Intranasal phenylephrine, an alpha‐1 adrenergic agonist, causes vasoconstriction of the nasal mucosa and is used to reduce bleeding associated with nasotracheal intubation or endoscopic sinus surgery. The purpose of this study was to describe the hemodynamic effects associated with plasma phenylephrine concentrations following topical intranasal administration of 0.25% and 0.5% phenylephrine in children.

Early postnatal blockade of NMDA receptors by phencyclidine (PCP) causes cortical apoptosis in animals. This is associated with the development of schizophrenia-like behaviors in rats later in life. Recent studies show that the mechanism involves a loss of neurotrophic support from the phosphoinositol-3 kinase/Akt pathway, which is normally maintained by synaptic NMDA receptor activation. Here we report that activation of dopamine D1 receptors (D1R) with dihydrexidine (DHX) prevents PCP-induced neurotoxicity in cortical neurons by enhancing the efficacy of NMDAergic synapses. DHX increases serine phosphorylation of the NR1 subunit through protein kinase A activation and tyrosine phosphorylation of the NR2B subunit via Src kinase. DHX enhances recruitment of NR1 and NR2B, but not NR2A, into synapses. DHX also facilitated the synaptic response in cortical slices and this was blocked by an NR2B antagonist. DHX pre-treatment of rat pups prior to PCP on postnatal days 7, 9 and 11 inhibited PCP-induced caspase-3 activation on PN11 and deficits in pre-pulse inhibition of acoustic startle measured on PN 26-28. In summary, these data demonstrate that PCP-induced deficits in NMDA receptor function, neurotoxicity and subsequent behavioral deficits may be prevented by D1R activation in the cortex and further, it is suggested that D1R activation may be beneficial in treating schizophrenia.

The mechanism underlying phencyclidine (PCP)-induced apoptosis in perinatal rats and the development of schizophrenia-like behaviors is incompletely understood. We used antagonists for N-methyl-d-aspartate (NMDA) receptor subunit NR2A- and NR2B-containing NMDA receptor to test the hypothesis that the behavioral and apoptotic effects of PCP are mediated by blockade of NR1/NR2A-containing receptors, rather than NR1/NR2B-containing receptors. Sprague-Dawley rats were treated on PN7, PN9, and PN11 with PCP (10 mg/kg), PEAQX (NR2A-preferring antagonist; 10, 20, or 40 mg/kg), or ifenprodil (selective NR2B antagonist; 1, 5, or 10 mg/kg) and sacrificed for measurement of caspase-3 activity (an index of apoptosis) or allowed to age and tested for locomotor sensitization to PCP challenge on PN28-PN35. PCP or PEAQX on PN7, PN9, and PN11 markedly elevated caspase-3 activity in the cortex; ifenprodil showed no effect. Striatal apoptosis was evident only after subchronic treatment with a high dose of PEAQX (20 mg/kg). Animals treated with PCP or PEAQX on PN7, PN9, and PN11 showed a sensitized locomotor response to PCP challenge on PN28-PN35. Ifenprodil treatment had no effect on either measure. Therefore, PCP blockade of cortical NR1/NR2A, rather than NR1/NR2B, appears to be responsible for PCP-induced apoptosis and the development of long-lasting behavioral deficits.

Phencyclidine is an N-methyl d-aspartate receptor (NMDAR) blocker that has been reported to induce neuronal apoptosis during development and schizophrenia-like behaviors in rats later in life. Brain-derived neurotrophic factor (BDNF) has been shown to prevent neuronal death caused by NMDAR blockade, but the precise mechanism is unknown. This study examined the role of the phosphatidylinositol-3 kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK) pathways in BDNF protection of PCP-induced apoptosis in corticostriatal organotypic cultures. It was observed that BDNF inhibited PCP-induced apoptosis in a concentration-dependent fashion. BDNF effectively prevented PCP-induced inhibition of the ERK and PI-3K/Akt pathways and suppressed GSK-3β activation. Blockade of either PI-3K/Akt or ERK activation abolished BDNF protection. Western blot analysis revealed that the PI-3K inhibitor LY294002 prevented the stimulating effect of BDNF on the PI-3K/Akt pathway, but had no effect on the ERK pathway. Similarly, the ERK inhibitor PD98059 prevented the stimulating effect of BDNF on the ERK pathway, but not the PI-3K/Akt pathway. Co-application of LY294002 and PD98059 had no additional effect on BDNF-evoked activation of Akt or ERK. However, concurrent exposure to PD98059 and LY294002 caused much greater inhibition of BDNF-evoked phosphorylation of GSK-3β at serine 9 than did LY294002 alone. Finally, either BDNF or GSK-3β inhibition prevented PCP-induced suppression of cyclic-AMP response element binding protein (CREB) phosphorylation. These data demonstrate that the protective effect of BDNF against PCP-induced apoptosis is mediated by parallel activation of the PI-3K/Akt and ERK pathways, most likely involves inhibition of GSK-3β and activation of CREB.

