, 35: 365-370. 10.1016/S0896-6273(02)00778-X.PubMedView ArticleGoogle Scholar
- Heeger DJ: Normalization of cell responses in cat striate cortex. Vis Neurosci. 1992, 9: 181-197. 10.1017/S0952523800009640.PubMedView ArticleGoogle Scholar
This article is published under license to BioMed Central Ltd.