Visualization of Trigeminal Ganglion Neuronal Activities in Mice

Abstract

Visualization of dynamic cellular activity has greatly expanded our understanding of brain function. Recently, there has been an increasing number of studies imaging rodent brain activity in real time. However, traditional in vivo calcium imaging technology has been limited to superficial brain structures. Because the trigeminal ganglion (TG) is located deep within the cranial cavity of mice, few studies have been able to access to it. To circumvent this limitation, overlying brain tissue must be removed to expose the TG so that optical recording can access deep brain neural ensembles. This unit describes a procedure for conducting non‐survival surgery to visualize the TG in live mice. Obtaining large ensembles of direct, real‐time readouts of sensory neuron signaling, providing temporal and spatial information across the TG, will help to define the cellular basis of orofacial somatic sensing and pain perception. © 2019 by John Wiley & Sons, Inc.

Visualization of trigeminal ganglion sensory neuronal signaling regulated by Cdk5

“…Surgical procedures were conducted as described previously (Ghitani et al, 2017;Hu, 2019). In brief, mice at 8-10 weeks of age were anesthetized with inhalational Isoflurane (2%)/oxygen mix and positioned in a custom-built stereotactic frame with heads immobilized using ear bars.…”

“…Body temperature was maintained at 37 C ± 0.5 C using a heat mat (CWE, Inc.), and temperature was monitored by a mouse rectal temperature probe throughout surgery and imaging. Under a dissecting stereoscope (Leica), scissors (Fine Science Tools) were used to remove skin from the top of the head, then connective tissue was removed to expose the skull, followed by partial decerebration surgery to obtain optical access to the trigeminal ganglion (Hu 2019). The cranium was repeatedly washed and bathed in HEPES buffer (160 mM NaCl, 6 mM KCl, 13 mM glucose, 13 mM HEPES, 2.5 mM CaCl 2 , 2.5 mM MgCl 2 with pH adjusted to 7.2 using 10N NaOH).…”

Visualization of trigeminal ganglion sensory neuronal signaling regulated by Cdk5

“…Body temperature was maintained at 37℃ ± 0.5℃ using a heat mat (CWE, Inc.), and temperature was monitored by a mouse rectal temperature probe throughout surgery and imaging. Under a dissecting stereoscope (Leica), scissors (Fine Science Tools) were used to remove skin from the top of the head, then connective tissue was removed to expose the skull, followed by partial decerebration surgery to obtain optical access to the trigeminal ganglion (Hu 2019). The cranium was repeatedly washed and bathed in HEPES buffer (160 mM NaCl, 6 mM KCl, 13 mM glucose, 13 mM HEPES, 2.5 mM CaCl2, 2.5 mM MgCl2 with pH adjusted to 7.2 using 10N NaOH).…”

Ultrasound localization microscopy and functional ultrasound reveal atypical features of the live trigeminal ganglion

“…Despite the cellular resolution of these surrogates, this approach lacks the ability to follow the dynamics of these neuronal changes. Recently, the visualization of trigeminal sensory neuron activities in response to orofacial stimuli was reported ex-vivo using either voltage sensitive dye approach in decerebrated animals (9) or calcium imaging in GCaMP6 mouse line (10,11). However, these experimental paradigms used were highly invasive requiring the decerebration of the animal, and therefore the disconnection between TG and the CNS.…”