Role of antidepressants in fetal synapse formation in Autism Spectrum Disorders

Autism is a genetically complex neurodevelopmental disorder in which patients exhibit social deficits in both verbal and non-verbal forms of communication and display restricted and repetitive behaviors. Approximately 1 in 68 children are diagnosed with Autism in the United States². The prevalence of Autism in North Carolina is even greater where 1 in 58 children are diagnosed³. Autism is thought to be influenced by both genetic and environmental factors. Complex interactions between these factors make the creation of therapeutic treatments difficult to achieve. One environmental factor that is being studied in relation to Autism is the anti-depressant Fluoxetine. Fetal exposure to Fluoxetine through maternal ingestion of the drug or consumption of drinking water where the drug is present is thought to interrupt normal fetal brain development. Fluoxetine has previously been show to increase dendritic spine formation , the main location of excitatory synapse development. However , the exact mechanism that causes this dysregulation of the actin cytoskeleton is not fully understood. Post-mortem samples from individuals with Autism also display increased dendritic spine levels. We hypothesize that Fluoxetine acts through the Rac1 pathway to increase dendritic spine density. To examine the impact of Fluoxetine on fetal synapse formation human cortical organoids , or 'mini-brains' , were created to recapitulate the second trimester fetal brain. Once the 'mini-brains' reached the appropriate time point in development they were treated either acutely with Fluoxetine , chronically with Fluoxetine , with the Rac1 inhibitor NSC23766 or a combination of Fluoxetine and NSC23766. After 90 days in culture , the 'mini-brains' were harvested , fixed , cryosectioned and stained for pre- and post-synaptic markers. Using ImageJ excitatory synapse density and morphology was analyzed. It was determined that Fluoxetine caused enlargement of synapses that were irregular in shape. The effects of Fluoxetine on synapse formation were reduced when combined with the Rac1 inhibitor NSC23766. In addition to examining excitatory synapse formation , the effects of Fluoxetine and NSC23766 on electrical signal transmission was also observed using micro-electrode technology. Both Fluoxetine and NSC23766 were shown to decrease neuronal activity

Fundamental Social Motives and Their Effect On Food Selection in Undergraduate Students

Social motives affect multiple aspects of our daily lives with and without conscious awareness of these effects. Fundamental social motives play an important role in impacting how people think, make decisions and act. This research was designed to investigate how situational factors and fundamental social motives interact to affect food selection via an in-person experiment. Participants in this research were randomly assigned to complete the experiment in the presence of a same or opposite sex partner. Based on whether they were assigned to a “public” or “private” condition, they either disclosed to their partner what they would order at a restaurant, or they kept this information private by reporting the same information via a confidential form on their computer instead of to their partner. Following the food selection task, participants completed a series of questionnaires designed to measure social motives and tendencies to respond in particular ways during social interactions. Finally, they were asked to rate their partner based on factors such as friendliness and attractiveness. It was predicted that opposite-sex partners who are primarily or exclusively heterosexual and not involved in a committed romantic relationship will order fewer calorie meals in the presence of an opposite sex partner who they deem to be more attractive if they are publicly reporting their order. Meal choices of heterosexual same-sex partners are not expected to be influenced by perceptions of partners

Export production in the New-Zealand region since the last glacial maximum

Increased export production (EP) in the Subantarctic Zone (SAZ) of the Southern Ocean due to iron fertilisation has been proposed as a key mechanism for explaining carbon drawdown during the last glacial maximum (LGM). This work reconstructs marine EP since the LGM at four sites around New Zealand. For the first time in this region, 230-Thorium-normalised fluxes of biogenic opal, carbonate, excess barium, and organic carbon are presented. In Subtropical Waters and the SAZ, these flux variations show that EP has not changed markedly since the LGM. The only exception is a site currently north of the subtropical front. Here we suggest the subtropical front shifted over the core site between 18 and 12 ka, driving increased EP. To understand why EP remained mostly low and constant elsewhere, lithogenic fluxes at the four sites were measured to investigate changes in dust deposition. At all sites, lithogenic fluxes were greater during the LGM compared to the Holocene. The positive temporal correlation between the Antarctic dust record and lithogenic flux at a site in the Tasman Sea shows that regionally, increased dust deposition contributed to the high glacial lithogenic fluxes. Additionally, it is inferred that lithogenic material from erosion and glacier melting deposited on the Campbell Plateau during the deglaciation (18–12 ka). From these observations, it is proposed that even though increased glacial dust deposition may have relieved iron limitation within the SAZ around New Zealand, the availability of silicic acid limited diatom growth and thus any resultant increase in carbon export during the LGM. Therefore, silicic acid concentrations have remained low since the LGM. This result suggests that both silicic acid and iron co-limit EP in the SAZ around New Zealand, consistent with modern process studies. © 2017 Elsevier B.V

Export production in the New-Zealand region since the Last Glacial Maximum

Increased export production (EP) in the Subantarctic Zone (SAZ) of the Southern Ocean due to iron fertilisation has been proposed as a key mechanism for explaining carbon drawdown during the last glacial maximum (LGM). This work reconstructs marine EP since the LGM at four sites around New Zealand. For the first time in this region, 230-Thorium-normalised fluxes of biogenic opal, carbonate, excess barium, and organic carbon are presented. In Subtropical Waters and the SAZ, these flux variations show that EP has not changed markedly since the LGM. The only exception is a site currently north of the subtropical front. Here we suggest the subtropical front shifted over the core site between 18 and 12ka, driving increased EP. To understand why EP remained mostly low and constant elsewhere, lithogenic fluxes at the four sites were measured to investigate changes in dust deposition. At all sites, lithogenic fluxes were greater during the LGM compared to the Holocene. The positive temporal correlation between the Antarctic dust record and lithogenic flux at a site in the Tasman Sea shows that regionally, increased dust deposition contributed to the high glacial lithogenic fluxes. Additionally, it is inferred that lithogenic material from erosion and glacier melting deposited on the Campbell Plateau during the deglaciation (18–12ka). From these observations, it is proposed that even though increased glacial dust deposition may have relieved iron limitation within the SAZ around New Zealand, the availability of silicic acid limited diatom growth and thus any resultant increase in carbon export during the LGM. Therefore, silicic acid concentrations have remained low since the LGM. This result suggests that both silicic acid and iron co-limit EP in the SAZ around New Zealand, consistent with modern process studies