Effect of Vitamin C Supplementation on Learning and Memory in CD1 Mice.

Vitamin C (ascorbic acid), an ‘over the counter’ supplement, has numerous physiological functions and it is found in high concentrations in the brain. The effect of vitamin C on cognitive memory and visuospatial memory was studied using the Novel Object recognition task (NORT) and the Morris water maze (MWM) respectively. Twenty Swiss white albino (CD1) mice, within the age of 90-120 days, were randomly divided into two groups of ten mice each. Mice in group 1 served as the control and so received normal saline orally while the other group received vitamin C (200 mg/kg) orally for 21 days. All animals had access to feed and water ad libitum. Behavioural testing started on day 21. There was no significant difference in swim latencies between the control and test groups in the MWM though there was a uniform reduction in swim latency in both groups during acquisition and reversal training days. There also was no significant difference in quadrant duration and swim latencies of both groups in the probe trial and the visible platform task. The habituation index is significantly higher in the test group compared to control in the short term inter trial interval of the Novel Object recognition task (NORT). However there was no significant difference in the index of habituation in both groups in the long term inter trial interval of the NORT. There also was a significantly higher index of discrimination in the vitamin C treated group compared to control in the short term inter trial interval of the NORT. There was no significant difference in the index of discrimination in the long term inter trial interval of the NORT. Vitamin C did not affect learning as both groups learned equally well during training in the MWM. It also did not affect visuospatial memory. However, Vitamin C improved short term cognitive memory in the NORT.

The Effect of Long Term Consumption of Powdered Tobacco Diet on Learning and Memory in Swiss White Mice.

Aim: The effects of long term consumption of powdered tobacco (snuff) diet on learning and memory was studied in 30 Swiss white mice. Design: The mice were randomly assigned into two groups (n = 15 each). Mice in group 1 (test group) were fed 1% tobacco diet while mice in the other group (control) were fed normal rodent chow only. Both groups were fed for 31 days before carrying out behavioural testing. All mice were given free access to clean drinking water. Methodology: Food and water consumption by the animals were measured daily while their body weight was measured every two days. The Morris water maze was used to assess Learning and Memory in the mice. Results: The mean daily water and food intake was significantly higher (p<0.01; 0.001 respectively) in the tobacco diet-fed group than in control. The tobacco diet fed group also had a significantly higher (p<0.05) body weight gain than control. The swim latency during the reversal training was shorter in the tobacco diet-fed mice compared to their controls (p<0.01), showing better learning among the tobacco diet-fed group of mice. Southeast (reversal/retention) quadrant duration was also higher in the tobacco diet-fed mice (p<0.01) showing better memory than control. Conclusion: Long term consumption of 1% tobacco diet increased food and water intake, weight gain and improved learning and Memory in mice.

Comparative Effects of Garcinia kola and Coffee Diets on Learning and Memory in Mice.

Background: Garcinia kola (bitter kola) is one of the most common masticatories in Nigeria having social and ethnomedicinal applications. G. kola seeds are believed to contain caffeine, one of the major constituent of coffee which is also believed to improve memory. Aim: This study was set to ascertain the caffeine content of G. kola and compare the effects of G. kola and coffee diets on learning and memory in mice. Methodology: Thirty male CD1 mice were randomly assigned into three groups, viz; control, Garcinia kola diet (30%w/w) and coffee diet (2%w/w) groups. Chemical content and LD50 of the Garcinia kola and coffee were determined using standard methods. Daily food intake, water intake and body weight changes were also measured for 31 days before testing for learning and memory. The Morris water maze was used to assess learning and memory. Results: The major constituents of Garcinia kolawere alkaloids (high quantities), saponins, tannins, flavonoids, glycosides, sterols and phenols found in moderate quantities. The coffee contained high quantity caffeine (4.7%) whereas alkaloids, saponins, tannins, flavonoids, and phenols were present in slight quantities. Coffee diet decreased food intake, water intake body weight change in the mice when compared to G. kola and control diet groups (p<0.05). On the other hand, coffee diet fed mice showed better learning and memory when compared to G. kola diet-fed and control mice. Garcinia kola diet did not affect learning and memory. Conclusion: Coffee diet decreased food and water intake and body weight, but improved learning and memory in mice when compared to Garcinia kola.