Role of the Calcium Plateau in the Neuronal Injury and Behavioral Morbidities Following Organophosphate Intoxication

Organophosphate (OP) chemicals include nerve agents and pesticides, and there is a growing concern of OP based chemical attacks against civilians. Current antidotes are essential in limiting immediate mortality associated with OP exposure. However, further research is needed to identify molecular mechanisms underlying long-term neurological deficits following survival of OP toxicity in order to develop effective therapeutics. We have developed rat survival models of OP induced status epilepticus (SE) that mimic chronic mortality and morbidity following OP intoxication. We have observed significant elevations in hippocampal calcium levels after OP SE that persisted for weeks following initial survival. Drugs inhibiting intracellular calcium-induced calcium release such as dantrolene, levetiracetam, and carisbamate lowered OP-SE mediated protracted calcium elevations. Given the critical role of calcium signaling in modulating behavior and cell-death mechanisms, drugs targeted at preventing the development of the calcium plateau could enhance neuroprotection, help reduce morbidity and improve outcome following survival of OP SE

Determination of interaction effects in expectations for post-event information on memory for items in a service encounter

Our minds are not a blank canvas onto which experiences leave their independent and indelible impression. Consumers, therefore, would rarely enter a service encounter without prior knowledge to guide their expectations. The importance of prior knowledge – in the form of schemas – while acknowledged in the study of post-event misinformation effects on memory has received limited attention. Outside of studies investigating misinformation effects, the literature indicates that inconsistency between our expectations and what we experience, improves recall accuracy. Whether this effect translates into reduced susceptibility to misinformation effects and that schema consistency increases susceptibility, is unclear. The main contribution of this thesis is the demonstration that consistency between schema and the experience, and its interaction with encoding goals, changes a person’s susceptibility to misinformation and their subsequent store quality perceptions. The effects of encoding goals – whether someone is trying to form an impression or remember the details of their experience – while used in previous misinformation studies, has not been previously investigated. To investigate the effects of schema consistency and encoding goals on misinformation acceptance, and the subsequent impact of misinformation acceptance on store quality perceptions, a three-way between participant design was undertaken using a café service encounter as the context. The three factors – independent variables – and their levels included in the study were schema consistency (consistent/ inconsistent), encoding goal (impression/ recall) and post-event information (misinformation/ neutral). Results from the study showed that misinformation effects are most likely when people are paying less attention to the service environment. The explanation provided in the study is that when there is a match between what people expect and what they experience they pay less attention to the details of the experience, which results in less diagnostic information encoded into memory. If, however, they were paying attention due to an inconsistency, the information would be attended and result in reduced misinformation acceptance. Where a person was instructed to try and remember the details of their experience rather than form an impression, they paid greater attention to detail than those who were forming an impression. When their expectations were not met in an experience, subsequent exposure to misinformation causes these people to accurately recall their original experience and escape the effect of misinformation. Significant results were also observed for changes to store quality perceptions, revealing that consumers who accept the misinformation have store quality perceptions that reflect its inclusion. Also observed was an interaction with the initial expectations that meant merchandise quality perceptions improved when a person’s memory for the experience was consistent with their original expectations, and lower when inconsistent

Appetitive Operant Conditioning in Mice: Heritability and Dissociability of Training Stages

To study the heritability of different training stages of appetitive operant conditioning, we carried out behavioral screening of 5 standard inbred mouse strains, 28 recombinant-inbred (BxD) mouse lines and their progenitor strains C57BL/6J and DBA/2J. We also computed correlations between successive training stages to study whether learning deficits at an advanced stage of operant conditioning may be dissociated from normal performance in preceding phases of training. The training consisted of two phases: an operant nose poking (NP) phase, in which mice learned to collect a sucrose pellet from a food magazine by NP, and an operant lever press and NP phase, in which mice had to execute a sequence of these two actions to collect a food pellet. As a measure of magazine oriented exploration, we also studied the nose poke entries in the food magazine during the intertrial intervals at the beginning of the first session of the nose poke training phase. We found significantly heritable components in initial magazine checking behavior, operant NP and lever press–NP. Performance levels in these phases were positively correlated, but several individual strains were identified that showed poor lever press–NP while performing well in preceding training stages. Quantitative trait loci mapping revealed suggestive likelihood ratio statistic peaks for initial magazine checking behavior and lever press–NP. These findings indicate that consecutive stages toward more complex operant behavior show significant heritable components, as well as dissociability between stages in specific mouse strains. These heritable components may reside in different chromosomal areas

Abnormal hippocampal theta and gamma hypersynchrony produces network and spike timing disturbances in the Fmr1-KO mouse model of Fragile X syndrome

Contains fulltext : 191465.pdf (publisher's version ) (Open Access

Ca2: It's about time-and episodes

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Editorial overview: Large-scale recording technology: Scaling up neuroscience

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Population coding dynamics and layer-resolved oscillation in the CA1 region of the hippocampus

Data from Guardamagna et al. Biorxiv https://www.biorxiv.org/content/10.1101/2021.12.22.473863v

Local sensory cues and place cell directionality: Additional evidence of prospective coding in the hippocampus

Contains fulltext : 201424.pdf (publisher's version ) (Open Access