NMDA receptor blockade by phencyclidine (PCP) in neonatal rats causes wide‐spread apoptosis and certain schizophrenia‐like behavioral abnormalities later in life. Disruption of BDNF signaling may play a role in the development of schizophrenia and mediate the neurotoxic effects of NMDAR blockers. Therefore, this study was designed to test the potential protective effects of BDNF on PCP‐induced apoptosis in corticostriatal slice culture and to explore the possible mechanisms. We observed that BDNF prevented PCP‐induced capase‐3 activation and DNA fragmentation dose‐dependently. The Trk B receptor inhibitor, K252a, abolished the protective effects of BDNF, indicating that BDNF acts through TrkB receptors. Further investigation of the downstream signaling transduction of TrkB activation revealed that BDNF prevented the dephosphorylation of Akt, GSK‐3β and ERK induced by PCP. In addition, pharmacological blockade of these pathways with either the MEK inhibitor PD98059 or the PI‐3K/Akt pathway inhibitors, LY294002 and Akt inhibitor V, completely abolished the protective effects of BDNF. Finally, the observation that the inhibitors of either the PI‐3K/Akt or the MEK/ERK pathway selectively prevented the stimulating effects of BDNF on the two pathways suggests that the two pathways are independently involved in the neuroprotection against PCP toxicity afforded by BDNF. Supported by DA‐02073.

We sought to determine the relationship between phencyclidine (PCP)-induced alterations in behavior and NMDAR expression in the cortex by examining the effect of anti-schizophrenic drug treatment on both. Sprague-Dawley rat pups were pretreated with risperidone or olanzapine prior to treatment with PCP on postnatal day 7 (PN7) or sub-chronically on PN7, 9, and 11. Pre-pulse inhibition (PPI) of acoustic startle was measured on PN24-26 and following a challenge dose of 4 mg/kg PCP. locomotor activity was measured on PN28-35. PCP treatment on PN7 did not cause a deficit in Pill, but did cause locomotor sensitization. This was prevented by both antipsychotics. PCP treatment on PN7 caused an up-regulation of NR1 and NR2B, which was not affected by either anti-schizophrenic drug. PCP treatment on PN7, 9, and 11 caused a deficit in PPI and a sensitized locomotor response to PCP challenge as well as an up-regulation of NR1 and NR2A, all of which were prevented by both atypical anti-schizophrenic drugs. These data support the hypothesis that sub-chronic, but not single injection PCP treatment in developing rats results in behavioral alterations that are sensitive to antipsychotic drugs and these behavioral changes observed could be related to up-regulation of cortical NR1/NR2A receptors. (c) 2008 Elsevier Inc. All rights reserved.

Abstract This paper documents changing patterns of concentrated poverty in nonmetro areas. Data from the Decennial U.S. Census Summary Files show that poverty rates—both overall and for children—declined more rapidly in nonmetro than metro counties in the 1990s. The 1990s also brought large reductions in the number of high‐poverty nonmetro counties and declines in the share of rural people, including rural poor people, who were living in them. This suggests that America's rural pockets of poverty may be “drying up” and that spatial inequality in nonmetro America declined over the 1990s, at least at the county level. On a less optimistic note, concentrated poverty among rural minorities remains exceptionally high. Roughly one‐half of all rural blacks and one‐third of rural Hispanics live in poor counties. Poor minorities are even more highly concentrated in poor areas. Rural children—especially rural minority children—have poverty rates well above national and nonmetro rates, the concentration of rural minority children is often extreme (i.e., over 80% lived in high‐poverty counties), and the number of nonmetro counties with high levels of persistent child poverty remains high (over 600 counties). Rural poor children may be more disadvantaged than ever, especially if measured by their lack of access to opportunities and divergence with children living elsewhere. Patterns of poverty among rural children—who often grow up to be poor adults— suggest that recent declines in concentrated rural poverty may be short‐lived.

