A cooling/heating system for use with in vitro preparations: study of temperature effects on newborn rat rhythmic activities.

We have developed a universal stage that is particularly suitable for use with vertebrate and invertebrate in vitro preparations. Based on the Peltier effect, the same compact apparatus can be used to cool or heat within a wide temperature range (from 5 to 50 degrees C). Due to the use of interchangeable rings, the stage is compatible with a wide variety of dishes. We used this system to analyze the effects of temperature on the spinal networks that generate fictive locomotion in newborn rats. The results showed that these spinal networks can be active in a wide temperature range, producing an organized pattern (bursts alternating between the right and left sides) even at very low temperatures (15 degrees C). From 15 to 20 degrees C the period decreased before reaching a plateau (between 20 to 30 degrees C).