Influence of chronic corticosterone and glucocorticoid receptor antagonism in the amygdala on fear conditioning

Glucocorticoid receptor activation within the basolateral amygdala (BLA) during fear conditioning may mediate enhancement in rats chronically exposed to stress levels of corticosterone. Male Sprague-Dawley rats received corticosterone (400 microg/ml) in their drinking water (days 1-21), a manipulation that was previously shown to cause hippocampal CA3 dendritic retraction. Subsequently, rats were adapted to the fear conditioning chamber (day 22), then trained (day 23), and tested for conditioned fear to context and tone (day 25). Training consisted of two tone (20s) and footshock (500 ms, 0.25 mA) pairings. In Experiment 1, muscimol (4.4 nmol/0.5 microl/side), a GABAergic agonist, was microinfused to temporarily inactivate the BLA during training. Rats given chronic corticosterone showed enhanced freezing to context, but not tone, compared to vehicle-supplemented rats. Moreover, BLA inactivation impaired contextual and tone conditioning, regardless of corticosterone treatment. In Experiment 2, RU486 (0, 0.3, and 3.0 ng/0.2 microl/side) was infused on training day to antagonize glucocorticoid receptors in the BLA. Corticosterone treatment enhanced fear conditioning to context and tone when analyzed together, but not separately. Moreover, RU486 (3.0 ng/side) selectively exacerbated freezing to context in chronic corticosterone-exposed rats only, but failed to alter tone conditioning. Serum corticosterone levels were negatively correlated with contextual, not tone, conditioning. Altogether, these suggest that chronic corticosterone influences fear conditioning differently than chronic stress as shown previously. Moreover, chronic exposure to corticosteroids alters BLA functioning in a non-linear fashion and that contextual conditioning is influenced more than tone conditioning by chronic corticosterone and BLA glucocorticoid receptor stimulation.     

Searching for genetic influences on normal cognitive ageing

Differences in non-pathological cognitive ageing provide a useful case study for the opportunities and challenges facing cognitive science as it embraces advances in genetics. One replicated contributor to these differences is variability in the gene for apolipoprotein E. Genetic variations that influence neurodegenerative diseases, learning and memory, cardiovascular disease, and oxidative stress are among the candidates for influence on cognitive ageing differences. The area suffers the same problems as other domains in which quantitative trait loci are sought: uncertainty regarding the genetic architecture, unreliable strategies for candidate gene selection, lack of power leading to unreplicated findings, and poor characterisation of the phenotype. However, current progress in genetic knowledge, technology and informatics will contribute to progress in this important area.     

Phonological cues influence sex decisions about novel names

Investigations of first names in English have found that male and female names are distinguished by different phonological characteristics. This paper reports on findings that suggest native speakers of English rely on those same cues when making judgments about the sex of names with which they are unfamiliar. When presented with 40 novel, i.e., "invented" names, 25 university undergraduates judged one-syllable names and consonant-final names as male names; however, they judged two-syllable names and vowel-final names as female names. These findings indicate that certain phonological features are strong enough predictors of sex that they can be used to designate sex even with names never before encountered.     

Recollection rejection: false-memory editing in children and adults

Mechanisms for editing false events out of memory reports have fundamental implications for theories of false memory and for best practice in applied domains in which false reports must be minimized (e.g., forensic psychological interviews, sworn testimony). A mechanism posited in fuzzy-trace theory, recollection rejection, is considered. A process analysis of false-memory editing is presented, which assumes that false-but-gist-consistent events (e.g., the word SOFA, when the word COUCH was experienced) sometimes cue the retrieval of verbatim traces of the corresponding true events (COUCH), generating mismatches that counteract the high familiarity of false-but-gist-consistent events. Empirical support comes from 2 qualitative phenomena: recollective suppression of semantic false memory and inverted-U relations between retrieval time and semantic false memory. Further support comes from 2 quantitative methodologies: conjoint recognition and receiver operating characteristics. The analysis also predicts a novel false-memory phenomenon (erroneous recollection rejection), in which true events are inappropriately edited out of memory reports.     

