Noradrenergic modulatoins of odor learning and odor representation in the rat

How experience alters neuronal ensemble dynamics and how locus coeruleus-mediated norepinephrine release facilitates memory formation in the brain are the topics of this thesis. Here we employed a visualization technique, cellular compartment analysis of temporal activity by fluorescence in situ hybridization (catFISH), to assess activation patterns of neuronal ensembles in the olfactory bulb (OB) and anterior piriform cortex (aPC) to repeated odor inputs. Two associative learning models were used, early odor preference learning in rat pups and adult rat go-no-go odor discrimination learning. With catFISH of an immediate early gene, Arc, we showed that odor representation in the OB and aPC was sparse (~5-10%) and widely distributed. Odor associative learning enhanced the stability of the rewarded odor representation in the OB and aPC. The stable component, indexed by the overlap between the two ensembles activated by the rewarded odor at two time points, increased from ~25% to ~50% (p = 0.004-1.43E⁻4; Chapter 3 and 4). Adult odor discrimination learning promoted pattern separation between rewarded and unrewarded odor representations in the aPC. The overlap between rewarded and unrewarded odor representations reduced from ~25% to ~14% (p = 2.28E⁻⁵). However, learning an odor mixture as a rewarded odor increased the overlap of the component odor representations in the aPC from ~23% to ~44% (p = 0.010; Chapter 4). Blocking both α- and β-adrenoreceptors in the aPC prevented highly similar odor discrimination learning in adult rats, and reduced OB mitral and granule ensemble stability to the rewarded odor. Similar treatment in the OB only slowed odor discrimination learning. However, OB adrenoceptor blockade disrupted pattern separation and ensemble stability in the aPC when the rats demonstrated deficiency in discrimination (Chapter 5). In another project, the role of α₂-adrenoreceptors in the OB during early odor preference learning was studied. OB α2-adrenoceptor activation was necessary for odor learning in rat pups. α₂-adrenoceptor activation was additive with β-adrenoceptor mediated signalling to promote learning (Chapter 2). Together, these experiments suggest that odor representations are highly adaptive at the early stages of odor processing. The OB and aPC work in concert to support odor learning and top-down adrenergic input exerts a powerful modulation on both learning and odor representation.

The first time delivery of the first link learning series using Skype and YouTube

Introduction: This case study documented the experiences of informal and service providers who participated in the first time delivery of the First Link Learning Series from May–August 2013 in Newfoundland and Labrador. The aim of this study was to understand how informal caregivers of people with dementia experience this Internet mediated health resource, and how Skype and YouTube can be used as tools for the Alzheimer Society of Newfoundland and Labrador to effectively deliver the First Link Learning Series. Methods: Sources of data included key informant interviews (n=3), pre- study and post-study interviews with informal dementia caregivers (n=2), institutional documentation, field notes, and YouTube analytics. Framework Analysis was used to make meaning of the qualitative data, and descriptive statistics were used to report on quantitative outcomes. Findings: Between 3% and 17% of registered First Link clients attended the learning series sessions, however only two caregivers participated using Skype or YouTube. Framework Analysis revealed three shared themes: access, connection and privacy. Discussion: The themes helped to begin building theory about barriers and facilitators to Internet mediated health resources for informal dementia caregivers. Experiences of service providers using the Internet to support clients served to begin building a case for the appropriateness of these media. A modified version of Dansky et al.’s (2006) theoretical framework for evaluating E-Health research that situates the person/user in the model, helped guide discussion and propose future directions for the study of Internet based health resources for informal dementia caregivers.