The Naturalistic Habitat
The naturalistic habitat (NH) is a novel living environment for rodents that was designed in our lab to imitate the rats’ natural environment. It was designed to promote the expression of natural, innate behaviors such as tunneling and foraging in addition to social interactions among the rats – activities that also promote natural whisker use. The NH was built to study cortical plasticity in adult rats that were transferred to the NH from their standard cage – a small, standard plastic cage, where it is difficult if not impossible to express innate behaviors like the ones expressed in the NH. To study such plasticity we imaged the same whisker representations in the same adult rat before and after they were transferred to the NH - a transfer that induced large-scale plasticity of the whisker representations within the somatosensory cortex (see Polley et al., Nature 2004, Gomez-Pinilla et al. 2011).
The NH is built from a large steel tank (2 m diameter, 1 m high) that was filled with packed sterilized topsoil.
Rats were observed to dig complex, interlocking subterranean tunnel systems that spanned the diameter of the entire tank and they were observed to continuously remodel this system. The above ground artificial tunnel system, built around a central ‘hub’, was designed to make access to food and water more whisker-dependent. Food and water are present at the end of few tunnels but their locations are changed daily. A variety of tactile stimuli (e.g. adhesive tapes with varied textures, holes in the tunnels in varied spatial patterns, protuberant metal bolts) are positioned at locations likely to be contacted by the whiskers as the rats navigate their way through the tunnels. Additionally, the entire above ground tunnel system is disassembled, cleaned, and reassembled in a new configuration once per week.
Examples of our research: (click for deatils)
1) Click here for our emerging view on the large scale functional and anatomical organization of somatosensory cortex,
2) Click here for a new type of plasticity: how stimulation of a single whisker can completely protect the cortex from an impending ischemic stroke,
3) Click here for plasticity induced by transferring animals from their cages to our naturalistic habitat.
4) Click here for a clip showing the 3 phases (intial dip, overshoot and undershoot) of the whisker functional representation evoked within barrel cortex following 1 second of single whisker activation. Based on Chen-Bee et al. (2007).