Animal Hydrocephalus
Animal Hydrocephalus Pre-meeting 24th June 2009
Peter Froggatt Centre, Queen's University, Belfast, Northern
Ireland
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 Aging
Models: Implications for Hydrocephalus and Neurodegeneration.
He explored the idea that changes in the CSF with aging 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 blood brain barrier transporter RAGE and the
glial markers, GFAP and OX6 increased with age whereas BRDU, the
marker for stem cell division decreased. Aging rats performed
less well on the Morris water maze test. He discussed gene
methylation status of the BBB RAGE/LRP-1 transporters and argued
that there is a case for early intervention to prevent the
metabolic cascade leading to cognitive deficits associated with
normal pressure hydrocephalus and 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.
