The Effects of Different Stimuli on the Exploratory Behavior of Mice

THE EFFECTS OF DIFFERENT STIMULI ON THE EXPLORATORY

BEHAVIOR OF MICE

Alvarez, Ma. Lemie G.

Group 3 Sec. U-1L

October 24, 2018

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        1A scientific paper submitted in partial fulfilment of the requirements in Zoology 122 Laboratary class under Prof. Eleanor Aurellado, 1st sem., 2018-2

ABSTRACT

The exploratory behavior of mice was observed. Two samples of mice for each group were studied. Each mouse was placed in an aquarium covered with black garbage bag and provided with adequate beddings such as old newspapers. A feeding tray with tap water which served as the novel stimulus was introduced and after 15 minutes it was replaced by another tray with vinegar as noxious stimulus. Same procedure was done when the cat urine was placed.. The general behavior of the animal in relation with the different stimulus was recorded. The results show that presence of stimuli does not significantly affect the number of visits of mice and the mice do not equally spent their time for both zones regardless of the presence of the stimulus. Furthermore, the presence of stimuli does not have an effect on whether or not the mice will stay longer in each zone.

INTRODUCTION

Exploring the surroundings in a heterogenous environment is one way for the animals to reduce uncertainty and become more familiar on a particular area where they can live with access to different resources such as food (Tebbich et al. 2009; Vanden et al. 2017) or mates (Schwagmeyer 1995; Vanden et al. 2017). Most mammals like mice when they leave their maternal nest, have tendency to roam around in a wide area but afterwards they tend to confine and limit their movements to a certain sites which is known as home range (Vanden et al. 2017). The physical features within the home range including available resources and dangers will be learned by the mice through a specific type of behaviour called exploration (Vanden et al. 2017) which increases the knowledge of the animal about their environment (Pisula, 2004) including their home range or territory that will be vital for survival.

Exploratory behaviour is defined as a novelty seeking activity which is performed without motivation wherein there is no incentive present (Barnett & Cowan 1975; Frynta, 1993), so it is expected that “unmotivated learning” is acquired while it is being carried out (Barnett, 1956). Exploratory behaviour can be identified as extrinsic or intrinsic. Extrinsic exploration consists of responses towards obtaining information regarding food or nesting sites which act as reinforcers. Conversely, intrinsic exploratory behaviour is defined as stimuli directed exploration that may not be important in biological aspect. One example is the investigation of animals towards a novel object in their usual normal environment (Vanden et al. 2017). Exploratory behavior can be influenced by external factors and stimuli (Barnett, 1956). Novelty, complexity and spaciousness are the exploratory drive which can be associated with the stimuli. Novelty or ‘change’ may perceive as either new in relation to one’s previous experiences (Barnett, 1956) which is known as relative novelty or as absolute novelty which is new in terms of the whole history of an individual especially by adult animals (Cowan, 2016). In addition, animals react to different stimuli in different ways (Cowan, 2016). In relation with that, there are two tendencies such as neophilia and neophobia in which the animals respond to the present stimuli (Shepp, 1966). Neophilia is the tendency to approach and explore the novel stimuli while neophobia causes withdrawal or avoidance of such stimuli. The balance between the two tendencies is the behaviour of animals toward the novel stimuli (Shillito, 1963; Shepp, 1966)

        Small mammals like mice may perform variable responses to different stimuli. This experiment sought to confirm if the mice possess neophilia towards novel stimulus and neophobia towards the non-palatabe materials which are the vinegar and cat urine. Since water, cat urine and vinegar will be perceived by the mice and will respond to them based most likely on the odor.

The exercise was conducted on October 3, 2018 at the NCAS building, University of the Philippines Los Baños. The objective of the exercise is to determine the exploratory behavior of small rodents when they encountered different stimuli. Specifically, it aimed:

1.  to determine the behavioral changes that constitute neophobia and      

    neophilia; and

 2. to understand the role of neophobia in terms of the survival of animals in                  

     their natural environment    

METHODOLOGY

To observe the exploratory behavior of mice, two adult samples were collected. Six samples for each group were observed. An aquarium covered with black garbage bag to avoid reflection and external stimuli. Inside the aquarium have adequate beddings of old newspaper. Each mouse was placed inside the aquarium for at least teTn minutes for initial observation before the actual test, and then the number of visit of animals and the duration of time spent in each visit along the assigned test area were recorded. After that, feeding tray with tap water which will serve as novel stimulus was placed in the designated test area with great care to avoid disturbance in the mouse. It mouse was observed for 15 minutes.

        To observe neophobia in mice, the tap water was replaced by vinegar and cat urine. For each stimulus, there was 15 minutes observation time and  the number of visit of animals, the duration of time spent in each visit along the assigned test area were recorded and the general reaction of the animal to the given stimulus were recorded. Upon getting the results, the mean frequency visit was computed and the patterns of exploratory behavior of mice using ANOVA were determined.

RESULTS

[pic 1]

             Figure 1. Mean frequency of visits on each introduced stimulus

        The number of visits of mice in the three introduced stimuli was compared. Based from the consolidated data from the three groups, the set-up with cat urine has the highest number of visits among three set-ups (Fig.1). It was followed by the vinegar set-up then the water which acted as a novel stimulus. However, it can be seen from the graph (Fig.1) that the computed values for the mean frequency of visits on each introduced stimulus do not have large differences and the presence of stimuli does not significantly affect the number of visits of mice (p=0.778).