Fig. 6.

Demonstration of projections from the auditory cortex to the MPL in the rat. A: Injection site of the retrograde tracer cholera toxin beta subunit (red) in the MPL identified by TIP39-ir neurons (green). B: Retrogradely labeled neurons are visible in layer V of the primary auditory cortex and the ventral secondary auditory cortex. A lower density of labeled cells are present in layers Vi and V of the perirhinal cortex and layer VI of the ventral secondary auditory cortex. C: BDA was injected into the primary and secondary auditory cortices along the same pipette tract. E: In the same brain, anterogradely labeled fibers (green) are distributed among TIP39-ir neurons (red) in the MPL. The panels are modifications of our previously published figures (Varga et al., 2008). Abbreviations: Au1, primary auditory cortex; AuV, ventral part of the secondary auditory cortex; CP, caudate-putamen; ic, internal capsule; ILL, intermediate nucleus of the lateral lemniscus; LV, lateral ventricle; MPL, medial paralemniscal nucleus; PnO, oral part of the pontine reticular nucleus; PRh, perirhinal cortex; rs, rubrospinal tract; scp, superior cerebellar peduncle. Scale bar = 500 μm for A, B, and C, and 300 μm for D.