Behavioural and neural correlates of operant conditioning in Lymnaea stagnalis : role of previous experience during development /

The freshwater mollusc Lymnaea stagnalis was utilized in this study to further the understanding of how network properties change as a result of associative learning, and to determine whether or not this plasticity is dependent on previous experience during development. The respiratory and neural correlates of operant conditioning were first determined in normally reared Lymnaea. The same procedure was then applied to differentially reared Lymnaea, that is, animals that had never experienced aerial respiration during their development. The aim was to determine whether these animals would demonstrate the same responses to the training paradigm. In normally reared animals, a behavioural reduction in aerial respiration was accompanied by numerous changes within the neural network. Specifically, I provide evidence of changes at the level of the respiratory central pattern generator and the motor output. In the differentially reared animals, there was little behavioural data to suggest learning and memory. There were, however, significant differences in the network parameters, similar to those observed in normally reared animals. This demonstrated an effect of operant conditioning on differentially reared animals. In this thesis, I have identified additional correlates of operant conditioning in normally reared animals and provide evidence of associative learning in differentially reared animals. I conclude plasticity is not dependent on previous experience, but is rather ontogenetically programmed within the neural network.

Metabolite changes during Riesling icewine fermentation when yeast micronutrients are used /

Icewine is an intensely s\veet dessert \vine fermented from the juice of naturally frozen grapes. Icewine fermentation poses many challenges such as failure to reach desired ethanol levels and production of high levels of volatile acidity in the fonn of acetic acid. This study investigated the impact of micronutrient addition (GO-FERM® and NATSTEP®) during the rehydration stage of the commercial \vine yeast Saccharomyces cerevisiae KI-VIII6 during Ice\vine fermentation. Sterile-filtered and unfiltered Riesling Ice\vine juice was inoculated \vith yeast rehydrated under four different conditions: in water only; with GO-FERM®; with NATSTEP®; or the combination of both micronutrient products in the rehydration water. Using sterile-filtered Icewine juice, yeast rehydration had a positive impact of reducing the rate of acetic acid produced as a function of sugar consumed, reducing the ratio of acetic acid/ethanol and reducing the ratio of acetic acid/glycerol. In the sterile-filtered fermentation, yeast rehydrated with micronutrients generated 9-times less acetic acid per gram of sugar in the first 48 hours compared to yeast rehydrated only \vith water and resulted in a 17% reduction in acetic acid in the final \vine \vhen normalized to sugar consumed. However, the sterile-filtered fermentations likely became stuck due to the overc1arification of the juice as evidenced from the low sugar consumption (117 gIL) that could not be completely overcome by the micronutrient treatments (144 gIL sugar consumed) to reach a target ethanol of IO%v/v. Contrary to \vhat \vas observed in the sterile-filtered treatements, using unfiltered Ice\vine juice, yeast micronutrient addition had no significant impact of reducing the rate of acetic acid produced as a function of sugar consumed, reducing the ratio of acetic acid/ethanol and reducing the ratio of acetic acid/glycerol. However, in the unfiltered fermentation, micronutrient addition during yeast rehydration caused a reduction in the acetic acid produced as a function of sugar consumed up to 150 giL sugar consumed.. In contrast to the sterile-filtered fermentations, the unfiltered fermentations did not become stuck as evidenced from the higher sugar consumption (l47-174g1L). The largest effects of micronutrient addition are evident in the first two days of both sterile and unfiltered fermentations.

Anxiety and learning / response behaviour in the context of intellectual problem solving by young children

Twenty-eight grade four students were ca.tegorized as either high or low anxious subjects as per Gillis' Child Anxiety Scale (a self-report general measure). In determining impulsivity in their response tendencies, via Kagan's Ma.tching Familiar Figures Test, a significant difference between the two groups was not found to exist. Training procedures (verbal labelling plus rehearsal strategies) were introduced in modification of their learning behaviour on a visual sequential memory task. Significantly more reflective memory recall behaviour was noted by both groups as a result. Furthermore, transfer of the reflective quality of this learning strategy produced significantly less impulsive response behaviour for high and low anxious subjects with respect to response latency and for low anxious subjects with respect to response accuracy.

Action of octopamine and tyramine on muscles of Drosophila melanogaster larvae

Octopamine (OA) and tyramine (TA) play important roles in homeostatic mechanisms, behavior, and modulation of neuromuscular junctions in arthropods. However, direct actions of these amines on muscle force production that are distinct from effects at the neuromuscular synapse have not been well studied. We utilize the technical benefits of the Drosophila larval preparation to distinguish the effects of OA and TA on the neuromuscular synapse from their effects on contractility of muscle cells. In contrast to the slight and often insignificant effects of TA, the action of OA was profound across all metrics assessed. We demonstrate that exogenous OA application decreases the input resistance of larval muscle fibers, increases the amplitude of excitatory junction potentials (EJPs), augments contraction force and duration, and at higher concentrations (10−5 and 10−4 M) affects muscle cells 12 and 13 more than muscle cells 6 and 7. Similarly, OA increases the force of synaptically driven contractions in a cell-specific manner. Moreover, such augmentation of contractile force persisted during direct muscle depolarization concurrent with synaptic block. OA elicited an even more profound effect on basal tonus. Application of 10−5 M OA increased synaptically driven contractions by ∼1.1 mN but gave rise to a 28-mN increase in basal tonus in the absence of synaptic activation. Augmentation of basal tonus exceeded any physiological stimulation paradigm and can potentially be explained by changes in intramuscular protein mechanics. Thus we provide evidence for independent but complementary effects of OA on chemical synapses and muscle contractility.

By-Law no. 12

A by-law begins: "It was then moved by R.S. Kinner and Seconded by George Barnes that by Law No. 12 be read. Whereas by Identure bearing date thirteenth day of August A.D. 1873 made between one George Barnes of the first part thereof and Andrew S. Kinner and Charles Robert Murray of the second part thereof which said Identure was duly registered in the Registry Office for Lands for the said County of Lincoln on the 14th day of August A.D. 1880 in Book 4 for the Township of Louth as No. 1534 the said George Barnes granted and conveyed the Lands and premises therein described to the said Andrew S. Kinner and Charles Robert Murray and their heirs and assigns as joint tenants and not as tenants as common upon the trusts and for the purposes therein expressed. And Whereas the said Andrew S. Kinner died on about the 13th day of June 1877 A.D. without having made any appointment under the provisions of the said in part recited Identure.."

Public Instrument of Protest

Public Instrument of Protest (1 double-sided handwritten page) by William W. Gillvery and the North West Company against Angus W. Gillis for breaking his agreement with the company, March 26, 1800.