EU: Context Sensitive Multisensory Object Recognition (HBP)

The central hypothesis or this task is that pyramidal neurons throughout the cortex act as associative elements, linking external feed-forward information about the outside world with internal feedback predictions from the brains internal representation. Objective: is to determine how feedback interacts with perceptual behaviour, using stimulation (optical and/or electrical) of single cells or small populations of neurons in a primary sensory region while imaging the effect of feedback input from perirhinal cortex on large scale population imaging throughout a cortical column. Methods: We will train animals in a licking task, where perception of single cell stimulation or microstimulation in somatosensory cortex is perceived by the animal. The effect of long range inputs on the animals’ ability to detect intracortical stimulation will be measured with optogenetic stimulation of the inputs. The effect of microstimulation and single cell stimulation on cortico-cortical circuit activation will be measured by imaging calcium signals through implanted microprisms with 2-photon imaging throughout a cortical column. The interaction between perirhinal optogenetic activation, effect on licking behaviour and on the local circuit activation will be measured. Does activation or inactivation of feedback inputs to somatosensory cortex, affect when or whether the animal licks? Does the activation or inactivation of feedback inputs affect the number of neurons activated in cortical column by the microstimulus.