Figure 7.

Comparison of results from cortical and LD neurons suggests amygdala–cortical coupling. A schematic of the time courses (x-axis, time after delivery in seconds) of the taste responses observed previously (Katz et al., 2001a) in taste cortex (top) and in LD neurons (bottom) is shown. The two progress through a similarly timed sequence of three response “epochs”: one lasting until ∼0.25 s, a second lasting from ∼0.25 to ∼1.0 s, and a third beginning at 1.0 s after taste administration. The first epoch appears largely identical for LD and cortical neurons; both provide information about the presence of a taste on the tongue (“Detection”) but neither provides discriminative information about which taste is which. Information about palatability is available in LD neurons during the second epoch, whereas cortex conveys information about the identity of the taste regardless of its palatability (i.e., responses to palatability-specific pairs of tastes are not particularly similar). Finally, in the third epoch, palatability-related information appears in cortex, perhaps reflecting transmission from BLA. The third epoch of LD BLA responses remains mysterious at this time.