are inventors on a provisional patent (PCT ref. no. SD2017-181-2PCT) filed by UC, San Diego that is titled "Assessing risk of de novo mutations in males".

Objective Polymicrogyria (PMG) is a malformation of cortical development characterized by formation of an excessive number of small gyri. Sixty percent to 85% of patients with PMG have epilepsy that is refractory to medication, but surgical options are usually limited. We characterize a cohort of patient with polymicrogyria who underwent epilepsy surgery and document seizure outcomes. Methods A retrospective study of all patients with PMG who underwent epilepsy surgery (focal seizure foci resection and/or hemispherectomy) at our center was performed by review of all clinical data related to their treatment. Results We identified 12 patients (7 males and 5 female) with mean age of 18 (ranging from 3 months to 44 years) at time of surgery. Mean age at seizure onset was 8 years, with the majority (83%) having childhood onset. Six patients had focal, five had multifocal, and one patient had diffuse PMG. Perisylvian PMG was the most common pattern seen on magnetic resonance imaging (MRI). Eight patients had other cortical malformations including hemimegalencephaly and cortical dysplasia. Scalp electroencephalography (EEG) often showed diffuse epileptic discharges that poorly lateralized but were focal on intracranial electrocorticography (ECoG). Eight patients underwent seizure foci resection and four underwent hemispherectomy. Mean follow-up was 7 years (ranging from one to 19 years). Six patients (50%) were seizure-free at last follow-up. One patient had rare seizures (Engel class II). Three patients were Engel class III, having either decreased seizure frequency or severity, and two patients were Engel class IV. Gross total resection of the PMG cortex trended toward good seizure control. Significance Our study shows that even in patients with extensive or bilateral PMG malformations, some may still be good candidates for surgery because the epileptogenic zone may involve only a portion of the malformation. Intracranial ECoG can provide additional localizing information compared to scalp EEG in guiding resection of epileptogenic foci.

BACKGROUND Hypoxic preconditioning (HPc) protects the neonatal brain in the setting of hypoxia-ischemia (HI). The mechanisms of protection may depend on activation of hypoxia inducible factor (HIF-1α). The present study sought to clarify the role of HIF-1α after HPc and HI. METHODS To induce HPc, HIF-1α knockout and wildtype mice were exposed to hypoxia at postnatal day 6. At day 7, the mice underwent HI. Brain injury was determined by histology. HIF-1α, downstream targets, and markers of cell death were measured by Western blot. RESULTS HPc protected the wildtype brain compared to wildtype without HPc, but did not protect the HIF-1α knockout brain. In wildtype, HIF-1α increased after hypoxia and after HI, but not with HPc. The HIF-1α knockout showed no change in HIF-1α after hypoxia, HI, or HPc/HI. After HI, spectrin 145/150 was higher in HIF-1α knockout, but after HPc/HI, it was higher in wildtype. LAMP2 was higher in wildtype early after HI, but not later. After HPc/HI, LAMP2 was higher in HIF-1α knockout. CONCLUSION These results indicate that HIF-1α is necessary for HPc protection in the neonatal brain, and may affect cell death after HI. Different death and repair mechanisms depend on the timing of HPc.

The Src family kinases (SFKs) Src and Fyn are implicated in hypoxic–ischemic (HI) injury in the developing brain. However, it is unclear how these particular SFKs contribute to brain injury. Using neuron-specific Fyn overexpressing (OE) mice, we investigated the role of neuronal Fyn in neonatal brain HI. Wild type (WT) and Fyn OE mice were subjected to HI using the Vannucci model at postnatal day 7. Brains were scored five days later for evaluation of damage using cresyl violet and iron staining. Western blotting with postsynaptic density (PSD)-associated synaptic membrane proteins and co-immunoprecipitation with cortical lysates were performed at various time points after HI to determine NMDA receptor tyrosine phosphorylation and Fyn kinase activity. Fyn OE mice had significantly higher mortality and brain injury compared to their WT littermates. Neuronal Fyn overexpression led to sustained NR2A and NR2B tyrosine phosphorylation and enhanced NR2B phosphorylation at tyrosine (Y) 1472 and Y1252 in synaptic membranes. These early changes correlated with higher calpain activity 24 h after HI in Fyn OE mice relative to WT animals. Our findings suggest a role for Fyn kinase in neuronal death after neonatal HI, possibly via up-regulation of NMDA receptor tyrosine phosphorylation.

The Src family kinases (SFKs) are nonreceptor protein tyrosine kinases that are implicated in many normal and pathological processes in the nervous system. The SFKs Fyn, Src, Yes, Lyn, and Lck are expressed in the brain. This review will focus on Fyn, as Fyn mutant mice have striking phenotypes in the brain and Fyn has been shown to be involved in ischemic brain injury in adult rodents and, with our work, in neonatal animals. An understanding of Fyn's role in neurodevelopment and disease will allow researchers to target pathological pathways while preserving protective ones.

