Figure 2.

Connections of the prefrontal cortex with physiologically characterized regions of the belt and parabelt auditory cortex. (a) Color-coded schematic of the core (purple) and belt (yellow) region of the auditory cortex. (b) Physiological map of recordings from the lateral belt region. Numbers indicate the best center frequency for each electrode penetration (black or white dots) in kHz. Injections of different anterograde and retrograde tracers (colored regions) are shown with respect to these recordings. The boundaries of antero-lateral belt auditory cortex (AL), middle-lateral belt auditory cortex (ML), and caudal-lateral belt auditory cortex (CL) are delineated by a bounded line and are derived from the frequency reversal points. (c) Three coronal sections through the prefrontal cortex indicating anterograde and retrograde labeling, which resulted from the color-coded injections placed in the lateral belt/parabelt auditory cortex in (b). (d) A summary of the projections from rostral and caudal auditory cortex showing that dual streams emanating from the caudal and rostral auditory cortex innervate dorsal and ventral prefrontal cortex, respectfully. Adapted from Romanski et al. (1999b). NCR, no clear response.