Functional periodic intracortical couplings induced by structured lateral inhibition in a linear cortical network

The spatial organization of cortical axon and dendritic fields could be an interesting structural paradigm to obtain a functional specificity without postulating highly specific feedforward connections. In this paper, we investigate the functional implications of recurrent intracortical inhibition when it occurs through clustered medium-range interconnection schemes (Worgotter and Koch, 1991; Somogyi, 1989; Kritzer et al., 1992). Moreover, the interaction between the inhibitory schemes and visual orientation maps are explored. Assuming linearity, we show that clustered inhibitory mechanisms can trigger a propagation process that allows the development of extra (i.e., induced) interactions amongthe cortical sites involved in the recurrent loops. In addition, we point out how these interactions functionally modify the response of cortical simple cells and yield to highly structured Gabor-likereceptive fields. It is worthy to note that the present study should be considered not as a realistic biological model of primary visual cortex, but as an attempt to enucleate possible computational principles related to intracortical connectivity and to the underlying single-cell properties.