N-methyl-D-aspartate (NMDA) receptor antagonists such as phencyclidine (PCP) can induce positive and negative symptoms of schizophrenia in humans and related effects in rodents. PCP treatment of developing rats induces apoptotic neurodegeneration and behavioral deficits later in life that mimic some symptoms of schizophrenia. The precise mechanism of PCP-induced neural degeneration is unknown. This study used selective antagonists, siRNA, and Western analysis to investigate the role of the Akt-glycogen synthase kinase-3β (GSK-3β) pathway in PCP-induced neuronal apoptosis in both neuronal culture and postnatal day 7 rats. PCP administration in vivo and in vitro reduced the phosphorylation of AktSer427 and GSK-3βSer9, decreasing Akt activity and increasing GSK-3β activity. The alteration of Akt-GSK-3β signaling parallels the temporal profile of caspase-3 activation by PCP. Reducing GSK-3β activity by application of selective inhibitors or depletion of GSK-3β by siRNA attenuates caspase-3 activity and blocks PCP-induced neurotoxicity. Moreover, increasing synaptic strength by either activation of L-type calcium channels with BAY K8644 or potentiation of synaptic NMDA receptors with either a low concentration of NMDA or bicuculline plus 4-aminopyridine completely blocks PCP-induced cell death by increasing Akt phosphorylation. These neuroprotective effects are associated with activation of phosphoinositide-3-kinase-Akt signaling, and to a lesser extent, the MAPK signaling pathway. Overall, these data suggest that PCP-induced hypofunction of synaptic NMDA receptors impairs the Akt-GSK-3β cascade, which is necessary for neuronal survival during development, and that interference with this cascade by PCP or natural factors may contribute to neural pathologies, perhaps including schizophrenia.

Transient postnatal NMDA receptor blockade by phencyclidine (PCP), ketamine, or MK-801 induces developmental neuroapoptosis and adult behavioral deficits, which resemble abnormal human behaviors typically present in schizophrenia. This study tested the hypothesis that PCP-induced developmental apoptosis causes a specific deficit of GABAergic interneurons containing parvalbumin (PV), calretinin (CR), or calbindin (CB). Young adult (PND56) rats that were given a single dose of PCP (10 mg/kg) on PND7 exhibited no densitometric change of either CR or CB neurons in any brain region studied, but demonstrated a selective deficit of PV-containing neurons in the superficial layers (II-IV) of the primary somatosensory (S1), motor (M), and retrosplenial cortices, but not in the striatum (CPu) or hippocampus. Further, CR and CB neurons, which were expressed at the time of PCP administration, showed no colocalization with cellular markers of apoptosis (terminal dUTP nick-end labeling (TUNEL) of broken DNA or cleaved caspase-3), indicating that CR- and CB-containing neurons were protected from the toxic effect of PCP and survived into adulthood. This suggests that the deletion of PV neurons occurred during development, but cleaved caspase-3 showed no colocalization with BrdU, a specific marker of S-phase proliferation. These data suggest that the loss of PV-containing neurons was not due to an effect of PCP on proliferating neurons, but rather an effect on post-mitotic neurons. The developmental dependence and neuronal specificity of this effect of PCP provides further evidence that this model may be valuable in exploring the pathophysiology of schizophrenia.

Phencyclidine (PCP)-induced neurotoxicity in neonatal rats has been used as a model of schizophrenia. We previously observed that caspase-3 dependent cell death induced by PCP in corticostriatal slice cultures could be blocked by lithium (Li+). Here, we tested the hypothesis that this protective effect was mediated by brain-derived neurotrophic factor (BDNF). We observed that BDNF (50 ng/ml) prevented PCP-induced capase-3 activation and DNA fragmentation as measured by TUNEL. Further, the Trk B receptor inhibitor, K252a (0.5 μM), and BDNF neutralizing antibody (40 ng/ml) abolished the protective effects of Li+. Western blot analysis revealed a temporary inhibition of extracellular-regulated kinase (ERK) after PCP treatment, which was also prevented by Li+. Co-application of 30 μM PD98059 (MEK inhibitor) attenuated the protective effects of Li+. Next, we investigated the downstream signaling pathways of BDNF in vivo. Treatment of postnatal day 7 pups with PCP (10 mg/kg) resulted in temporary dephosphorylation of AKT/PKB, GSK-3β and ERK, in the frontal cortex, striatum, and hippocampus. In summary, these data suggest that Li+ protection against PCP is mediated by BDNF and ERK activation. Furthermore, the correlation of results from in vitro and in vivo preparations suggests this slice model is suitable for the mechanistic study of the neurotoxic effects of PCP in vivo. Supported by MH-63871 and DA-02073.

