MyMedR

Fulltext Role-playing lecturing: a method for teaching neuroscience to medical students

Kumar RS, Narayanan SN

Adv Physiol Educ, 2008 Dec;32(4):329-31.

PMID: 19047513 DOI: 10.1152/advan.90105.2008

An improved light dark box test by using a real-time video tracking system

Narayanan SN, Kumar RS

Acta. Biol. Hung., 2018 Dec;69(4):371-384.

PMID: 30587025 DOI: 10.1556/018.69.2018.4.1

In the behavioral science field, many of the oldest tests have still most frequently been used almost in the same way for decades. The subjective influence of human observer and the large inter-observer and interlab differences are substantial among these tests. This necessitates the possibility of using technological innovations for behavioral science to obtain new parameters, results and insights as well. The light-dark box (LDB) test is a characteristic tool used to assess anxiety in rodents. A complete behavioral analysis (including both anxiety and locomotion parameters) is not possible by performing traditional LDB test protocol, as it lacks the usage of a real-time video recording of the test. In the current report, we describe an improved approach to conduct LDB test using a real-time video tracking system.

Student-involved demonstration approach to teach the physiology of vestibular apparatus for undergraduate medical students

Narayanan SN, Kumar RS, Nayak S

Teach Learn Med, 2011 Jul-Sep;23(3):269-77.

PMID: 21745063 DOI: 10.1080/10401334.2011.586930

It is quite difficult to teach complex topics like the physiology of vestibular apparatus to undergraduate students. Understanding the orientation and mode of stimulation of receptors in vestibular apparatus is also quite challenging for the students. As faculty we attempt to use innovative methods to teach physiology and enhance student learning.

Fulltext Ascorbic acid protects against restraint stress-induced memory deficits in Wistar rats

Kumar RS, Narayanan SN, Nayak S

Clinics (Sao Paulo), 2009;64(12):1211-7.

PMID: 20037710 DOI: 10.1590/S1807-59322009001200012

Chronic stress has been shown to cause oxidative damage in the central nervous system. Although stress-induced impairments in learning and memory have been studied extensively, very few studies have investigated possible ways to prevent their ill effects. The present work was designed to study the protective effects of ascorbic acid in memory loss induced by chronic restraint stress.

Effect of ascorbic acid on the monosodium glutamate-induced neurobehavioral changes in periadolescent rats

Narayanan SN, Kumar RS, Paval J, Nayak S

Bratisl Lek Listy, 2010;111(5):247-52.

PMID: 20568412

In the current study we evaluated adverse effects of monosodium glutamate (MSG) on memory formation and its retrieval as well as the role of ascorbic acid (Vitamin-C) in prevention of MSG-induced alteration of neurobehavioral performance in periadolescent rats.

Analysis of emotionality and locomotion in radio-frequency electromagnetic radiation exposed rats

Narayanan SN, Kumar RS, Paval J, Kedage V, Bhat MS, Nayak S, et al.

Neurol Sci, 2013 Jul;34(7):1117-24.

PMID: 22976773 DOI: 10.1007/s10072-012-1189-4

In the current study the modulatory role of mobile phone radio-frequency electromagnetic radiation (RF-EMR) on emotionality and locomotion was evaluated in adolescent rats. Male albino Wistar rats (6-8 weeks old) were randomly assigned into the following groups having 12 animals in each group. Group I (Control): they remained in the home cage throughout the experimental period. Group II (Sham exposed): they were exposed to mobile phone in switch-off mode for 28 days, and Group III (RF-EMR exposed): they were exposed to RF-EMR (900 MHz) from an active GSM (Global system for mobile communications) mobile phone with a peak power density of 146.60 μW/cm(2) for 28 days. On 29th day, the animals were tested for emotionality and locomotion. Elevated plus maze (EPM) test revealed that, percentage of entries into the open arm, percentage of time spent on the open arm and distance travelled on the open arm were significantly reduced in the RF-EMR exposed rats. Rearing frequency and grooming frequency were also decreased in the RF-EMR exposed rats. Defecation boli count during the EPM test was more with the RF-EMR group. No statistically significant difference was found in total distance travelled, total arm entries, percentage of closed arm entries and parallelism index in the RF-EMR exposed rats compared to controls. Results indicate that mobile phone radiation could affect the emotionality of rats without affecting the general locomotion.

