Fostering spontaneously hypertensive rat (SHR) pups to Wistar-Kyoto (WKY) dams permanently lowers their adult blood pressure. SHR dams show increased nursing behaviour and the SHR pup displays an exaggerated pressor response to milk ingestion. We have therefore measured pup feeding rates and dam milk secretion rates in SHR and WKY dams nursing natural and foster litters. Maternal behaviour displayed by SHR and WKY dams nursing natural or foster litters and the milk delivery rate to non-fasted pups were measured over postnatal days 1-21. Total milk yield by SHR and WKY dams at postnatal day 6 was measured by comparing the relative weights of milk filled and empty mammary tissue. Fostering SHR pups to WKY dams significantly lowered their mean arterial blood pressure compared with naturally reared SHR pups. SHR dams nursing their natural litters spent more time nursing and less time away from their litters than WKY dams. This difference in behaviour was reduced when dams nursed pups of the opposite strain. SHR dams delivered less milk compared with WKY dams, regardless of pup strain. Total milk yield by SHR dams was significantly lower than that of WKY dams at postnatal day 6, despite comparable mammary tissue mass, suggesting that milk intake by the SHR pup is limited by milk availability, rather than an attenuated maternal response to pup suckling stimuli. The antihypertensive effect of fostering SHR pups to WKY dams may therefore reflect an increase in milk intake during a critical period of growth and development.
1. The aim of the present study was to compare electrolyte handling in naturally reared neonatal spontaneously hypertensive rats (SHR) with those reared by a Wistar-Kyoto (WKY) rat foster mother (denoted SHRX), as cross-fostering SHR pups to a WKY rat dam lowers adult blood pressure in the SHR. 2. The electrolyte content of WKY rat and SHR dams' milk was determined and electrolyte intake and urinary excretion rates were calculated in both naturally reared and cross-fostered WKY rat and SHR pups. 3. The milk sodium concentration fell in both strains (WKY rat: 31.8 +/- 2.0 to 15.2 +/- 1.2 mmol/L; SHR 31.9 +/- 2.5 to 18.2 +/- 1.6 mmol/L; P < 0.001), as did potassium (P < 0.001), over lactation, but there were no differences between strains. Calcium and magnesium concentrations increased (P < 0.001), although SHR dam's milk contained less calcium (P < 0.001) than that of WKY rat dams during the third week of lactation. 4. Spontaneously hypertensive rat pups ingested less milk (P < 0.05) than WKY rat pups; therefore, their cumulative sodium intake over postnatal days 4-15 was significantly lower than that of WKY rat pups (WKY rat vs SHR: 84.4 +/- 3.6 vs 59.7 +/- 2.6 mumol/g bodyweight, respectively; P < 0.05) and fostered SHRX pups (77.7 +/- 7.0 mumol/g bodyweight; P < 0.05). Potassium and magnesium intakes were comparable between SHR, WKY rat and SHRX pups, but SHR pups ingested significantly less calcium than either WKY rat pups (136.1 +/- 6.4 vs 200.1 +/- 9.5 mumol/g bodyweight, respectively; P < 0.05) or SHRX pups (200.0 +/- 18.0 mumol/g bodyweight; P < 0.05). 5. These data show that the neonatal SHR experiences a period of sodium deficiency during the developmental stage when cross-fostering is effective in lowering blood pressure. This is consistent with the reported up-regulation of the renin-angiotensin system observed in SHR at this time and may have a long-term influence on blood pressure.
The spotter test is an assessment that has been used widely to test practical knowledge of anatomy. Traditional spotter formats often focus solely on knowledge recall, in addition to being an onerous marking burden on staff where consistency in marking free text responses can be questioned. First-year optometry students at the University of Manchester study the functional anatomy of the eye in the first semester of their first year. Included in the assessment of this unit is a spotter examination worth 45% of the total unit mark. Due to the factors listed above, a new spotter format was designed. Students had to answer three questions per specimen where the answers to the questions were the labeled structures themselves (A, B, C, or D). They had to work out the answer to the question and then work out which of the labeled structures was the correct structure, negating the "cueing effect" of standard multiple choice questions. Examination results were analyzed over a six-year period (control groups 2008/2009, 2009/2010, 2010/2011; treatment groups 2011/2012, 2012/2013, 2013/2014). There were no significant differences between marks obtained for the new spotter format when compared with the traditional format. The new format spotter tested comprehension rather than just knowledge, and facilitated marking because subjectiveness was erased, and less time was spent determining whether an answer was correct or not. Anat Sci Educ 9: 440-445. © 2015 American Association of Anatomists.
Students enrolled in the Optometry program at the University of Manchester are required to take a functional anatomy course during the first year of their studies. Low mean scores in the written examination of this unit for the past two academic years energized staff to rethink the teaching format. Interactive sessions lasting 20 minutes each were introduced during the two hour lecture sessions. In these sessions students reinforced their anatomical knowledge learned in lectures, through playing games such as anatomy bingo and solving anatomical anagrams. In addition, five e-learning modules were also introduced for students to complete in their own time. A pre- and postcourse questionnaire were distributed to obtain student views on their expectations of the course and interactive sessions. Comparisons were made between written examination results from 2008 to 2009 to written examination results from the previous five academic years to see if the interactive sessions and e-learning modules had any impact on student knowledge. In addition, comparisons were made between student performances on the functional anatomy course with their performance in all of the other assessments taken by the students during their first year of study. Analysis of the questionnaires showed that student's expectations of the course were fulfilled and the interactive sessions were well received by the majority. There was a significant increase (P < or = 0.01) in the mean examination score in 2008-2009 after introduction of the interactive sessions and e-learning modules compared with scores in previous years. The introduction of interactive sessions has increased student enjoyment of the module and along with the e-learning modules have had a positive impact on student examination results.
Cultural influences on anatomy teaching and learning have been investigated by application of a questionnaire to medical students in British and Chinese Medical Schools. Results from the responses from students of the two countries were analyzed. Both groups found it easier to understand anatomy in a clinical context, and in both countries, student learning was driven by assessment. Curriculum design differences may have contributed to the British view wherein students were less likely to feel time pressure and enjoyed studying anatomy more than their Chinese counterparts. Different teaching approaches resulted in British students being more likely to recite definitions to learn, and the Chinese students found learning from cross-sectional images easy. Cultural differences may account for the observation that British students were more inclined to ask questions in class, and the preference of Chinese students to study in small groups. The findings give evidence to show how 'cultures of learning' influence students' approaches and indicate the importance of cultural influences as factors amongst international and home learner groups.
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