Excision of whole intact mouse brain

Abstract

Mechanical characterization experiments of brain tissue are performed to understand the mechanical behavior of brain tissue during normal physiology and pathophysiological processes including traumatic brain injury. Normal, healthy, undamaged, unfixed brain tissue specimens are required for these mechanical characterization experiments to ensure the properties being measured are not from damaged/diseased tissue which may lead to inaccurate and unreliable results regarding the mechanical behavior of healthy undamaged brain tissue. The process of excising brain tissue from the cranial vault of mouse cadavers can induce lacerations in the tissue that may affect its mechanical behavior. Therefore, it is imperative that brain tissue samples are excised without inducing damage to the tissue so that the normal undamaged mechanical properties can be measured. Here, a method to excise the entire intact mouse brain is presented:•The scalp is resected exposing the anterior portion of the skull.•Cranial bone is resected by incising along the cranial sutures and using the scalpel blade to remove the cranial segments.•Connective tissue is resected and the brain is removed from the cranial vault.

Keywords: Biomechanics; Brain mechanics; Cranial bone; Dissection; Excision of intact mouse brain; Material characterization; Material properties; Mechanical characterization; Murine; Neural tissue; Traumatic brain injury.

Graphical abstract

Fig. 1

Outline of steps in the excision of intact mouse brain. (a) Make a sagittal incision along the centre of the scalp (white dashed line) using a handled surgical scalpel blade with a pointed tip. (b) Using the scalpel, incise along the sagittal suture of the cranial bone from the intersection of the sagittal and lambdoid sutures to the extremity of the nasal bone. Next, incise laterally across the lambdoid suture. (c) Use the scalpel blade and tweezers to peel back and resect the three segments of cranial bone in the direction of the white arrows exposing the underlying brain. (d) Use the scalpel blade to gently resect any connective tissue anchoring the brain to the lower skull cavity. (e) Use tweezers with rubber tips to gently remove the intact brain from the cranial vault.

Fig. 2

Major (a) cranial and (b) cerebral anatomical structures and landmarks for excision of mouse brain.

Fig. 3

Common damage to mouse brain tissue during excision highlighting a laceration induced during the removal of the cranial bone segments and separation of the olfactory bulbs from the cerebrum.