Clamp options for the Mobile HomeCage devices

Stability is one of the most important factors – if not the most important factor – in selecting the head fixation for two-photon imaging and electrophysiological recordings in awake mice. This is why the clamp and head plate design are so important. This is also the reason why we continuously innovate the clamp design and expand the variety of clamp options.

Please use the menu below to navigate to the relevant clamp option:

Comparison between two main clamp options

The Mobile HomeCage® devices come with a choice of two clamps that must be specified at order: the standard clamp (top picture, left) and the Levelt clamp (top picture, right). While both clamps provide the same level of stability, they differ in several respects. The table below provides a quick reference guide to choosing between the two options:

*) Beware of possible magnetic field interaction between the clamp and the cage magnets (this is relevant for the Mobile HomeCage with locomotion tracking capabilities only). Tests have shown that this interaction does not affect mouse behavior. Nevertheless, avoid leaving mice with magnetic head plates in the cage with tracking mats without first head-fixing them in the clamp.

Please note that the smallest unit we sell to the labs that don’t have the Mobile HomeCage devices is the clamp kit (standard or Levelt), which includes a clamp, a neck, a rotation block, and 10 head plates. Contact mhc-support@neurotar.com to order.

Standard clamp

The standard clamp is secured with two thumbscrews. It is compatible with a wide range of head plates designed for different research needs. In addition to the straight clamp (0-degree tilt), the clamp can be manufactured with a 10, 20, 30 and 35-degree tilt (inclination in the nodding direction). The clamp rotates up to 40 degrees in both directions (left and right inclination) either as a continuum or in 10-degree steps. Besides that, the clamp has attachment holes for mounting liquid reward, miniature cameras, and other auxiliary devices.

The gif below illustrates imaging stability in the brain of an awake mouse expressing GCaMP6 (please note that the image sequence is not motion-corrected):

Imaging stability GCaMP6 awake mouse

Tilted clamp

The tilted clamp is a variant of the standard clamp. It allows adjusting the mouse’s head position in the nodding direction. Beware that the tilted clamps cannot be used for imaging without a tilting objective mount. Please remember to specify the degree of tilt at the order. The straight clamp (0-degree tilt) is a default option. Other options include 10, 20, 30 and 35-degree tilt. The degree of tilt cannot be adjusted.

Customer labs that wish to replace their straight clamp (0-degree tilt) with a tilted clamp (10, 20, 30 or 35-degree tilt) or add a tilted clamp as a second option, please contact mhc-support@neurotar.com

Levelt clamp

The Levelt clamp was developed by Christiaan Levelt’s lab at the Netherlands Institute for Neuroscience. The clamp is magnetic. It allows head-fixing a mouse quickly and effortlessly. This clamp must be used with a dedicated magnetic head plate (currently only one model # 13 is available). There is currently no tilted version for this clamp. The clamp rotates up to 40 degrees in both directions (left and right inclination) either as a continuum in 10-degree steps. Besides that, the clamp has attachment holes for mounting liquid reward, miniature cameras, and other auxiliary devices.

The Levelt clamp is suitable for imaging/recording in the somatosensory cortex of adult mice (age > 2 months; weight > 20g). The gif below illustrates imaging stability (of the dendritic spines) in awake behaving mice (please note that the image sequence is not motion-corrected):

Imaging stability in Levelt clamp

The below pictures of the standard viz-a-viz the Levelt clamp are taken from roughly the same angles to illustrate the mouse’s field of view in each clamp. The pictures are taken in the extra low-wall cage for demonstration purposes:

Levelt and standard clamp

Levelt vis-a-vis standard clamp top view

Levelt vs standard clamp field of view

Customer labs that wish to replace their standard clamp with the Levelt clamp or add the Levelt clamp as a second option, please contact mhc-support@neurotar.com

New! fUS clamp

Are you aware of the benefits of functional ultrasound (fUS) imaging brought to the market by a French startup Iconeus? Are you already using the Iconeus One system and wish to adapt it for imaging in awake head-fixed mice? We have a special fUS clamp for you!

The central opening is larger than in the standard clamp. This is done to accommodate the fUS head plate (model 14). Both the clamp and the head plate were designed for optimal fit with Iconeus’ fUS imaging probe. If you are planning to use the Mobile HomeCage in combination with Iconeus One system, let us know and we shall replace the standard clamp with the fUS clamp. If you wish to order the fUS clamp in addition to the standard clamp, please contact us at mhc-support@neurotar.com