Neurodegeneration induced by the NMDA receptor antagonist, phencyclidine (PCP), has been used to model the pathogenesis of schizophrenia in the developing rat. Acute and sub-chronic administration of PCP in perinatal rats results in different patterns of neurodegeneration. The potential role of an alteration in the membrane expression of NMDA receptors in PCP-induced degeneration is unknown. Acute PCP treatment on postnatal day 7 increased membrane levels of both NMDA receptor subunit 1 (NR1) and NMDA receptor subunit 2B (NR2B) proteins in the frontal cortex; conversely, NR1 and NR2B protein levels in the endoplasmic reticulum fraction were decreased. Acute PCP administration also resulted in increased membrane cortical protein levels of post-synaptic density-95, as well as the activation of calpain, which paralleled the observed increase in membrane expression of NR1 and NR2B. Further, administration of the calpain inhibitor, MDL28170, prevented PCP-induced up-regulation of NR1 and NR2B. On the other hand, sub-chronic PCP treatment on postnatal days 7, 9 and 11 caused an increase in NR1 and NR2A expression, which was accompanied by an increase in both NR1 and NR2A in the endoplasmic reticulum fraction. Sub-chronic PCP administration did not alter levels of postsynaptic density-95 and had no effect on activation of calpain. These data suggest that increased trafficking accounts for up-regulation of cortical NR1/NR2B subunits following acute PCP administration, while increased protein synthesis likely accounts for the increased expression of NR1/NR2A following sub-chronic PCP treatment of the developing rat. These results are discussed in the context of the differential neuro-degeneration caused by acute and subchronic PCP administration in the developing rat brain.

This study determined the role of caspase-3 in phencyclidine (PCP)-induced neurodegeneration in postnatal rats. PCP administration to postnatal day 7 rats induced a dose-dependent increase in caspase-3 enzymatic activity in frontal cortex, striatum, and hippocampus. Enzymatic activation was present at 4 h, peaked between 6 and 12 h, and disappeared by 24 h. Further, cleaved caspase-3-immunoreactive neurons were detected as early as 2 h in the cortex, and were found throughout the brain, including, in addition, the thalamus and striatum. Within the cingulate, frontal, parietal, and retrosplenial cortices, immunoreactivity was specific for layers II–IV (especially layer II). Neurons positive for both silver staining and terminal deoxynucleotidyl transferase biotin-d-UTP nick-end labeling (TUNEL) were found in the same brain regions and subregions. Double labeling experiments confirmed that cleaved caspase-3 and TUNEL were coexpressed in many neurons in all brain regions and subregions studied. Temporal studies revealed that procaspase-3 cleavage preceded TUNEL staining by about 3 h, with many neurons being positive for both caspase-3 and TUNEL 9 h after PCP treatment. In organotypic corticostriatal slices, PCP caused a concentration- and time-dependent cleavage of procaspase-3 that was also colocalized with TUNEL staining in layers II–IV of the parietal cortex. Caspase-3 activation again preceded PCP-induced DNA damage assessed by TUNEL. PCP-induced neuronal death in vitro as measured by TUNEL staining was blocked 85% by Ac-AAVALLPAVLLALLAPDEVD-CHO, a cell-permeable selective caspase-3 inhibitor. These data demonstrate that caspase-3 activation plays a necessary role in the regionally selective neuronal death induced by PCP in the developing rat brain.

This study presents basin-wide anthropogenic CO 2 inventory estimates for the Indian Ocean based on measurements from the World Ocean Circulation Experiment/Joint Global Ocean Flux Study global survey. These estimates employed slightly modified AC* and time series techniques originally proposed by Gruber et al. [ 1996] and Wallace [ 1995], respectively. Together, the two methods yield the total oceanic anthropogenic CO 2 and the carbon increase over the past 2 decades. The highest concentrations and the deepest penetrations of anthropogenic carbon are associated with the Subtropical Convergence at around 30 ø to 40øS. With both techniques, the lowest anthropogenic CO 2 column inventories are observed south of 50øS. The total anthropogenic CO 2 inventory north of 35øS was 13.6+2 Pg C in 1995. The inventory increase since GEOSECS (Geochemical Ocean Sections Program) was 4.1+1 Pg C for the same area. Approximately 6.7+1 Pg C are stored in the Indian sector of the Southern Ocean, giving a total Indian Ocean inventory of 20.3 +3 Pg C for 1995. These estimates are compared to anthropogenic CO 2 inventories estimated by the Princeton ocean biogeochemistry model. The model predicts an Indian Ocean sink north of 35øS that is only 0.61-0.68 times the results presented here; while the Southern Ocean sink is nearly 2.6 times higher than the measurement-based estimate. These results clearly identify areas in the models that need further examination and provide a good baseline for future studies of the anthropogenic inven-

