The dorsal lateral geniculate body (LGBd) is an impor- tant component in the circuit transmitting visual information from the retina to the higher visual centers. This structure is the main subcortical center of the visual system, the last visual information processing stage at which point-by-point descriptions of images are constructed [1, 2, 5, 8, 26]. The LGBd has long been regarded as a simple relay station. More recent studies, however, have seen the accumulation of significant amounts of data evidencing that a number of other operations are performed at the level of the LGBd. Visual recognition requires the use of various image fea- tures to allow decisions to be taken in relation to the object seen. Such signs can be characteristic structural features of an objects, such as its size, shape, position and movement in space, or color. LGBd neurons are known are known to be sensitive to a variety of image properties, including brightness, contrast, wavelength, and direction, as well as movement direction and speed [1, 5, 6, 13, 16, 29]. In addition, neurons in this sub- cortical structure, like cortical cells [15], are sensitive to the orientation of images [22, 25, 27, 30–32, 34]. Orientation is an important feature of the shapes of images and objects. The origin of the orientational selectivity of visual system neu- rons is one of the most controversial points in visual physiol- ogy. There are currently three main hypotheses for the mech- anisms of the orientational sensitivity of LGBd neurons. Adherents of the first hypothesis take the view that ori- entational selectivity properties initially arise in the visual cor- tex and the orientational sensitivity of LGBd cells results from recurrent influences from layer VI of the visual cortex [9, 33]. Another possible mechanism of the orientational sen- sitivity of LGBd neurons consists of lateral interactions of neurons within the dorsal nucleus of the lateral geniculate body. Studies of the orientational sensitivity of LGBd neu- rons in cats with lesions to visual cortex fields 17 and 18 have shown that the sensitivity of LGBd cells to the orien- tation of test bars is not influenced by the corticogeniculate projections [31]. A third group of investigators have suggested that the most likely source of the orientational sensitivity of LGBd neurons is the retina. Data have been reported which pro- vide evidence that cat and macaque retinal ganglion cells are sensitive to stimulus orientation and movement direc- tion [20, 24]. The extent of elongation of the dendritic fields of cat ganglion cells corresponds to the physiological char- Neuroscience and Behavioral Physiology, Vol. 45, No. 4, May, 2015 Experimental and Modeling Studies of Orientational Sensitivity of Neurons in the Lateral Geniculate Nucleus E. G. Yakimova 1 and A. V. Chizhov 2 0097-0549/15/4504-0465 © 2015 Springer Science+Business Media New York 465 Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova,Vol. 99, No. 7, pp. 841–858, July, 2013. Original article submitted March 12, 2013. Revised version received June 10, 2013. Experimental studies have shown that the orientation selectivity of visual stimuli is characteristic not only of cortical, but also of subcortical neurons in the dorsal nucleus of the lateral geniculate body in cats. Mathematical modeling reported here provided an analysis of the factors affecting measures of the orien- tational selectivity of neurons. Simulated responses to bar stimuli and brightness gradient stimuli were qualitatively consistent with experimental results. Non-null coefficients of selectivity may result either from an elongated receptive field shape in conditions in which the influences of saturation effects are non- linear or where the center of the receptive field is displaced relative to the center of the stimulus. Keywords: lateral geniculate body, cat, mathematical model, receptive field. 1 Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russia; e-mail: yakimova_eg@mail.ru. 2 Ioffe Physicotechnical Institute, St. Petersburg, Russia. DOI 10.1007/s11055-015-0097-5