A study on behavioural effects of laboratory rats (albino wistar) after the sub-chronic noise stress

Bodhika J. A. P., Jayakody J. R. I. A.


Background: Humans and animals can hear a wide range of sound frequencies. If the sense of hearing is impaired, both man and animal cannot fare well in their respective environments. Present study is aimed to investigate the behavioral effects following the sub-chronic noise stress of a rat species, Albino Wistar.

Methods: The sound source consists of a set of speakers, GWINSTEK AFG-2000 series function generator and an amplifier. Sound levels and frequencies were monitored by B and K type 2250 sound level meter. Six adult Albino Wistars were exposed to sound frequencies of 1-20 kHz, at intervals of 1 kHz at LAeq of 70-80 dB for 5minute periods and their behavior was recorded. In the second test four adult rats were randomly divided into control and test groups. The test animals were exposed to noise of 7, 8, 9 and 10 kHz for 4hrs daily while keeping the control group in same room for same period of time without exposing to the sound. Locomotive activity, increase of defection and decrease of social activities, of rats was assessed by open field test (OFT). Anxiety and depressive behavior were monitored by elevated plus maze test (EPM) and tail suspension test (TST).

Results: A different behavior in rats was observed in frequency range of 7-10 kHz. At the beginning of exposure, all rats were huddled in a group and then some were frozen into motionless stance. A less time spent and less number of entries in open arm was noticed in test sample compared to the controls in the EPM test. A tendency to move to open field compared to controls was identified in OFT. The TST revealed that a significant increase in immobility time, which indicates a depression like behavior of noise stressed rats compared to controls.

Conclusions: According to the study the most effective noise frequency range for rats is 7-10 kHzl.


Albino wistar, Behavioral effects, Noise stress

Full Text:



Masterton B, Heffner H, Ravizza R. The evolution of human hearing. J Acoustical Society Ame. 1969;45(4):966-85.

Berglund B, Lindvall T, Schwela DH. Guidelines for community noise, World Health Organization, Geneva, Switzerland, London: United Kingdom);1999.

Ravindran R, Devi RS, Samson J, Senthilvelan M. Noise-stress-induced brain neurotransmitter changes and the effect of Ocimum sanctum (Linn) treatment in albino rats. J Pharmacolog Sci. 2005;98(4):354-60.

Sarkaki A, Karami K. Impaired learning due to noise stress during pregnancy in rats offspring. J Res Med Sci. 2004;6:275-9.

Philips CJC. Housing, handling and the environment for cattle. Principles of cattle production. 2009:95-128.

Algers B, Ekesbo I, Strömberg S. The impact of continuous noise on animal health. Acta veterinaria Scandinavica. Supplementum. 1978(68):1-26.

Rabin LA, McCowan B, Hooper SL, Owings DH. Anthropogenic noise and its effect on animal communication: an interface between comparative psychology and conservation biology. Inter J Comparative Psychology. 2003;16(2).

Sun W, Zhang L, Lu J, Yang G, Laundrie E, Salvi R. Noise exposure–induced enhancement of auditory cortex response and changes in gene expression. Neuroscience. 2008;156(2):374-80.

Steru L, Chermat R, Thierry B, Simon P. The tail suspension test: a new method for screening antidepressants in mice. Psychopharmacology. 1985;85(3):367-70.

Cohen S. After effects of stress on human performance and social behavior: Areview of research and theory. Psychol Bull. 1980;88:82-108.

Brouček J. Effect of noise on performance, stress, and behaviour of animals. Slovak J Animal Sci. 2014;47(2):111-23.

Fizza, N, Saida, H. Zehra, B. Tahira, P, Darakhshan, JH. Sub-chronic exposure to noise affects locomotor acivity and produces anxiogenic and depressive like behavior in rats. Razi J Med Sci. 2015;22(135).