Selective attention implements the preferential routing of attended stimuli, likely through increasing the gain of the respective synaptic inputs to higher-area neurons. As the synaptic inputs conveying competing stimuli converge and intermingle on postsynaptic neurons, impeding selective attentional addressing, presynaptic circuits might be the best target of top-down signals from higher areas of attentional control. If those signals enabled presynaptic circuits to selectively entrain postsynaptic neurons, this would be a mechanism for selective routing in accordance with the Communication-through-Coherence hypothesis (CTC) [1]. Indeed, when two visual stimuli induce two gamma rhythms in separate local populations in macaque V1, only the gamma rhythm induced by the attended stimulus entrains gamma in V4 and establishes coherence [2]. Here, we modeled those electrocorticographic data [2] with a Dynamic Causal Model (DCM) for Cross-Spectral Densities (CSD) [3] and found that the selective entrainment can be caused by modulations of intrinsic V1 connections alone. Specifically, local inhibition was decreased in the granular input layer and increased in the supragranular output layer of the V1 circuit processing the attended stimulus. Our model reproduces attentional effects even in the absence of V4-to-V1 feedback connections, suggesting that a purely feed-forward mechanism can achieve the selective entrainment of V4. Thus, we propose that a mechanism of attentional addressing can act on V1 inhibitory circuitry and induce the experimentally observed effects, thereby increasing communication through coherence and implementing the selective routing of information during attention.