Corticotropin-releasing hormone (CRH) is distributed throughout the brain and in peripheral sites but primarily is localized in the paraventricular nucleus of the hypothalamus. It is a "master" stress hormone that is responsible for the synthesis of proopiomelanocortin (POMC) in the anterior pituitary gland. Behaviorally active peptide hormones, including adrenocorticotropin hormone (ACTH) and B-endorphin, are liberated from POMC by enzymes to activate critical processes during stress. CRH is not detectable in the circulation even during extreme stress. However, during human pregnancy, the human placenta expresses the gene for CRH (pCRH) resulting in detectable levels in maternal plasma that increases 20- to 40-fold over the course of gestation. Placental CRH is identical to CRH of hypothalamic origin in size, structure, immunoreactivity, and bioactivity. However, unlike the negative feedback between adrenal cortisol and hypothalamic CRH, cortisol stimulates the synthesis and release of pCRH. The bidirectional release of pCRH into maternal and fetal compartments is associated with regulating the timing of delivery, remodeling the fetal nervous system, and influencing developmental trajectories. Fetal exposure to pCRH during early and late gestation is associated with unique patterns of cortical thinning in school-age children. Placental CRH is elevated in response to physical and behavioral stress and may be an integrative marker of early adversity.

Previous studies demonstrated that stimuli synchronized with systolic and diastolic phases of the pulse pressure wave enhanced the visual event related potentials (ERPs) of the brain. The present study extended these observations to the auditory ERP in passive and attentional conditions. Pure tones were synchronized with systolic and diastolic phases of the cephalic and palmar arteries. During one condition, subjects were paid a bonus for reporting accurately the number of times they heard a tone (attention condition) and in a second condition they listened passively (non-attend). Stimuli synchronized with the diastolic phase, reliably produced augmentation of the N1 component across all conditions. The N2 component was smaller in the right hemisphere of attentive subjects when stimulation was synchronized with diastole. These results were discussed in the context of the cognitive psychophysiology proposed by Picton and Hillyard (1974).

Until the cause of Alzheimer's disease (AD) is discovered, programs designed to extend functioning are critical to confront the projected increase in cases and the escalating cost of patient management. A program of rehabilitation designed to improve memory was developed that focussed on effortful and involuntary processes of memory and amplification of attention. Eleven patients with probable AD and their spouses enrolled in a four week course to improve their ability to recall names and faces, and recent events. Rehearsal and stimulation of "deep" processing significantly improved the ability of AD patients to recall name-face relationships. Recall of television content was significantly improved with procedures requiring patients to expend effort while they watched. A significant event technique that provoked "emotional" memories and produced "flashbulb" memories was the most effective procedure. Patients had nearly perfect recall for events during days of significant events. Generally the most effective techniques for improving memory involved manipulation of the environment and deemphasized memorization as a goal. © 1993 Taylor & Francis Group, LLC.

There is scant research on cognitive impairment in adults with learning disabilities (LD), even though at least some children with LD remain affected throughout adulthood. The present study was designed to examine several memory processes in adults with LD, including (a) recall with and without cueing, (b) item recognition, (c) proactive inhibition, and (d) semantically organized material. Twenty-one adults with learning disabilities (17 males and 4 females) between 18 and 33 years of age were compared with age matched controls (N = 88). There were two noteworthy findings: First, the adults with LD consistently overestimated their ability to remember lists of words; second, adults with LD were especially impaired in the test requiring termination of an exhaustive and thorough search for relevant material. The data suggest that level of expectation and organizational (structural) strategies are areas worthy of further investigation.

Brain and behavioral responses to infrequent but equiprobable, predictable (fixed) and unpredictable (random) targets were measured to test the hypothesis that a shift in focus from local to global (historical) events occurs across the life span. Memory of sequence was informative in the fixed condition because the occurrence of a target could be perfectly predicted. Recalling the sequences contributed to the development of global probability estimates in the random condition, but did not provide specific information about the occurrence of an event A highly significant advantage was evident in brain and behavioral responses only in young and middle-aged subjects to predictable targets (i.e., use of local information). Among elderly subjects, the event-related potentials and reaction times to predictable and random targets were indistinguishable. The relations of age and reaction time to P3 amplitude were topographically discrete and consistent with earlier literature. © 1993, Taylor & Francis Group, LLC. All rights reserved.

Fetal exposure of rats to beta-endorphin during the third trimester, either alone or with alpha-MSH, resulted in mild developmental delay and significant decreases in striatal dopamine receptor density (subsensitivity) persisting through maturity. The apparent paradoxical down-regulation of dopamine receptors in the presence of beta-endorphin was consistent with fetal exposure to dopamine receptor antagonists and synthesis inhibitors. These findings suggest biophysical properties of receptors which are unique to fetal development including loss of plasticity after exposure to antagonists. Permanent, down-regulation of the striatal dopamine system may be one mechanism underlying delayed development after fetal exposure to beta-endorphin which may accompany hypoxia. Even though there were no statistically significant differences between males and females in density of the dopamine receptor, the behavioral profile after peptide treatment was sexually demorphic. Behaviorally, female rats appeared sensitized to perinatal alpha-MSH and males to alpha-endorphin.