Pharmacological effects of cannabinoids on the reference and working memory functions in mice

Rationale

Evidence indicates cannabinoid receptor agonists impair performance in procedures to assess memory that may also be confounded by motivational or motor effects, both of which occur with cannabinoids. Thus, convergence of evidence from a variety of procedures that differ in motivation, attention, arousal and response requirements, but share a common reliance on memory, is required. There are no current reports on cannabinoid effects on mice tested in the radial arm maze.

Objectives

The objective was to determine the effects of the cannabinoid agonist CP 55940 and the dependence of any such effects on the CB1 receptor using the CB1 receptor antagonist SR 141716A on two strains of mice in the eight-arm radial maze procedure.

Methods

Male C57BL/6J (N?=?36) and C3H/HEJ (N?=?12) mice were trained to a criterion and then were treated (IP) with vehicle?+?vehicle, SR 141716A?+?vehicle, vehicle?+?CP 55940 and SR 141716A?+?CP 55940 in a fully balanced mixed design prior to further tests in the maze. Reference (long-term) and working (short-term) memory were assessed.

Results

CP 55940 impaired performance of the reference memory task in the C57BL/6J strain but not the C3H/HEJ strain; SR 141716A reversed the effect of CP 55940 on these measures. CP 55940 also increased working memory errors in the C57BL/6J mice only, which was not affected by SR 141716A.

Conclusion

The present study provides evidence for a strain-specific effect of a dose of CP 55940 on reference memory. While the cannabinoid agonist also impaired working memory in one strain, this effect was apparently not mediated by CB1 receptors.     

A case of interesting neck mass

Neck Mass poses problems to clinicians and pathologists. A case is reported where the Primary and Secondary showed different histopathological pictures.     

Memory function in a mouse genetic model of Alzheimer's disease

The E4 allele of the apolipoprotein E (ApoE) gene has been identified as a major risk factor for the development of late onset Alzheimer's disease (AD). However, the mechanisms by which this gene affects AD are not fully understood. Studies of ApoE knock-out (ApoE KO) mice have revealed an exacerbation of two major pathologies that are diagnostic of AD: neurofibrillary tangles and senile plaques. However, evidence as to whether these mice have cognitive deficits is not yet conclusive. This ambiguity may arise partly from confounds associated with reliance on limited memory models, primarily, the Morris water maze task. An 8-arm radial maze task was therefore used to measure spatial memory in the ApoE KO mice, compared to controls over time. Furthermore, the effectiveness of a combination antioxidant therapy (CAT), designed to slow down the progression of AD based on concepts of oxidative stress and inflammatory processes underlying the pathology, was tested on memory ability. A significant strain difference was observed with the ApoE KO mice performing better than controls in terms of reference memory and corrects entries. No significant strain difference was observed for performance in terms of working memory errors. No significant effect of the CAT supplementation was observed.     

Partnerships for interdisciplinary collaborative global well‐being

Health is a state of complete physical, mental, and social well‐being and not merely the absence of disease or infirmity. The multifaceted intertwined nature of optimal health, mental health, and well‐being requires operational, sustainable interdisciplinary partnerships in order to improve personal and global well‐being and happiness. The initial step must be the assessment of the nature and magnitude of local problems in the global context. The WHO annual reports may be an adequate departure point as they can demonstrate the global nature of stressful situations and their association with physical and mental stress‐related disorders. Therein, mental health professionals should spearhead change and progress. Attitudes need to be pro‐active and partnerships are essential. Pertinent data should be evaluated by local experts who will determine the needs and how best to face them and achieve solutions. Hopefully, common regional denominators will lead to the formation of Regional Interdisciplinary Collaborative Alliances (RICAs) who will share needed resources and focus particularly on vulnerable populations. The RICAs would be supported by experts and technological facilities located in developed economy centers. The long‐term goal is to turn the concept of pursuit of happiness into a well‐perceived reality.     

Off-pump coronary artery bypass: the Sudbury experience

OBJECTIVE: To examine factors relating to outcomes with off-pump coronary artery bypass (OPCAB) and to assess methods to improve the effectiveness of this approach SETTING: A small northern Ontario community hospital where surgical assistance, nursing familiarity with OPCAB and even anesthesiologist comfort varied DESIGN: Prospective collection of data with incremental audit of results and retrospective analysis of events METHODS: One hundred twenty-four consecutive patients, operated on by the same surgeon between April 1996 and June 2002, were selected on the basis of coronary anatomy. Progressively more complex multivessel revascularization, including that to the posterior wall, was undertaken over the course of the study period. Every attempt was made not to compromise use of arterial conduits, quality of anastomoses or completeness of revascularization. This represents the 'learning curve' of this study. MAIN RESULTS: Approximately 6% of patients developed a hemodynamic crisis requiring acute on-pump conversion. This tended to occur in patients undergoing complex multivessel OPCAB surgery and was associated with subsequent increased blood transfusion rate, operative time and mortality (2.8%), and poorer angiographic graft patency. This has led to a more cautious strategy including making the decision to proceed with OPCAB only after intraoperative assessment. CONCLUSION: 'Simple' OPCAB on easily accessible coronary arteries resulted in excellent early outcomes. Complex multivessel OPCAB for triple vessel disease involving difficult to access arteries was more demanding with higher perioperative complications and less effectiveness. Early enthusiasm for complex multivessel surgery has been gradually replaced with a more conservative use of OPCAB with improved intraoperative procedures, both of which have led to more favourable outcomes.     

Corticosteroid dependent and independent effects of a cannabinoid agonist on core temperature,motor activity,and prepulse inhibition of the acoustic startle reflex in Wistar rats

Rationale  

There are inconsistent reports on the effects of cannabinoid agonists on prepulse inhibition of the startle reflex (PPI) with increases, decreases, and no effects. It has been hypothesized that the conflicting observations may be as a result of modulation of the effects of cannabinoid agonists by the regulation of corticosteroid release.