Inhibitory control of visually-guided behaviour

The brain utilises cortical and subcortical pathways to transform sensory information into action, giving rise to learned and instinctive sensory-guided behaviours. How these pathways interact to generate flexible behaviour, allowing animals to react differently to the same environmental stimuli depending on circumstance, remains poorly understood. We propose that inhibitory circuits in the thalamus are essential for flexible control of sensory-guided actions. Our pilot data show that the ventral lateral geniculate nucleus (vLGN) - a prethalamic structure composed of different classes of inhibitory projection neurons - provides inhibitory control of an instinctive visually-evoked behaviour. We will identify the neural circuit mechanisms of this control and determine when it is engaged. Moreover, since the vLGN is extensively connected with visual circuits in the neocortex and the midbrain, we will test if and how this nucleus can coordinate these visual pathways to guide both instinctive and learned visually-guided behaviours. We will achieve these aims by combining genetic tools with calcium imaging, electrophysiological recordings, cell-type specific optogenetic manipulations and quantitative behaviour in animals performing visually-guided tasks. This work will generate detailed understanding of mechanisms by which the brain can orchestrate behavioural responses to environmental stimuli.