The authors have no acknowledgements.

Ethics statement: All procedures were approved by the Animal Ethics Committee of the University of Sydney and conformed to National Health and Medical Research Council of Australia guidelines. Procedures were performed on C57/BL6J mice which were reared at the University of Sydney Bosch Rodent Facility. All mice were housed in a single adequately-ventilated room in 21 &#176;C ambient temperature on a 12 hr light-dark cycle with lights on at 0600 hr in individually ventilated cages with ad libitum access to dry f...

The authors declare they have no competing financial interests.

The data presented demonstrate that the Puzzle Box can be used effectively to assess the impact of EE. Mice raised in enriched environments consistently took significantly less time to solve obstruction puzzles within this behavioral assay than did animals raised within standard laboratory conditions. Moreover, this difference was most prominent in the first trial for three of the four conditions tested, suggesting EE has a greater influence on an animal&#8217;s native problem-solving ability, relative to their capacity ...

Environmental enrichment (EE) may be defined as surroundings that provide animals with increased opportunity for social interaction, motor activity, and greater sensory stimulation than usually experienced in a standard laboratory environment.EE has been shown to consistently affect the behavior of animals, bringing about changes such as reduction of stress and anxiety-related activity 8-10, improved performance in learning and memory tasks 8,11, early onset of motor coordination and exploratory activity 11, changes in maternal care 8 as well as resistance to addictive substances 12-15. Further, EE has been revealed to ameliorate the effects of neurodegenerative disorders, delaying the onset and decreasing the severity of symptoms in animal models of Huntington&#8217;s 1-4,16, Parkinson&#8217;s 17 and Alzheimer&#8217;s disease 18.
These changes correlate with the anatomical and molecular alterations EE is known to induce throughout the brain. Animals raised in enriched environments from early stages of development show a myriad of neural changes, including increased brain weight and cortical thickness, dendritic branching 9,2-22 and synaptic density 23. EE can alter both the level and timing of growth factor expression 9,24-30, which has been shown to contribute to accelerated development of sensory 25,26,28,29, mnemonic 30, as well as motor circuits 31,32.
Previous work has revealed at times contradictory findings when investigating the impact of EE, without taking into account the different types of animals and environments used within individual studies 9,24,27,30. Currently, there is no consistent and simple behavioral task that can be used to measure the effectiveness of various EE paradigms in different strains and species of animals.
The Puzzle Box task was designed as a simple test to determine an animal&#8217;s native problem solving ability 7. Animals placed in the open area are required to remove obstructing materials situated within a small opening in order to access a covered region/shelter. Each subject is given three trials with the same obstruction in order to assess three different cognitive attributes. The first trial yields a baseline indication of inherent or native problem solving ability. The second trial, run on the same day, gives some indication of the animal&#8217;s ability to improve upon and thus reinforce strategies for removing the specific obstruction. The third trial, conducted on the following day, provides insight into the ability of the subject to retain and recall the learned solution to the task.
The motivation for solving these &#8220;obstruction puzzles&#8221; by the animals can be varied, potentially evoking an innate desire to avoid open fields and seek shelter, as well as an inherent drive to explore their surroundings 6,7. The multitude of potential behavioral drivers underlying the desire to solve the Puzzle Box suggests that various areas of the brain are involved in mediating task performance. Previous work has shown that in murine models of schizophrenia, the prefrontal cortex as well as the hippocampus are involved in the acquisition of this task 5. A lesion study in rats has also revealed a large number of brain regions involved in Puzzle Box performance, including various thalamic nuclei, the hypothalamus, the cerebellum, and limbic structures. Together, these findings indicate that engaging in this problem solving task involves a host of neural structures associated with cognitive function.
The Puzzle Box has been used successfully to assess the problem solving ability of mice, as well as cognitive deficits exhibited by murine models of schizophrenia 5-7. Performance on the task has been shown to be highly consistent, and correlate well with outcomes of other cognitive behavioral tests 6. The goal of this work was thus to adapt the Puzzle Box task to become a simple and reliable means of determining the effectiveness of EE.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Black Acrylic Board</td>
			<td></td>
			<td></td>
			<td>750 x 280 mm</td>
		</tr>
		<tr>
			<td>White Acrylic Board</td>
			<td></td>
			<td></td>
			<td>280 x 250 mm</td>
		</tr>
		<tr>
			<td>White Acrylic Board</td>
			<td></td>
			<td></td>
			<td>280 x 250 mm</td>
		</tr>
		<tr>
			<td>White Acrylic Board</td>
			<td></td>
			<td></td>
			<td>750 x 250 mm</td>
		</tr>
		<tr>
			<td>White Acrylic Board</td>
			<td></td>
			<td></td>
			<td>750 x 250 mm</td>
		</tr>
		<tr>
			<td>White Acrylic Board</td>
			<td></td>
			<td></td>
			<td>150 x 280 mm</td>
		</tr>
		<tr>
			<td>White Acrylic Board</td>
			<td></td>
			<td></td>
			<td>280 x 250 mm with a 40 x 40 mm &#34;door&#34; cut into one side</td>
		</tr>
		<tr>
			<td>Underpass</td>
			<td></td>
			<td></td>
			<td>3 pieces of 40 x 120 mm plexiglass or acrylic</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Note: If unable to access acrylic board, plexiglass or similar non-porous material will suffice.</td>
		</tr>
		<tr>
			<td>Webcam</td>
			<td>Logitech</td>
			<td>C210</td>
			<td>Fix to roof with electrical tape. Alternatively, use a tripod.</td>
		</tr>
		<tr>
			<td>VirtualDub v1.10.4</td>
			<td>VirtualDub</td>
			<td>N/A&#160;</td>
			<td>Software for recording behaviour videos. Input from webcam.</td>
		</tr>
		<tr>
			<td>TopScan v 3.0</td>
			<td>CleverSys Inc.</td>
			<td>N/A&#160;</td>
			<td>Software for automated top-view tracking and analysis of mouse behaviour. Captured videos are analysed post-hoc.</td>
		</tr>
	</tbody>
</table>