LY354740, an mGlu2/3 receptor agonist as a novel approach to treat anxiety/stress

Metabotropic glutamate (mGlu) receptors, which include mGlu1-8 receptors, are a heterogeneous family of G-protein coupled receptors (GPCRs) that function to modulate neuronal excitation and plasticity via pre-synaptic, post-synaptic and glial mechanisms. Agonists for group II mGlu receptors (mGlu2 and mGlu3), such as LY354740, have been shown to suppress enhanced glutamatergic excitations in brain synapses known to be involved in the expression of fear/anxiety in animals and humans. Systemic administration of LY354740 increases open-arm time in the elevated plus maze in mice under conditions of moderate to severe stress, blocks the expression but not development of fear-potentiated startle in rats, prevents lactate-induced panic-like responses in panic-prone rats, and attenuates certain physiological, behavioral, and neurochemical consequences of acute stress in rodents. In these preclinical models, LY354740 does not produce the side-effects (e.g. sedation) that are associated with other anxiolytic agents such as benzodiazepines. Early clinical results with LY354740 have demonstrated safety and efficacy in a human anxiety model (panic provocation induced by CO2 challenge). Collectively, these data indicate mGlu2/3 receptor agonists such as LY354740 represent a promising new approach for treatment of anxiety and stress-related disorders in humans.     

Part-list reexposure and release of retrieval inhibition

In list-method directed forgetting, reexposure to forgotten List 1 items has been shown to reduce directed forgetting. proposed that reexposure to a few List 1 items only during a direct test of memory reinstates the entire List 1 episode. In the present experiments, part-list reexposure in the context of indirect as well as direct memory tests reduced directed forgetting. Directed forgetting was reduced when 50% or more of the items were reexposed, and was intact when only 25% were reexposed. Furthermore, part-list reexposure appeared to reinstate only reexposed items-not the entire List 1 episode.     

Health anxiety in children: development and psychometric properties of the Childhood Illness Attitude Scales

The course of severe anxiety surrounding health issues is unknown. The available literature suggests that adults who are overly anxious about health issues often interpret or misinterpret their bodily signs and symptoms to be indicative of a serious illness. The construct of health anxiety has not been examined in children and, to date, there has not been an instrument developed for this purpose. The Illness Attitude Scales is one of the most commonly used instruments for evaluating fears, beliefs, and attitudes that are associated with hypochondriasis and abnormal illness behaviour in adults. We sought to adapt the Illness Attitude Scales for use with children ages 8-15 years. The adapted Illness Attitude Scales was renamed the Childhood Illness Attitude Scales. Revisions to the adult version consisted of simplification of language, revision of Likert scale (i.e. 5-point to 3-point scale), and the addition of 7 questions to evaluate the role parents/guardians play in facilitating medical attention or treatment. Correlations between Childhood Illness Attitude Scales total scores and other self-report measures were supportive of the construct-related validity of the Childhood Illness Attitude Scales and suggested that it is a useful measure of health anxiety in school-age children. Practical and theoretical implications of the present results are discussed.     

Reliability and validity of the Parent-Child Relationship Inventory (PCRI): evidence from a longitudinal cross-informant investigation

Psychometric properties of the Parent-Child Relationship Inventory (PCRI) were examined using data collected from adolescents and their parents in the Fullerton Longitudinal Study. Results revealed acceptable internal consistency for most scales and moderate to high 1-year stability for all scales. Both parents' PCRI scores correlated with their views of family climate. Cross-informant concordance was pervasive and strong between mothers' PCRI scores and adolescents' perceptions of the parent-child relationship and family climate; however, convergence was not evident between fathers' and adolescents' reports. Additionally, poor performance was observed for the Autonomy scale. In conjunction with other research on parent-adolescent relationships, concerns are raised regarding the utility of scales to contrast mother-adolescent with father-adolescent relationships.