Experimental Hydrocephalus Pre-meeting 24th June 2009
Authors: Hazel Jones
Background
This was the 9th session on animal hydrocephalus held
since they were initiated in Atlanta, USA in 2000. The aim
has been to give researchers who are presenting animal studies at
the main meeting, the opportunity to present their work in an
informal atmosphere with time for feedback and useful discussion
from the audience which usually amounts to 20 - 40 people.
This year the first talk was from Pat McAllister (University of
Utah) on "CSF and Capillary Pulsatility in Hydrocephalus"
in which he described some MRI experiments to measure the CSF
stroke volume in the aqueduct of hydrocephalic rats using a 9.4
Tesla magnet. He went on to report measurements of the
capillary pulse index in normal and hydrocephalic rats, using a
2-photon laser scanning microscope through a cranial window with
promising results. The second talk was by Dorte Clemmensen,
Neurosurgery, Aarhus University Hospital, on "Experimental
Tethered Cord - a New Model". Tethered cord is a big problem
in children with myelomeningocele and this group has been working
to produce a pig model for future study. Using kaolin injections
into the spinal cord they have been following the effects with MRI
and are on the verge of success. The third talk was by
Agustin Castaneyra- Perdomo, Universidad de La Laguna, Tenerife, on
"Arterial Hypertension Effects on Choroid Plexus brain
barriers". He described experiments to
identify CSF and choroid plexus changes in the spontaneously
hypertensive rat (SRH). Some proteins, S100β, transthyretin and α1
antitrypsin were increased in hydrocephalus but many others were
decreased. He suggested that the proteins behave similarly to
Alzheimer's disease markers and that the SHR rat has disturbances
of the blood brain and blood CSF barriers.
After a coffee break, Conrad Johanson, Brown University, spoke
on "Molecular, Cognitive and Epigenetic Profiling for
Ageing Models: Implications for Hydrocephalus and
Neurodegeneration". He explored the idea that
changes in the CSF with ageing may threaten ongoing
neuroregeneration in the subventricular zone and dentate gyrus,
particularly in relation to changes in Aβ peptide and its
transporters. Using 3 month versus 30 month-old rats they
showed that Aβ, the transporter RAGE and the glial markers, GFAP
and OX6 increased with age whereas BRDU, the marker for cell
division decreased. Aging rats performed less well on the
Morris water maze test. He argued that there is a case for early
intervention to prevent the cascade leading to Alzheimer's
disease. Pat McAllister gave the next talk entitled:
"Neuroinflammation in Neonatal
Hydrocephalus". In a rat model with
communicating hydrocephalus induced by kaolin, inflammatory
cytokines were found in the cerebral cortex only. Using a more
extreme model of hydrocephalus by induction at 1-2 days, they
studied gene expression in the cerebral cortex using micro arrays
and unique probe sequences. They found that out of 41,012 sequences
1,824 were changed at least 1.5 fold. Further analysis identified
specific gene categories and individual genes that were affected.
This was followed by the last talk by Janet Miller, Central
Michigan University, "In Hydrocephalus, do Protein Levels
Correlate with Gene Expression?" Janet has followed up her
previous study using the H-Tx rat with inherited hydrocephalus
where a number of genes had been shown to be linked to
hydrocephalus. She argued that a more direct and potentially useful
approach would be to study protein expression and using blotting
techniques investigated the protein products of the altered genes
found in the expression study. Interestingly, the direction of
protein expression was often either opposite to the gene expression
or showed no change.
Overall, this proved to be a most interesting morning provoking
much discussion and we hope useful feedback for the presenters.
Materials and Methods
Results
Conclusions
Hazel Jones E-Mail: srhsb@btinternet.com
Pat McAllister E-Mail:
pat.mcallister@hsc.utah.edu
Dorte Clemmensen E-Mail:
daarupclemmensen@hotmail.com
Agustin Castaneyra-Perdomo E-Mail:
acastane@ull.es
Conrad Johanson E-Mail:
Conrad_Johanson@brown.edu
Janet Miller E-Mail: Mille16j@cmich.edu
