Transcript Krystle Frahm - GK-12 Biosensor Program at Colorado State

Vascularization in the
Paraventricular Nucleus
(PVN) of the Hypothalamus
Krystle Frahm
October 5, 2010
Where is it?
PVN 
PVN 
Sagital view
Coronal view
What does the PVN contain?
• Magnocellular cells (released into the
posterior pituitary)
– Oxytocin
– Vasopressin
• Parvocellular cells (median eminence to
anterior pituitary)
– Corticotropin-releasing hormone
– Vasopressin
– Thyrotropin-releasing hormone
My research focus
• Early events during development
– Migration
– Early stress
• The second angiogenesis period in the
PVN
• How might angiogenesis in the embryonic
brain impact the adult
Angiogenesis
• Angiogenesis – the growth of new blood
vessels from pre-existing ones
• Without proper CNS vascularization,
apoptosis occurs and the embryo dies
• Purpose
– Provide nutrients and gas exchange to
underlying neural tissue
– Blood-brain barrier
(as reviewed in Mancuso et al., 2008)
Angiogenesis animation
• http://www.youtube.com/watch?v=7YgwJe
VEgvU
Why study vascularization?
• Recently found that the increase in
vascularization in the PVN occurs
postnatally
P4
P8
P12
P19
• Is the vascular susceptible to alterations?
Relationship between neurons
and blood vessels
• Vasopressinergic elements are in direct
relationship with the hypothalamic
vasculature
– May serve as osmoreceptors of the blood
flowing through capillaries and provide
feedback for VP modification
(Ray & Choudhury, 1990)
GABA(B) receptors influence
angiogenesis in the PVN
Wild Type
Knockout
Trend toward differences in Males & Females
Slovenia
• SF-1 mice – KO’s are born without gonads
and adrenal glands
– effect on endogenous sex hormones on PVN
blood vessel density
• Dexamethasone (dex )treatment (E11-18)
– Prenatal dex in rats
• Decrease in body weight
• Decreased HPA activity
• Vasopressin mRNA was increased
(Burlet et al., 2005)
Slovenia cont.
• Animals were killed postnatal days 4, 8, 12
• Currently being processed to visualize
vascularization
• Branch points will assess vascular density
• Findings will suggest whether endogenous
sex hormone and/or early stress alters the
vascularization in the PVN
Tie2-GFP
In vitro angiogenesis?
Questions?