the use of the puzzle box as a means of assessing the efficacy of environmental enrichment

Environmental enrichment can dramatically influence the development and function of neural circuits. Further, enrichment has been shown to successfully delay the onset of symptoms in models of Huntington&#8217;s disease 1-4, suggesting environmental factors can evoke a neuroprotective effect against the progressive, cellular level damage observed in neurodegenerative disorders. The ways in which an animal can be environmentally enriched, however, can vary considerably. Further, there is no straightforward manner in which the effects of environmental enrichment can be assessed: most methods require either fairly complicated behavioral paradigms and/or postmortem anatomical/physiological analyses. This protocol describes the use of a simple and inexpensive behavioral assay, the Puzzle Box 5-7 as a robust means of determining the efficacy of increased social, sensory and motor stimulation on mice compared to cohorts raised in standard laboratory conditions. This simple problem solving task takes advantage of a rodent&#8217;s innate desire to avoid open enclosures by seeking shelter. Cognitive ability is assessed by adding increasingly complex impediments to the shelter&#8217;s entrance. The time a given subject takes to successfully remove the obstructions and enter the shelter serves as the primary metric for task performance. This method could provide a reliable means of rapidly assessing the efficacy of different enrichment protocols on cognitive function, thus paving the way for systematically determining the role specific environmental factors play in delaying the onset of neurodevelopmental and neurodegenerative disease.

The results described here are a representative sample, with data taken from several cohorts consisting of different litters. All behavioral testing was conducted between 0700 and 1100 hr, with randomized testing order of animals within a cohort. Animals raised in an enriched environment (n = 14, 7 female and 7 male) took significantly less time to solve the obstruction tasks within the Puzzle Box than those raised within a standard environment (n = 15, 7 female and 8 male) (see Figure 3) (Repeated measu...

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The Use of the Puzzle Box as a Means of Assessing the Efficacy of Environmental Enrichment

Environmental enrichment provides a potential protective effect against neurodegenerative disorders. Currently, however, there is no easy way of determining the efficacy of enrichment procedures. This protocol describes a simple &#8220;Puzzle Box&#8221; method for assessing an animal&#8217;s cognitive function, in order to reveal the effectiveness of environmental enrichment.

Environmental enrichment can dramatically influence the development and function of neural circuits.  Further, enrichment has been shown to successfully ...

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11.5K ビュー.  University of Sydney. Environmental enrichment provides a potential protective effect against neurodegenerative disorders. Currently, however, there is no easy way of determining the efficacy of enrichment procedures. This protocol describes a simple “Puzzle Box” method for assessing an animal’s cognitive function, in order to reveal the effectiveness of environmental enrichment.