Table 2.

Summary of currently available data on gating mechanisms controlled by the cortex, the thalamus and the basal ganglia (same graphic conventions as in Figure 4).

	Gating architectures
Gating types	Gating by the cortex	Gating by the thalamus	Gating involving the basal ganglia
Brain regions involved and large-scale circuitry
Neurons at the center of the gate-triggering mechanism	Cortical neurons (e.g., from association cortex)	Projection cells of thalamic association nuclei (e.g., pulvinar)	Striatal, nigral, pallidal neurons, and projection cells from thalamic association nuclei targeted by the SNr or the GPi (e.g., mediodorsal nucleus)
Neural pathways involved in the gate-triggering mechanisms	Corticocortical projections	Corticothalamic and thalamocortical projections	Corticostriatal, nigrothalamic, pallidothalamic, and thalamocortical projections
Type of supporting experimental evidence	Electrophysiological data (Valenti and Grace, 2009)	Electrophysiological data (Floresco and Grace, 2003)	Functional magnetic resonance imaging data (McNab and Klingberg, 2008)
Type of gating interaction	Gating by entorhinal cortex of medial prefrontal cortex activity	Gating by mediodorsal thalamic nucleus of prefrontal response to hippocampus input	Role for basal ganglia in controlling access to working memory
Effect of gating signal/observation	Activity in entorhinal cortex prolongs up states in prefrontal cortex	Mediodorsal activity suppresses, or facilitates, response of prefrontal cells to hippocampus input	Correlation between activity in globus pallidus and the amount of relevant information stored in working memory