Analyzing Spatial Learning and Prosocial Behavior in Mice Using the Barnes Maze and Damsel-in-Distress Paradigms

Summary

This protocol measures spatial learning and memory using the Barnes maze. A novel Damsel-in-Distress paradigm is used to assess locomotor activity and prosocial behavior in mice.

Abstract

The Barnes maze is a reliable measure of spatial learning and memory that does not require food restriction or exposure to extremely stressful stimuli. The Barnes maze can also assess other mouse behaviors, such as general motivation to escape from the maze platform and exploratory behavior. The Barnes maze can measure whether a genetic mutation or environmental variable can impact the acquisition and retention of spatial memories, as well as provide information about the search strategy employed by the mice. Here we use the Barnes maze to detect a memory deficit in adult mice following a single developmental ethanol exposure event. The newly described Damsel-in-Distress paradigm exposes a male mouse to a female mouse trapped in a chamber in the open center field of the arena. It provides an opportunity for the mouse to socially respond to the trapped female and exhibit prosocial behavior. The Damsel-in-Distress paradigm can also be used to examine mouse behavior in a novel arena and measure locomotor activity. Both the Barnes Maze and the Damsel-in-Distress protocols require minimal financial investment and most aspects of the tests can be constructed from common lab supplies. These flexible and accessible tools can also be used to detect behavioral changes over the course of development.

Introduction

The purpose of this protocol is to measure spatial learning and memory in mice using the Barnes maze as well as social responsiveness and locomotion using the Damsel-in-Distress paradigm. Commonly used spatial learning and memory tests for rodents include the radial arm maze, which measures a mouse's ability to find hidden food in one arm of a multi-spoked apparatus, and the Morris water maze, which places a mouse in a large tub or pool of water and assesses how long it takes to find a hidden underwater platform. Typically, training for these paradigms spans multiple trials and allows the measuring of both learning acquisition rates and retention through short ter....

Protocol

All methods described here were approved by the Institutional Animal Care and Use Committee (IACUC) of Hampden-Sydney College or Randolph-Macon College (where some work was previously performed).

1. Basic Housing of Mice

1. House the mice in plastic cages with solid bottoms and sides, and a layer of soft bedding and nesting material such as paper shredding. Use bedding that is composed of shredded corn cobs or wood shavings, and ensure that the bedding is changed regularly for sanitation.
2. Provide access to food and water ad libitum. The top of the plastic cage houses a food hopper. Dispense properly formulated mo....

Results

The Barnes Maze

To illustrate how the Barnes maze can be used, we investigated whether a single early ethanol exposure caused a difference in learning over the course of mouse development. C57Bl6/J mice were either injected with a 2.5 g/kg ethanol solution (n = 8) or with saline (n = 6) twice, two hours apart, at postnatal day 6. We trained the animals on the Barnes maze during adolescence (P30), then p.......

Discussion

The Barnes maze and the Damsel-in-distress experiments are inexpensive, quick, and relatively easy ways to evaluate spatial learning, locomotor activity, and prosocial behavior in mice. Other advantages include the absence of overt stressors, pain, or food restriction for the animal. Like most learning/memory paradigms, a disadvantage of the Barnes maze is the number of trials required for the animals to learn where the target hole is located and enter.

Data collection:

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Damsel-in-Distress
50 mL conical tube	Fisher Scientific	14-432-22	Any brand of 50 mL conical tube will work
Rubber bands	Sprano Brand	n/a	Size 62, used to keep caps held to plywood
hammer	Grainger	6R252	Any standard hammer will work
nail (size 8D)	Grainger	4NFE3	Similarly-sized nails should work just as well
opaque, topless plastic box	AcmePlastics	CUT-TO-SIZE-ACRYLIC-CAST-BLACK-SHEET-2025	Opaque plastic, cut to size (30 cm L x 19 cm W x 3-6 cm H). Step may be added to ensure no more than a 3.5 cm entrance depth for the mouse.
video camera (smartphone)	N/A	N/A	Any camera-equipped smartphone will work
bite-resistant gloves	Kent Scientific	GLVDYN02	Any brand offering appropriate protection
transparency sheet	Staples	954145	Any brand of clear plastic sheet will work, used for scoring
Barnes Maze
Petri Dishes	Corning	353025	Spray painted and used as covers for Barnes maze holes
Plywood (3/4 in.)	LP Building Products	22487	To construct Barnes maze
Spray Paint	Krylon	1274937	Used to paint petri dish caps black, white paint used to paint plywood
Cup Hooks (5/8 in.)	Ace Hardware	5360615	2 used on either side of ventral hole surfaces; Rubber band wraps around hooks to hold cap flat
Poster Board	Creatology	n/a	Used at edges of maze as extra cues
Light Bulbs	Phillips	n/a	100W light bulb, used to during the trials
Rubber bands	Sprano Brand	n/a	Size 62, used to keep caps held to plywood
Ultrasonic noisemaker	Victor mini PestChaser	M753SN	Used as aversive stimuli