Group 5

The NO-cGMP-PKG Pathway Third step of activating PKG is critical for neuroprotective effects NF-kB Is a neuroprotective molecule that can protect developing neurons against cell-death They hypothesized that a neuroprotective protein whose activity depends on PKG-mediated phosphorylation is the effector molecule of the pathway

Activation of NF-kB requires phosphorylation of IkappaB -phosphorylation is critical for its survival promoting effects in neurons PKG can phosphorylate IkappaB cGMP drives PKG-induced phosphorylation of IkappaB They reasoned if NF-kB is the downstream of the NO-cGMP-PKG pathway then inhibition of NF-kB should abolish the neuroprotective effect of the pathway

Results Through experiments they confirmed NO-cGMP-PKG pathway signals its neuroprotective effects against alcohol via NF-kB -they found NF-kB inhibitor had no effect on alcohol induced cell death in cultures lacking nNOS -Alcohol induced cell death was higher in nNOS cultures than in wild type cultures, % cell death remained unchanged in the presence of NF-kB inhibitor Results showed the neuroprotective effect of the NO-cGMP-PKG pathway is mediated by NF-kB and that nNOS pathway depends upon NF-kB to exert its neuroprotective activity

Lack of nNOS function exacerbates alcohol’s neuroteratogenic effects in vivo Expose neonatal mice to acute doses of alcohol from 4 days to 9 days post natal to mimic binge drinking in pregnant women. Found that alcohol reduced neuronal survival in all brain regions, the losses being more severe in nNOS mice than in the wild type Lack of functional nNOS increases alcohol related neuronal loss and also lowers the dose of alcohol necessary to cause neuronal death **nNOS plays a key role in protecting neurons against alcohol toxicity in vivo

Mutation of nNOS makes the brain vulnerable to a single does of alcohol FASD is brought on by continued alcohol consumption during gestation A genetically susceptible fetus could be damaged by one does of alcohol In nNos- mice there was a significant neuronal loss while in the wild type there was no loss. Showed that in genetically susceptible fetus that a single does can greatly affect the brain and as a precaution women should avoid alcohol completely during pregnancy.

Lack on nNOS worsens behavioral deficits induced by developmental alcohol exposure Test if lack of functional nNOS gene can worse alcohol induced learning/ behavioral deficits in adulthood. Conducted the same experiment but then let the mice grow to adult hood. Used a open field activities, morris water maze and propulsive inhibition test to determine effects.

Lack on nNOS cont. Results were that the alcohol had a minimal effect on the wild type mice but greatly effected the nNOS -/- mice. Reinforces the findings on human conditions where children exposed in utero have learning and behavioral problems