Endogenous opioid peptides contribute to associative LTP in the hippocampal CA3 region

The medial and lateral perforant path projections to the hippocampal CA3 region display distinct mechanisms of long-term potentiation (LTP) induction, N-methyl-d-aspartate (NMDA) and opioid receptor dependent, respectively. However, medial and lateral perforant path projections to the CA3 region display associative LTP with coactivation, suggesting that while they differ in receptors involved in LTP induction they may share common downstream mechanisms of LTP induction. Here we address this interaction of LTP induction mechanisms by evaluating the contribution of opioid receptors to the induction of associative LTP among the medial and lateral perforant path projections to the CA3 region in vivo. Local application of the opioid receptor antagonists naloxone or Cys2-Tyr3-Orn5-Pen7-amide (CTOP) normally block induction of lateral perforant path-CA3 LTP. However, these opioid receptor antagonists failed to block associative LTP in lateral perforant path-CA3 synapses when it was induced by strong coactivation of the medial perforant pathway which displays NMDAR-dependent LTP. Thus strong activation of non-opioidergic afferents can substitute for the opioid receptor activation required for lateral perforant path LTP induction. Conversely, medial perforant path-CA3 associative LTP was blocked by opioid receptor antagonists when induced by strong coactivation of the opioidergic lateral perforant path. These data indicate endogenous opioid peptides contribute to associative LTP at coactive synapses when induced by strong coactivation of an opioidergic afferent system. These data further suggest that associative LTP induction is regulated by the receptor mechanisms of the strongly stimulated pathway. Thus, while medial and lateral perforant path synapses differ in their mechanisms of LTP induction, associative LTP at these synapses share common downstream mechanisms of induction.     

Assessing Couple Therapy as a Treatment for Individual Distress: When is Referral to Couple Therapy Contraindicated?

In order to better understand the effects of initial level of psychological disturbance on treatment outcome, a retrospective case control study of 95 couples who received couple therapy was conducted by sorting couples into one of four groups based on the degree of distress reported by individuals at intake: Neither distressed; both distressed; male distressed, female not distressed; female distressed, male not distressed. When partners started treatment with similar levels of disturbance both responded well in couple therapy. However, if the female reported clinical levels of disturbance at intake but her partner did not, outcome for the female was especially poor in contrast to outcomes for females receiving individual therapy. Clinically disturbed males showed significant gains in treatment even when their partners were not disturbed. These suggestive results argue for the possible value of conducting controlled studies of treatment assignment decisions that maximize positive outcomes.     

An evaluation of two differential reinforcement procedures with escape extinction to treat food refusal

Consumption of solids and liquids occurs as a chain of behaviors that may include accepting, swallowing, and retaining the food or drink. In the current investigation, we evaluated the relative effectiveness of differential reinforcement of the first behavior in the chain (acceptance) versus differential reinforcement for the terminal behavior in the chain (mouth clean). Three children who had been diagnosed with a feeding disorder participated. Acceptance remained at zero when differential reinforcement contingencies were implemented for acceptance or mouth clean. Acceptance and mouth clean increased for all 3 participants once escape extinction was added to the differential reinforcement procedures, independent of whether reinforcement was provided for acceptance or for mouth clean. Maintenance was observed in 2 children when escape extinction was removed from the treatment package. The mechanism by which consumption increased is discussed in relation to positive and negative reinforcement contingencies.     

Should Hispanic persons from different countries of origin be combined into one sample for analysis?

Hispanic respondents to 21 nationwide surveys were grouped on the basis of country of origin into Mexican Americans (n = 402), Puerto Ricans (n = 119), and Other Latin Americans (n = 105). Analysis showed no significant over-all differences among subgroups. No significant subgroup differences in work attitudes were found for women and only one for men. Analysis of subgroup attitudes across age, education, occupation, family income, and personal income also gave no significant differences. These results provide tentative evidence that Hispanic respondents from different countries of origin may be aggregated into a single sample for analysis. There may be no more reason to analyze their responses separately by country of origin than there is to do so for persons of European or African origin.     

Artificial grammar learning in Alzheimer’s disease

Patients with early Alzheimer’s disease (AD) exhibit impaired declarative memory although some forms of nondeclarative memory are intact. Performance on perceptual nondeclarative memory tasks is often preserved in AD, whereas conceptual nondeclarative memory is often impaired. A conceptual nondeclarative learning task that has been studied in amnesic patients is the artificial grammar learning (AGL) task. Healthy participants and patients with impaired declarative memory both acquire information about an underlying rule structure in this task and exhibit the ability to identify rule-conforming items, despite the subjective experience of guessing at the response. In this study, 12 patients diagnosed with early AD were tested on the AGL task and a matched recognition task. The patients were able to reliably distinguish rule-conforming items from others, indicating successful AGL. Performance of the AD patients was impaired, relative to controls, on a similar recognition task, although they were found to use information about the grammaticality of study items in an attempt to improve their recognition performance. The AD patients showed a dissociation similar to that seen in anterograde amnesia: impaired recognition memory in conjunction with successful AGL. This finding suggests that the brain areas that support AGL are not compromised early in the course of AD. In addition, the nondeclarative memory of the AD patients acquired during AGL appeared to influence their performance on a declarative memory task, suggesting an interaction between this nondeclarative memory task and declarative memory.     

Adults returning to school: the impact on family and work

The authors examined the impact of attending a Weekend College (WEC) program on adult students' family, work, and social life. Student participants responded to a 26-item questionnaire and three open-ended questions. Regression analyses of the 566 completed surveys revealed that satisfaction with school and support from family and the work place were predictive of lower levels of stress. Content analyses of responses to open-ended questions showed that expected stress was the result of time constraints but also highlighted the positive aspects of continuing one's education. The study includes suggestions for designing programs to meet the needs of adult students.     

Lack of association of apolipoprotein E polymorphism in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) could be considered a neurodevelopmental disorder, from several lines of evidence. One of the most widely studied genes in these disorders is the apolipoprotein E gene, particularly allele 4. We analyzed for association among patients with OCD versus normal controls and cognitively impaired patients. There were no significant differences between OCD probands compared with population controls. However, the cognitively impaired group showed a higher frequency of allele apolipoprotein E gene compared with normal controls and patients with OCD.     

On Negation for Non-classical Set Theories

We present a case study for the debate between the American and the Australian plans, analyzing a crucial aspect of negation: expressivity within a theory. We discuss the case of non-classical set theories, presenting three different negations and testing their expressivity within algebra-valued structures for ZF-like set theories. We end by proposing a minimal definitional account of negation, inspired by the algebraic framework discussed.