Fulltext Effect of radio-frequency electromagnetic radiations (RF-EMR) on passive avoidance behaviour and hippocampal morphology in Wistar rats

Narayanan SN, Kumar RS, Potu BK, Nayak S, Bhat PG, Mailankot M

Ups. J. Med. Sci., 2010 May;115(2):91-6.

PMID: 20095879 DOI: 10.3109/03009730903552661

The interaction of mobile phone radio-frequency electromagnetic radiation (RF-EMR) with the brain is a serious concern of our society.

Radiofrequency electromagnetic radiation-induced behavioral changes and their possible basis

Narayanan SN, Jetti R, Kesari KK, Kumar RS, Nayak SB, Bhat PG

Environ Sci Pollut Res Int, 2019 Oct;26(30):30693-30710.

PMID: 31463749 DOI: 10.1007/s11356-019-06278-5

The primary objective of mobile phone technology is to achieve communication with any person at any place and time. In the modern era, it is impossible to ignore the usefulness of mobile phone technology in cases of emergency as many lives have been saved. However, the biological effects they may have on humans and other animals have been largely ignored and not been evaluated comprehensively. One of the reasons for this is the speedy uncontrollable growth of this technology which has surpassed our researching ability. Initiated with the first generation, the mobile telephony currently reaches to its fifth generation without being screened extensively for any biological effects that they may have on humans or on other animals. Mounting evidences suggest possible non-thermal biological effects of radiofrequency electromagnetic radiation (RF-EMR) on brain and behavior. Behavioral studies have particularly concentrated on the effects of RF-EMR on learning, memory, anxiety, and locomotion. The literature analysis on behavioral effects of RF-EMR demonstrates complex picture with conflicting observations. Nonetheless, numerous reports suggest a possible behavioral effect of RF-EMR. The scientific findings about this issue are presented in the current review. The possible neural and molecular mechanisms for the behavioral effects have been proposed in the light of available evidences from the literature.

Anti-arthritic potential of the plant Justicia gendarussa Burm F

Paval J, Kaitheri SK, Potu BK, Govindan S, Kumar RS, Narayanan SN, et al.

Clinics (Sao Paulo), 2009;64(4):357-62.

PMID: 19488595

OBJECTIVE: To evaluate the anti-arthritic potential of the plant Justicia gendarussa using two different rat models.

MATERIALS AND METHOD: The anti-arthritic potential of the alcoholic extract of the plant Justicia gendarussa was evaluated using the Freund's adjuvant-induced and collagen-induced arthritic rat models. The rats were treated with the ethanolic extract of Justicia gendarussa and with standard aspirin.

RESULTS: The ethanolic extract of Justicia gendarussa showed significant anti-arthritic activity that was statistically similar to that of aspirin. Our results suggest that the alcoholic extract of Justicia gendarussa exhibits significant anti-arthritic potential.

Spatial memory performance of Wistar rats exposed to mobile phone

Narayanan SN, Kumar RS, Potu BK, Nayak S, Mailankot M

Clinics (Sao Paulo), 2009;64(3):231-4.

PMID: 19330250

INTRODUCTION: With the tremendous increase in number of mobile phone users world wide, the possible risks of this technology have become a serious concern.

OBJECTIVE: We tested the effects of mobile phone exposure on spatial memory performance.

MATERIALS AND METHODS: Male Wistar rats (10-12 weeks old) were exposed to 50 missed calls/day for 4 weeks from a GSM (900/1800 MHz) mobile phone in vibratory mode (no ring tone). After the experimental period, the animals were tested for spatial memory performance using the Morris water maze test.

RESULTS: Both phone exposed and control animals showed a significant decrease in escape time with training. Phone exposed animals had significantly (approximately 3 times) higher mean latency to reach the target quadrant and spent significantly (approximately 2 times) less time in the target quadrant than age- and sex-matched controls.

CONCLUSION: Mobile phone exposure affected the acquisition of learned responses in Wistar rats. This in turn points to the poor spatial navigation and the object place configurations of the phone-exposed animals.

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