The impact of behavioral state and spatial attention on sensory responses in the primary visual thalamus - PROJECT SUMMARY/ABSTRACT
While significant advances have been made over the past decade in understanding how sensory responses are
modulated in the awake behaving animal, significant gaps in our knowledge still remain about how non-sensory
internal factors related to changes in behavioral state can impact sensory signaling. First, our current
understanding of how visual signaling is modulated by behavioral state is still limited to cortex with less emphasis
on the inputs to cortex such as those coming from the thalamus, which is a brain region strongly modulated by
changes in behavioral state. Second, while it has been widely recognized that spontaneous factors such as
running, whisking, and changes in arousal can modulate visual activity, very few studies take these factors into
account. Without accounting for non-sensory factors, we cannot fully understand the neural circuitry underlying
sensory responses during active behavior. Thus, as the field of systems neuroscience moves towards
understanding sensory processing in awake behaving animals, there is a critical need to understand how early
sensory processing is modulated by shifts in the waking behavioral state. The proposed project will combine the
recording of non-sensory internal factors such as arousal and spontaneous face movements with simultaneous
extracellular recordings from the dorsal lateral geniculate nucleus (dLGN) of the thalamus while animals are
actively performing a visual spatial detection task.
By dissociating non-sensory variables such as arousal and movement from task engagement and visual
spatial attention, I can test my main hypothesis that shifts in arousal, task-engagement, and spatial attention,
have distinct effects on activity in dLGN. This hypothesis will be tested through three Aims. First, in Aim 1 I will
determine the relationship between arousal level, face movement, and visual response properties in dLGN in
mice passively viewing visual stimuli. In Aim 2, I will quantify how stimulus detection accuracy in a behavioral
task impacts visual response properties in dLGN while simultaneously recording non-sensory variables, and use
neural data combined with non-sensory factors to predict behavioral outcome on a trial-by-trial basis with a
generalized linear model (GLM) to understand which predictors significantly contribute to behavioral outcome.
In Aim 3, I will determine how visual spatial attention modulates visual responses in dLGN while recording non-
sensory variables and dissociate changes in cognitive state from changes in arousal and movement to gain a
more complete understanding of the circuit mechanisms of visual spatial attention. Together, these experiments
will yield a detailed characterization of how sensory activity and non-sensory activity can be both complementary
and dissociable at the level of dLGN. This work will underscore both a critical need to account for non-sensory
internal variables, and the impact of shifts in behavioral state on early visual signals.