There is a large sex difference in the prevalence of attention deficit disorder; yet, little is known about sex differences in prefrontal attention circuitry. We investigated sex differences in the developmental nicotinic excitation of corticothalamic layer VI neurons, which play an important role in attention. Using whole cell recording in prefrontal brain slices, we examined the inward currents elicited by nicotinic stimulation in rodents. We found a prominent sex difference in the currents during the first postnatal month when males had significantly greater α4β2* nicotinic currents. Immunohistochemical analysis of α4YFP mice revealed no sex difference in the pattern or proportion of YFP-positive neurons in layer VI. Further electrophysiological experiments revealed that progesterone is able to rapidly and significantly suppress nicotinic currents in layer VI neurons. This is the first illustration at a cellular level that prefrontal attention circuitry is differently excited by nicotinic stimulation in males and females during development.

The feasibility of using real-time functional magnetic resonance imaging (fMRI) feedback regarding the level of activation in rostromedial prefrontal cortex (rMPFC) to learn improved regulation of this brain area was examined in a group of 5 young adults. Subjects received real-time feedback from the target brain region while engaging in a blocked-design task involving alternating blocks of attempted up-regulation and down-regulation of the target brain region. A transient negative emotional state was induced prior to each scanning session. Subjects completed 6 scanning sessions (a pre-training session, 4 feedback sessions and a post-training session - no feedback was provided for pre and post-training sessions). The guideline strategy provided to subjects of engaging in emotional awareness during up-regulation and bodily awareness during down-regulation was found to consistently regulate the region in the pre-training session prior to the fMRI feedback sessions. This finding is in line with the previously proposed role of the rMPFC in emotional awareness. In contrast to previous real-time fMRI findings, greater recruitment of the region was observed in the pre-training session compared to the post-training session, with a non-significant negative trend observed across feedback sessions. These results suggest that there may be limitations to which the feedback techniques successfully employed for other brain regions extend to yet unexplored brain regions.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 4 uppsatser.

Thesis (M.A.)--University of Delaware, 2007. / Principal faculty advisor: Anna Klintsova, Dept. of Psychology. Includes bibliographical references.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 5 uppsatser.

Thesis (M.A.)--University of Delaware, 2008. / Principal faculty advisor: Jeffrey B. Rosen, Dept. of Psychology. Includes bibliographical references.

Thesis (M.Sc.)--University of Alberta, 2009. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Psychiatry. Title from pdf file main screen (viewed on October 31, 2009). Includes bibliographical references.

Thesis (M.A.)--York University, 2006. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 66-75). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR29554

Thesis (M.Sc.)--York University, 2008. Graduate Programme in Kinesiology and Health Science. / Typescript. Includes bibliographical references (leaves 69-81). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR51534

Memory formation and recall depend on a complex circuit that includes the hippocampus and associated cortical regions. The goal of this thesis was to understand how two of the cortical connections, the medial entorhinal cortex (MEC) and medial prefrontal cortex (mPFC), influence spatial and nonspatial activity in the hippocampus. Cells in the MEC exhibit prominent spatially selective activity and have been hypothesized to drive place representation in the hippocampus. In Experiment 1 the MEC was transiently inactivated using the inhibitory opsin ArchaerhodopsinT (ArchT), and simultaneous recordings from CA1 were made as rats ran on an elliptical track. In response to MEC disruption some cells in the hippocampus shifted the preferred location of activity, some changed firing rate and others were unaffected. The new representation that developed following MEC disruption remained stable despite the fact that inhibition was transient. If the MEC is the source of spatial activity in the hippocampus the activity would be either time-locked to periods of inhibition or unstable throughout the period of inconsistent input. These results show that the MEC guides spatial representation in the hippocampus but does not directly drive spatial firing. The mPFC is generally thought to guide behavior in response to contextual elements. Experiment 2 examined the interaction between the mPFC and the hippocampus as rats performed a contextual discrimination task. Recordings were made in CA1, and the mPFC was disrupted using ArchT during the odor sampling phase of the discrimination. As animals perform this task neurons in the hippocampus respond to a conjunction of odor and location which indicates an association of what and where information in the hippocampus. Optogenetic disruption of the mPFC led to a decrease in nonspatial representation. Individual cells showed lower levels of odor selectivity, but there was no change in the level of spatial representation. This indicates that the mPFC is important for determining how the hippocampus represents nonspatial information but does not alter the spatial representation. The results are discussed within a model of memory formation that includes binding spatial and nonspatial information in the hippocampus.