Background and Purpose The NR2B subunit of the NMDA receptor (NMDAR) is phosphorylated by the Src family kinase Fyn in brain, with tyrosine (Y) 1472 as the major phosphorylation site. While Y1472 phosphrylation is important for synaptic plasticity, it is unknown whether it is involved in NMDAR-mediated excitotoxicity in neonatal brain hypoxiaischemia (HI). This study was designed to elucidate the specific role of Y1472 phosphorylation of NR2B in neonatal HI in vivo and in NMDA-mediated neuronal death in vitro. Methods Neonatal mice with a knock-in mutation of Y1472 to phenylalanine (YF-KI) and their wildtype (WT) littermates were subjected to HI using the Vannucci model. Brains were scored five days later for damage using cresyl violet and iron staining. Western blotting and immunoprecipitation were performed to determine NR2B tyrosine phosphorylation. Expression of NADPH oxidase subunits and superoxide production were measured in vivo. NMDA-induced calcium response, superoxide formation and cell death were evaluated in primary cortical neurons. Results After neonatal HI, YF-KI mice have reduced expression of NADPH oxidase subunit gp91phox and p47phox and superoxide production, lower activity of proteases implicated in necrotic and apoptotic cell death, and less brain damage compared to the WT mice. In vitro, YF-KI mutation diminishes superoxide generation in response to NMDA without effect on calcium accumulation; and inhibits NMDA and glutamate-induced cell death. Conclusions Upregulation of NR2B phosphorylation at Y1472 following neonatal HI is involved in superoxide-mediated oxidative stress and contributes to brain injury.

Activation of NMDA receptors (NMDAR) is associated with divergent downstream signaling leading to neuronal survival or death that may be regulated in part by whether the receptor is located synaptically or extrasynaptically. Distinct activation of the MAP kinases ERK and p38 by synaptic and extrasynaptic NMDAR is one of the mechanisms underlying these differences. We have recently shown that the Src family kinases (SFKs) play an important role in neonatal hypoxic-ischemic brain injury by regulating NMDAR phosphorylation. In this study, we characterized the distribution of NMDAR, SFKs and MAP kinases in synaptic and extrasynaptic membrane locations in the postnatal day 7 and adult mouse cortex. We found that the NMDAR, SFKs and phospho-NR2B were predominantly at synapses, whereas striatal-enriched protein tyrosine phosphatase (STEP) and its substrates ERK and p38 were much more concentrated extrasynaptically. NR1/NR2B was the main subunit at extrasynaptic membrane with concomitant NR2B phosphorylation at tyrosine (Y) 1336 in the immature brain. STEP expression increased, while p38 decreased with development in the extrasynaptic membrane. These results suggest that SFKs and STEP are poised to differentially regulate NMDAR-mediated signaling pathways due to their distinct subcellular localization, and thus may contribute to the age-specific differences seen in vulnerability, pathology and consequences of hypoxic–ischemic brain injury.

Proteomics of the synapses and postsynaptic densities (PSDs) have provided a deep understanding of protein composition and signal networks in the adult brain, which underlie neuronal plasticity and neurodegenerative or psychiatric disorders. However, there is a paucity of knowledge about the architecture and organization of PSDs in the immature brain, and how it is modified by brain injury in an early developing stage. Mass spectrometry (MS)-based proteomic analysis was performed on PSDs prepared from cortices of postnatal day 9 naïve mice or pups which had suffered hypoxic-ischemic (HI) brain injury. 512 proteins of different functional groups were identified from PSDs collected 1 h after HI injury, among which 60 have not been reported previously. Seven newly identified proteins involved in neural development were highlighted. HI injury increased the yield of PSDs at early time points upon reperfusion, and multiple proteins were recruited into PSDs following the insult. Quantitative analysis was performed using spectral counting, and proteins whose relative expression was more than 50% up- or downregulated compared to the sham animals 1 h after HI insult were reported. Validation with Western blotting demonstrated changes in expression and phosphorylation of the N-methyl-D-aspartate receptor, activation of a series of postsynaptic protein kinases and dysregulation of scaffold and adaptor proteins in response to neonatal HI insult. This work, along with other recent studies of synaptic protein profiling in the immature brain, builds a foundation for future investigation on the molecular mechanisms underlying developing plasticity. Furthermore, it provides insights into the biochemical changes of PSDs following early brain hypoxia-ischemia, which is helpful for understanding not only the injury mechanisms, but also the process of repair or replenishment of neuronal circuits during recovery from brain damage.