Choice test mazes

A four-choice star maze, similar to that used by Kubie and Halpern (1978, 1979), was used as a two-choice Y maze for training the snakes. Snakes were trained to follow earthworm extract trails (IX = 6 gm earthworm per 20 ml dH20) in the apparatus until their performance exceeded chance behavior. (See Kubie and Halpern 1978 for details). At the termination of testing, snakes were videotaped during trailing at each earthworm concentration (IX, 1/9X, 1/8IX, Dry). Trials were repeated until a minimum of one minute of good, analyzable film had been obtained at each concentration. This usually involved one to three trials. For filming of animals from the side, a clear plastic maze of similar dimensions was used. 

Using a series of Y-maze olfiictoiy choice tests, we found that male red-spotted newts show a pheromonal repelling response and that the occurrence of the repelling response depends on the number of males present, on male-female interactions, and on female fecundity. The purpose of the work presented here is to describe and elaborate on the main findings that we have reported in previous studies (Experiment I-IV, Park and Propper, 2001 Experiment V-VI, Park et al., submitted). 

Table 1. Results of the Y-maze olfactory choice tests.

Figure 7.3. Mazes constructed for two-choice test (A) the choice point located at the end of the initial runway and (B) the choice point located at the start box. For scale, each arm of the maze is 1 m.

Fig. 23.1 Results of the odor preference test in a Y-maze (A). Female mice carrying lesions in either the MOE (B) or VNO (C) were given a choice between volatile odors derived from an intact or a gonadectomized male...

Subsequent to maze habituation, all animals are submitted to 3 test sessions on 3 consecutive days. During a test session each animal is placed individually in the centre of the maze and allowed to make 8 choices after which it is removed from the apparatus. If the animal does not complete 8 choices within 5 minutes, it is removed and its scores discounted for that day. If the animal is in the course of making its 8th choice... 

Two-way choice apparatus (T-maze) for testing mouse responses to odors of conspecifics... 

This exercise and the next both deal with scent communication in mice. We practice two techniques frequently used in the Animal Behavior laboratory In this first experiment, we test a mammal s response to conspecific odors in a two-way choice apparatus, also called a Y- or T-maze, an often used bioassay device. [In the following experiment (Chap. 21), we observe and quantify scent marking behavior in response to two different stimuli in an open field. ]... 

In the T-maze we can test the responses of a male or female to a urine mark of the opposite sex, or from dominant or subordinate individuals of the same sex, or some other difference of interest. Among the many studies using two-way choice apparatuses for mice, a good example is a paper by Krasnov and Khokhlova (1996) that deals with mice responding to odors of another rodent species. We will test responses of males and females to urine of the same and different sex in a two-way choice apparatus (T-Maze). 

To test their ability to discriminate individuals, male and female salamanders (in the US several species of the genus Plethodon) are given a choice of odors in a Y-maze. The odors tested can be male vs. female mate vs. strange individual of opposite sex individuals from different populations or closely related species (Dawley 1985). 

In the T-maze the rat must correctly choose between the left or right arm to obtain food pellets (Fig. 6b). Audio, olfactory, or visual cues may guide the choice, and provide a test for efficacy of working memory. The data collected can be time to goal and percent correct choices. One arm may be covered to assess the effect of learning versus the normal tendency of the rodent to seek the darker passage. 

To determine whether female fecundity affects male choice, we determined whether or not subject males display a preference when presented with large and small females. We placed one large (3.75 0.57 g, n = 5) and one small (2.67 0.18 g, n = 5) female into each arm of Y-maze and allowed subject males to choose between them. Males showed a strong preference for the side containing the large female (Table 1, V one-tailed binomial test, P < 0.001). 

Quinine-Aversion Test. For the quinine-aversion test, we used the same Y-maze. In this case, however, fluid-deprived mice were trained to avoid the androstenone-containing arm of the Y-maze in training and testing that commenced 5 weeks after exposures for all groups of animals. Quinine-tainted water (1%), paired with androstenone, produced the aversion—each time the animal entered the androstenone-containing arm and licked the sipper tube, it received the quinine. Sweetened water was the reward for correct choices (the non-odorized arm of the Y-maze). 

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