student research day - Case Western Reserve University School of ...

Lynnel (Kate) Donatto
EPO Treatment for Impaired Dendritic Spine Formation Due to Placental Insufficiency
Lynnel Donnatto and Dr. Shenandoah Robinson
Department of Neurosciences
Case Western Reserve University, School of Medicine
Placental insufficiency is a complication of pregnancy that is associated with an
increased risk for premature delivery and neurological and intellectual impairments
including mental retardation, cerebral palsy and epilepsy. Our preliminary data suggest
placental insufficiency impairs KCC2 expression in infants born preterm, compared to their
peers born at term. The KCC2 transporter is a neuron-specific K-Cl co-transporter that
induces the developmental switch of GABAergic synapses from excitatory to inhibitory, and
it has been shown that damage to this transporter leads to a greater seizure propensity in
preterm infants. In addition to regulating the intracellular chloride gradient, KCC2 is a key
factor in normal neuronal branch and dendritic spine formation. We hypothesize that
placental insufficiency will hinder KCC2 expression and thus dendritic spine formation, and
result in a lower seizure threshold. Determining to what extent placental insufficiency
results in abnormal KCC2 expression will enhance the development of effective neonatal
interventions and one such treatment may be EPO. The cytokine EPO is essential for
neuronal differentiation during brain development. We will evaluate whether neonatal EPO
treatment can reverse this damage to dendritic spine formation.
To mimic the damage done by placental insufficiency in humans, an established rat
model of systemic prenatal hypoxia-ischemia was utilized. The transient hypoxic-ischemic
insult was delivered on embryonic day 18 (E18) by uterine artery occlusion. This is the
time period that corresponds to the onset of synaptogenesis and dendrite development. On
postnatal day 44 (P44) the rat brains were removed and stained with Golgi-Cox
solution. Coronal sections that included the cortex and hippocampus were cut with a
vibrating microtome, and the sections were mounted. The sensory portion of the parietal
cortex and the CA1 and CA3 portions of the hippocampus were analyzed.
Neurons that have been analyzed thus far are only in the experimental and control groups without EPO
treatment. They show that there is a difference in not only the spine lengths, but also in the number of spines on
each neuron between the two groups. In the control groups the average number of spines has been 6.615 per 10
micron sections on a dendrite with a mean spine length of 1.734 +/-0.26 microns. The experimental groups show
an average number of spines of 5.2 per 10 micron sections on a dendrite with a mean spine length of 2.299 +/-
0.463 microns. In conclusion, the group that experienced placental insufficiency had less spines developed on
their dendrites and spines lengths were longer and therefore less developed. Only preliminary results have been
established, and more neurons from both the control and experimental groups must be analyzed. The next step is
to analyze control and experimental neurons from groups treated with EPO to evaluate whether EPO is able to
recover any of the damage.
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