Characterization of response properties in the mouse lateral geniculate nucleus

Abstract

The lateral geniculate nucleus (LGN) has been increasingly recognized to actively regulate information transmission to primary visual cortex (V1). Although efforts have been devoted to study its morphological and functional features, the full array of response characteristics in mouse LGN as well as their dependency on subjective state have been relatively unexplored. To address the question we recorded from mouse LGN with multisite-electrode-arrays (MEAs). From a dataset with 185 single units, our results revealed several exceptional response features in mouse LGN. We also demonstrated that subtypes, such as ON-/OFF-centre and transient/sustained cells exhibited functionally distinctive features, which might indicate parallel projections. To further compare response features from the full extent of mouse LGN, we developed a three-dimension (3D) LGN volume through histological approach. This volume explicitly captures morphological features of mouse LGN and provides the preciseness to classify location of single neuron into the anterior/middle/posterior LGN. Based on this categorization, we showed that response features were not regionally restricted within mouse LGN. We further examined neural activity with subjects in high or low isoflurane states. The distinct features in LFPs between the two states indicated that adjusting isoflurane concentration could provide a reliable and controllable experimental model to explore the state-dependent neural activity in mouse visual system. Subsequently, our results demonstrated that properties, including response latency, contrast sensitivity and spatial frequency properties were modulated by isoflurane concentration. Our current work suggests that mouse LGN can dynamically regulate information transmission to the cortex using numerous mechanisms, including responding mode, modulation of neuronal responses according to subjects’ states.