Bridges of dorsoventrally oriented labeled axons span the relatively label-poor Stratum Album Intermedium. 
In adult hamsters, this projection is completely restricted to the deep laminae, primarily the Stratum Album Intermedium.
A large number of these neurons were located in the deep layers and many were in the Stratum Album Intermedium (SAI).
For this study, we examined the optic (stratum opticum, SO), intermediate gray (stratum griseum intermedium, SGI), intermediate white (Stratum Album Intermedium, SAI), and deep gray (stratum griseum profundum, SGP) layers.
Deposits of PHA-L into V nucleus principalis (PrV) produced labelled axons and boutonlike swellings in the lower stratum griseum intermediale (SGI) and upper Stratum Album Intermedium (SAI) in the SC bilaterally.
The light microscopic studies showed that the nigrotectal fibres, which had been identified by anterograde transport of horseradish peroxidase from the substantia nigra, terminated in a distinctive clustered pattern throughout the rostrocaudal extent of the stratum griseum intermedium, Stratum Album Intermedium and adjacent dorsal portion of the stratum griseum profundum of the ipsilateral superior colliculus. The tectospinal neurons, which had been identified by retrograde transport of horseradish peroxidase from the spinal cord, had mainly large-sized somata, were stellate in shape with multiple long dendrites, and formed variable-sized clusters of 4-15 neurons within lateral regions of the ventral Stratum Album Intermedium and dorsal stratum griseum profundum. Electron microscopic examination of the superior colliculus following ibotenic acid lesions in the substantia nigra and horseradish peroxidase injections in the spinal cord showed multiple degenerating nigrotectal boutons in synaptic contact with the soma and the mainstem and secondary dendrites of labelled tectospinal neurons in the lateral regions of the Stratum Album Intermedium and stratum griseum profundum of the superior colliculus.
This pathway terminated as a series of patches along the border between the stratum griseum intermediale and Stratum Album Intermedium and encompassed approximately 75% of the rostrocaudal extent of the colliculus.
Of the total sample of 52 cells, 7.7% had their somata in the stratum griseum intermediale (SGI), 50% were in the Stratum Album Intermedium (SAI), 36.5% were in the stratum griseum profundum (SGP), and 5.8% were in the stratum album profundum (SAP).
Two of the recovered neurons were located in the stratum griseum superficiale (SGS), three were in the stratum opticum (SO), ten were in the stratum griseum intermediale (SGI), 11 were in the Stratum Album Intermedium (SAI), 11 were in the stratum griseum profundum (SGP) and two were located in the stratum album profundum (SAP).
The HRP experiments demonstrated that the cells of origin of the intertectal pathway were located primarily in the rostral stratum griseum intermediale ( SGI ), Stratum Album Intermedium (SAI) and stratum griseum profundum (SGP).
The uncrossed pathway terminated primarily as a series of patches throughout the mediolateral and rostrocaudal extents of the lower stratum griseum intermediale and Stratum Album Intermedium.
(1974), the axons of these cells terminate in lower Stratum griseum superficiale and in Stratum opticum, Stratum griseum intermedium and Stratum Album Intermedium of SC.
Both sets of fibers end only in the caudal half of the colliculus, predominantly in the Stratum Album Intermedium.
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