Schizophrenia is a severe psychiatric disorder whose etiology is unknown; however, disruptions in glutamatergic and dopaminergic transmission may play a role. The NMDAR antagonist, phencyclidine (PCP), has been shown to mimic both the positive and negative symptoms of the disease and is widely used in animal studies as a model of schizophrenia. PCP administration results in increased locomotor activity and deficits in pre-pulse inhibition (PPI) of acoustic startle. Locomotor sensitization is thought to model the positive symptoms while deficits in PPI are correlated to the negative symptoms of the disease. Sprague-Dawley rat pups were treated with saline or PCP (10 mg/kg) on postnatal day (PN) 7, 9, and 11 and PPI was measured on PN24-25. On PN28-35 animals were administered a challenge dose of 4 mg/kg PCP and locomotor activity was measured. PCP administration resulted in a deficit in PPI as well as locomotor sensitization. Additional experiments tested the effect of pretreatment with the typical antipsychotic haloperidol or the atypical antipsychotics, olanzapine and risperidone. Haloperidol (0.1 mg/kg), olanzapine (1 mg/kg), and risperidone (0.25 mg/kg) were able to prevent the deficits in PPI caused by PCP administration. Risperidone (0.25 mg/kg) was also able to prevent locomotor sensitization in animals administered PCP. Future experiments will further investigate the role of haloperidol and olanzapine as well as selective DA and 5-HT antagonists in this behavioral model of schizophrenia in order to determine the mechanism of protection by typical and atypical antipsychotics. Supported by DA-07287, MH-63871 and Eli Lilly and Co.

Activating mutations of the genes for NRAS and BRAF, components of the p44/42 mitogen-activated protein kinase (MAPK) pathway, are common findings in melanoma. Recent evidence in several nonmelanoma cell systems supports the regulation of the inducible nitric oxide synthase (iNOS) gene by this pathway. On the basis of our data showing that melanoma iNOS expression predicts shortened patient survival, we formulated the hypothesis that activating mutations of NRAS or BRAF, which lead to constitutive activation of the p44/42 MAPK pathway, drive iNOS expression in human melanoma. In the present study, we have shown that inhibition of melanoma iNOS activity by S-methylisothiourea leads to decreased cell proliferation, confirming the importance of iNOS activity for melanoma cell growth. Regulation of melanoma iNOS expression by the p44/42 MAPK pathway was demonstrated by inhibition of the pathway by U0126, and by BRAF RNA interference. To explore this regulatory pathway in human tissue, 20 melanoma tumors were examined for NRAS and BRAF mutations, immunohistochemical evidence of ERK phosphorylation, and iNOS expression. A significant association was found among these three features. We conclude that in human melanoma, activating mutations of NRAS and BRAF drive constitutive iNOS expression and, implicitly, nitric oxide production, contributing to the poor survival of these patients.

Central neuropathic pain (CNP) is an important problem following spinal cord injury (SCI), because it severely affects the quality of life of SCI patients. As in the patient population, the majority of rats develop significant allodynia (CNP rats) after moderate SCI. However, about 10% of SCI rats do not develop allodynia, or develop significantly less allodynia than CNP rats (non‐CNP rats). To identify transcriptional changes underlying CNP development after SCI, we used Affymetrix DNA microarrays and RNAs extracted from the spinal cords of CNP and non‐CNP rats. DNA microarry analysis showed significantly increased expression of a number of genes associated with inflammation and astrocytic activation in the spinal cords of rats that developed CNP. For example, mRNA levels of glial fibrilary acidic protein (GFAP) and Aquaporin 4 (AQP4) significantly increased in CNP rats. We also found that GFAP, S100β and AQP4 protein elevation persisted for at least 9 months throughout contused spinal cords, consistent with the chronic nature of CNP. Thus, we hypothesize that CNP development results, in part, from dysfunctional, chronically “over‐activated” astrocytes. Although, it has been shown that activated astrocytes are associated with peripheral neuropathic pain, this has not previously been demonstrated in CNP after SCI.