Skip to main content
Figure 9 | Cerebrospinal Fluid Research

Figure 9

From: In normal rat, intraventricularly administered insulin-like growth factor-1 is rapidly cleared from CSF with limited distribution into brain

Figure 9

Nissl-stained histologies (A and C) and adjacent autoradiograms (ARG's) at 30 min after 125I-IGF-1 infusion for the two subarachnoid velae, the velum interpositum (A and B, respectively; bregma -4.3 mm) and the superior (anterior) medullary velum (C and D, respectively; bregma -9.2 mm). 9A. Starting at the subfornical organ and running caudad along the roof and upper sides of the third ventricle (3 V), the velum interpositum separates the 3 V from the subarachnoid space within it. The 3 V is clear and featureless, whereas the velum interpositum is filled with typical arachnoid tissue, e.g., trabeculae and blood vessels. The thalamus is the brain structure comprising the lower half of the figure. 9B. At 30 min, there was some radioactivity in the 3 V and the contralateral velum (left side) and much more in the ipsilateral velum. The dark spot at the bottom of the ARG came from 125I-activity within the mammillary recess of the 3 V. 9C. The superior medullary velum (SMV) forms the posterior wall of the recess of the inferior colliculus (this recess is an outpouching ofthe aqueduct and not shown) and the anterior roof of the fourth ventricle, mostly in the vicinity of the cerebellum; it contains subarachnoid CSF and tissue. 9D. The very dark "A-shaped" figure in the middle of this ARG indicates radioactivity that has collected over 30 min in the CSF and tissue of the SMV. The grayness within the legs of the upright "A" indicates some diffusion into the cerebellar lobe from the SMV. The legs and crossbar of the inverted "A" in the lower middle of the ARG represent radioactivity within the SMV on the ventral side of the cerebellar lobe (the SMV is not visible on the histology at this magnification, Fig. 9C; it can be seen to be subarachnoid tissue in Fig. 6 of Ghersi-Egea et al. [14]. The lighter spot within the lower part of the inverted "A" arises from CSF signal within the fourth ventricle. The faint figures in the rest of this ARG indicate radioactivity in several midbrain cisterns of the subarachnoid system at 30 min. Scale bar = 0.6 mm.

Back to article page