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Several lines of evidence implicate BDNF in the pathophysiology of psychiatric illness. BDNF polymorphisms have also been associated with the risk of schizophrenia and mood disorders. We therefore investigated whether levels of (pro)BDNF and receptor proteins, TrkB and p75, are altered in hippocampus in schizophrenia and mood disorder and whether polymorphisms in each gene influenced protein expression. Formalin-fixed paraffin-embedded hippocampal sections from subjects with schizophrenia, major depressive disorder (MDD), bipolar disorder (BPD) and non-psychiatric controls were obtained from the Stanley Foundation Neuropathology Consortium. (pro)BDNF, TrkB(T1) and p75 protein densities were quantified by immunoautoradiography and DNA extracted from each subject was used to determine the effect of genotype on protein expression. In MDD, reductions in (pro)BDNF were seen in all layers of the right but not the left hippocampus with no changes in the dentate gyrus. The pattern was similar but less marked for BPD. In addition, BPD but not MDD patients, had bilateral reductions in p75 in hippocampal layers but not in dentate gyrus. No changes in TrkB(T1) density were seen in any diagnosis. These findings suggest MDD and BPD may share impairment in (pro)BDNF expression. However, BPD may involve impairments of both (pro)BDNF and p75 receptor, whereas MDD may involve impaired (pro)BDNF alone. Moreover, the lateralisation of changes may indicate a role of asymmetry in vulnerability to MDD. Hippocampal (pro)BDNF and receptor levels were also affected by genotype, suggesting that allelic variations are important in the hippocampal abnormalities seen in these psychiatric disorders.

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In Clayoquot Sound, British Columbia, gray whales (Escbricbtius robustus) forage for pelagic, hyperbenthic, and benthic invertebrates. Prey types were collected near feeding whales and at sites where no whales were observed to ascertain whales' diets and to describe prey populations and distributions. Characteristics of prey that are examined include species composition, density, biomass, and size. Whales foraged for mysids, Holmesimysis sculpta being the most abundant species collected. Whales foraged near concentrated patches of porcelain crab zoeal larvae, composed primarily of Pacbycbeles rudis, 21-294 times the average density and biomass normally collected. Arnphipod biomass, composed primarily of Ampelisca agassizi and A. careyi, was 160 2 150 g/m2 where whales foraged. Larger amphipods, rather than higher density, resulted in higher amphipod biomass between years. Whales foraged where there was a high proportion (61%) of amphipods >6 mm in length.Whales initially foraged for amphipods along the 20-m depth contour line; amphipod biomass was best developed and least variable at depths between 16 and 20 m.