Rescue of synaptic plasticity and spatial learning deficits in the hippocampus of Homer1 knockout mice by recombinant Adeno-associated viral gene delivery of Homer1c

Homer1 belongs to a family of scaffolding proteins that interact with various post-synaptic density proteins including group I metabotropic glutamate receptors (mGluR1/5). Previous research in our laboratory implicates the Homer1c isoform in spatial learning. Homer1 knockout mice (H1-KO) display cognitive impairments, but their synaptic plasticity properties have not been described. Here, we investigated the role of Homer1 in long-term potentiation (LTP) in the hippocampal CA1 region of H1-KO mice in vitro. We found that late-phase LTP elicited by high frequency stimulation (HFS) was impaired, and that the induction and maintenance of theta burst stimulation (TBS) LTP were reduced in H1-KO. To test the hypothesis that Homer1c was sufficient to rescue these LTP deficits, we delivered Homer1c to the hippocampus of H1-KO using recombinant adeno-associated virus (rAAV). We found that rAAV-Homer1c rescued HFS and TBS-LTP in H1-KO animals. Next, we tested whether the LTP rescue by Homer1c was occurring via mGluR1/5. A selective mGluR5 antagonist, but not an mGluR1 antagonist, blocked the Homer1c-induced recovery of late-LTP, suggesting that Homer1c mediates functional effects on plasticity via mGluR5. To investigate the role of Homer1c in spatial learning, we injected rAAV-Homer1c to the hippocampus of H1-KO. We found that rAAV-Homer1c significantly improved H1-KO performance in the Radial Arm Water Maze. These results point to a significant role for Homer1c in synaptic plasticity and learning.     

Development and initial validation of the Adolescent Responses to Body Dissatisfaction Measure

One community sample (N = 607) of youths generated self-reported responses to body dissatisfaction, from which the Adolescent Responses to Body Dissatisfaction (ARBD) inventory was constructed. A 2nd, similar sample (N = 830) completed this measure as well as measures of coping, body dissatisfaction, body mass index, depressive symptoms, and disordered eating behaviors. Evidence of 6 ARBD factors emerged: Self-Acceptance, Compensatory Thinking, Diet/Exercise, Anxious Responding, Appearance Strategies, and Social Comparison. Subscales based on these factors provided evidence of convergent, discriminant, construct, and incremental validity. Sex and ethnic differences were also evident. Adolescents' use of Self-Acceptance and Compensatory Thinking strategies appeared to attenuate the relation between body dissatisfaction and psychopathology, whereas use of Diet/Exercise and Anxious Responding appeared to exacerbate this relation, especially in adolescents who were not overweight. The ARBD provides a window into potentially healthy and unhealthy ways in which adolescents cope with body dissatisfaction. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

The Princess and the Penis: A Post Postmodern Queer-y Tale

This paper explores whether postmodern gender theory can fully account for how a “cis” gender (gender and biology match) therapist works with a “trans” gender patient in a relational way. Inspiring contemporary queer theory exists courtesy of experts in the field, but how does a nongender expert deal with the complicated enactments that occur when patient transitions her gender from female to male and then decides to become pregnant? It is suggested that this case may more accurately represent an example of a post-postmodern analysis, in that it holds the dialectic of constructed gender within the realities of a social system that remains deeply gender binaried.     

A self-referential default brain state: patterns of coherence,power, and eLORETA sources during eyes-closed rest and Transcendental Meditation practice

Activation of a default mode network (DMN) including frontal and parietal midline structures varies with cognitive load, being more active during low-load tasks and less active during high-load tasks requiring executive control. Meditation practices entail various degrees of cognitive control. Thus, DMN activation patterns could give insight into the nature of meditation practices. This 10-week random assignment study compared theta2, alpha1, alpha2, beta1, beta2 and gamma EEG coherence, power, and eLORETA cortical sources during eyes-closed rest and Transcendental Meditation (TM) practice in 38 male and female college students, average age 23.7 years. Significant brainwave differences were seen between groups. Compared to eyes-closed rest, TM practice led to higher alpha1 frontal log-power, and lower beta1 and gamma frontal and parietal log-power; higher frontal and parietal alpha1 interhemispheric coherence and higher frontal and frontal-central beta2 intrahemispheric coherence. eLORETA analysis identified sources of alpha1 activity in midline cortical regions that overlapped with the DMN. Greater activation in areas that overlap the DMN during TM practice suggests that meditation practice may lead to a foundational or ‘ground’ state of cerebral functioning that may underlie eyes-closed rest and more focused cognitive processes.     

Unequally masked: Indexing differences in the perceptual salience of "unseen" facial expressions

Two experiments investigated the degree to which different facial expressions, when backwardly masked by neutral faces, are blocked from different levels of perceptual access as indexed by explicit (self-reported) awareness, forced-identification performance, and stimulus sensitivity in a signal detection paradigm. Results indicate that a 16.67 ms target-mask stimulus onset asynchrony (SOA) is insufficient to reliably block either the simple detection or the forced-identification of backwardly masked expressions. This finding holds even for participants who deny possessing any explicit awareness of the masked images whatsoever. Furthermore, "unseen" happy faces are less effectively masked by neutral expressions than are unseen angry or neutral faces, an observation that might also extend to other affective expressions (e.g., fear). These results expand upon previous findings (Esteves & Öhman, 1993) and provide new information about the multitude of factors that may be operating in research that involves backwardly masked facial expressions.     

Representation and the Intrapsychic: Cartesian Barriers to Empathic Contact

This paper argues for a radical relational perspective that explicitly challenges the notion of the intrapsychic and the related Cartesian assumptions of representationalism. Conceptual tools derived from the school of embodied cognition provide an alternative theoretical language that depicts a new understanding of experience as an emergent and distributed phenomenon of a dialogic communicative system. Clinical vignettes illustrate how this new ontology of experience promotes a therapeutic ambience that dissolves the barriers to empathic contact imposed by the retention of representational modes of thought.     

Between Dolev and Dummett: Some Comments on ‘Antirealism,Presentism and Bivalence’

Abstract

It is well known that, according to some, philosophical reflection on zombies (i.e. bodies without minds) poses a problem for physicalism. But what about ghosts, i.e., minds without bodies? Does philosophical reflection on them pose a problem for physicalism? Descartes, of course, thought so, and lately rumours have been surfacing that has was right after all, that ghosts pose a problem for both a priori and a posteriori physicalism, and for any kind of physicalism in between. This paper argues that physicalists have nothing to fear from ghosts, since the central consideration employed to motivate ghostly arguments against physicalism – i.e. that ghosts are conceivable – is false: ghosts aren’t conceivable.     

My people,right or wrong? Minimal group membership disrupts preschoolers’ selective trust

When preschoolers decide to trust one speaker over another, how does group membership influence their tracking of speaker reliability? In Experiment 1, 4-year-olds were assigned to arbitrary groups of no social significance (0055 and 0170) and asked to endorse novel object labels provided by two ingroup members, one of whom was reliable and the second of whom was unreliable. Children selectively trusted the more reliable informant. In Experiment 2, we asked whether ingroup status or reliability would determine children's choices and found that 4-year-olds failed to trust reliable outgroup members over unreliable ingroup members (or vice versa). Experiment 3 showed that the failure of trust in Experiment 2 was not due to the mere inclusion of both ingroup and outgroup members: children presented with a control paradigm in which the ingroup members were reliable trusted reliable ingroup members over unreliable outgroup members. Children's use of reliability as an indicator of future credibility therefore appears disrupted when outgroup status and reliability are in conflict, even when group membership is arbitrary.