Identifying effective treatments for Alzheimer's disease (AD) has proven challenging and has instigated a recent shift in AD research focus towards the earliest disease-initiating cellular mechanisms. A key insight has been an increase in soluble Aβ oligomers in early AD that is causally linked to neuronal and circuit hyperexcitability. However, other accumulating AD-related peptides and proteins, including those derived from the same amyloid precursor protein, such as Aη or sAPPα, and autonomously, such as tau, exhibit surprising opposing effects on circuit dynamics. We propose that the effects of these on neuronal circuits has profound implications for our understanding of disease complexity and heterogeneity, and the development of personalized diagnostic and therapeutic strategies in AD. Here, we highlight important peptide-specific mechanisms of dynamic pathological disequilibrium of cellular and circuit activity in AD and discuss approaches in which these may be further understood, and theoretically and experimentally leveraged, to elucidate AD pathophysiology.

We have demonstrated that neonatal exposure to selective serotonin reuptake inhibitors has lasting effects on behavior and serotonergic neurons in Long Evans rats. Hyperserotoninemia and altered sensory processing are reported in autistic spectrum disorders (ASD). We hypothesized that early life exposure to SSRIs alters sensory processing, disrupts responses to novelty and impairs social interactions in a manner similar to that observed in ASD. Male and female Long-Evans rat pups were administered citalopram, buproprion, fluoxetine, or saline from postnatal day (P) 8 to 21. Rats were tested for response to a novel tone before weaning (P25). Later, rats were tested 2× for response to a novel object (P39), and to a novel conspecific (P78, P101). In addition, rats were assessed for juvenile play behaviors (P32–P34) and later, we assessed sexual response to an estrus female in male rats (P153–184). Antidepressant exposure increased freezing after tone, diminished novel object exploration and reduced conspecific interaction up to 3× compared to saline exposed rats. Juvenile play was profoundly reduced in antidepressant-exposed males when compared to saline exposed groups. Exposure to the SSRIs, but not bupropion disrupted male sexual behaviors. Moreover, specific male responses to female proceptive behaviors were disrupted in SSRI, but not bupropion exposed rats. We conclude that neonatal exposure to antidepressants in rats results in sensory and social abnormalities that parallel many of those reported in ASD.

HELLP syndrome is a disorder associated with serious maternal morbidity and mortality. Distinguishing HELLP from other pregnancy related disorders is often challenging and may result in delay of treatment. Differential diagnoses include acute fatty liver of pregnancy, thrombotic thrombocytopenic purpura, antiphospholipid syndrome, and hemolytic uremic syndrome, and are reviewed in this chapter. While there is not any current treatment for HELLP, the mainstay of treatment involves maternal stabilization and timely delivery. Various treatment strategies have been attempted to help decrease the morbidity and mortality of HELLP, including the maternal use of corticosteroids. The authors review the studies and controversies surrounding the maternal use of corticosteroids, plasma exchange, and low molecular weight heparin for the treatment of HELLP, as well as the role of the complement system in HELLP. Further large, well-designed, randomized controlled trials are needed to address the role corticosteroids may play in the treatment of women with HELLP and to help improve maternal and fetal outcomes.