An inexpensive mouse headholder suitable for optical recordings

An inexpensive headholder for mice ranging from 3-week-old animals to adults was designed to provide reliable long-term head fixation. Its shape allows the direct access to the dorsal and ventral sides of the head which makes the headholder ideal for the use with both an upright and an inverted microscope. Because the headholder does not use a nose clamp, the apparatus allows surgery, stimulation of the olfactory system and concomitant optical recording of neuronal activity.