Synaptic reentry reinforcement based network model for long-term memory consolidation

The conversion of newly formed declarative memories into long-term memories is known to be dependent on the hippocampus. Recent experiments suggest that memory consolidation requires reactivation of the NMDA receptor in CA1 during the initial week(s) after training. This led to the hypothesis that the repeated post-learning reinforcement of synaptic modifications, termed synaptic reentry reinforcement (SRR), is essential for long-term memory consolidation and storage. Based on experimental observations, we have built a computational model to further illustrate and explore the effect of the SRR process on the formation of long-term memory. We show that SRR is capable of strengthening and maintaining memory traces despite inherent variability in the system due to such processes as the turnover of synaptic receptors and their associated signaling and structural proteins. Furthermore, we demonstrate that new rounds of synaptic modification triggered by memory reactivation, either during conscious recall or sleep, could lead to the selective consolidation of a subset of memory traces. Finally, we show why the SRR process in the hippocampus is required during the initial post-training weeks for synaptic reinforcement based memory consolidation in the cortex.     

Relationships between body image and depressive symptoms during postpartum in ethnically diverse,low income women

The aim of this study was to examine body image, depressive symptoms, and their interrelationship at post-delivery and at 6 weeks postpartum in a triethnic sample of low income new mothers. Data for this study were drawn from the Austin New Mothers Study. Participants were 76 Anglo/White, 72 African American, and 135 Hispanic new mothers who were participating in Medicaid, at least 18 years old, free of medical risk factors, and delivered at term. Body image was measured by the Body Cathexis Scale (BCS) and depressive symptoms by the Center for Epidemiologic Studies Depression Scale (CES-D). The leading areas of body dissatisfaction in postpartum were similar across ethnic groups. At 6 weeks postpartum Anglo women had the highest number of body image components perceived negatively, whereas African-American women had the least. In the overall sample, body image attitudes were significantly related to depressive symptoms in correlational (r's .19 to .34) and regression analyses. In addition, African American ethnicity was associated in regression analyses with higher depressive symptoms. Neither African American nor Hispanic ethnicity significantly moderated the relationship between body image attitudes and depressive symptoms in tests of interactions. Marital/partnered status and income level were related to depressive symptoms at both time points. In addition, being a woman with a parity of II was associated with higher depressive symptoms at 6 weeks postpartum. Although addition of these personal variables increased the percent of variance accounted for, body image attitudes continued to be significant predictors of depressive symptoms.     

Delayed presentation of traumatic arterial vasospasm

Traumatic arterial vasospasm with no surrounding anatomic damage is a rare finding. Delayed presentation of arterial vasospasm several days from the inciting event is also rare. However, when the diagnosis of arterial vasospasm is considered, evaluation and treatment must be initiated promptly to avoid prolonged ischemia to the extremity. We present an 11-year-old female who presented with a delayed presentation of arterial vasospasm, and also review the literature.     

Harvesting of the latissimus dorsi muscle: A small animal model for seroma formation

A common complication of soft tissue dissection and muscle harvesting is seroma formation. In order to manage and understand the formation of seromas, we developed a small animal model for seromas in the Sprague Dawley rat. Skin flaps and subcutaneous tissue were elevated and the latissimus dorsi muscle was harvested in 20 animals. Eighteen of the 20 rats (90%) formed clinically significant seromas. Sixteen animals had associated skin flap necrosis and 12 required serial drainage for recurrent seromas. At necropsy, gross capsular formation occurred in all animals who developed seromas. Microscopically, a fibrous capsule enveloping the seroma was seen associated with a focal chronic inflammatory cell infiltrate. We conclude: (1) Elevation of the latissimus dorsi muscle in the rat is a reliable and practical animal model for seroma formation; (2) Sequelae of clinically significant seromas are often as severe as skin flap necrosis; (3) An inflammatory reaction may be associated with seromas. © 1995 Wiley-Liss, Inc.     

Does levodopa alter depression and psychopathology in Parkinsonism patients?

Twenty-seven Parkinsonism patients and 31 controls, matched for age and verbal IQ, were tested on an objectively scored personality test (Minnesota Multiphasic Personality Inventory) at the beginning of the patients' levodopa therapy and three months later. Patients, but not the controls, were retested after 15 months of levodopa treatment. The patients, all of whom were intact intellectually, obtained MMPI scores indicating moderate depression before beginning levodopa treatment. There was no test evidence to indicate that levodopa significantly increased or decreased the amount of depression in the patients after three or 15 months of levodopa. The patient group, however, significantly increased their Index of Psychopathology (Ip) score after 15 months of levodopa but not after three months.     

Dorsal root ganglion neurones in culture: a model system for identifying novel analgesic targets?

Ion channels represent attractive targets in the development of novel analgesics for the treatment of pain. Dorsal root ganglion (DRG) neurones in culture can share characteristics with nociceptors in vivo and are frequently used to investigate the ion channels that underlie the transduction of noxious stimuli into electrical activity during sensory processing. In this article, I describe the methods used to prepare cultures of DRG neurones including the procedures for the dissection, enzymatic dissociation and plating. The criteria used to identify putative nociceptors in vitro are reviewed and using the M-current as an example I highlight how potential analgesic targets can be identified by combining the use of the voltage clamp technique with the use of selective pharmacological agents.