MAPPING OF WHISKER SENSORY INPUT IN THE TRIGEMINAL GANGLION OF THE

MOUSE

Stephanie RedmondDavid W. MatthewsDr. David Kleinfeld

University of California, San Diego

Mapping the Trigeminal Ganglion

• Where is the trigeminal ganglion (TG)?• What makes up the TG?• Whisker follicle injections• Image analysis• TG patterning• Going forward

Adapted from Kleinfeld, et al. 2008

Where is the TG?

Adapted from Kleinfeld, et al. 2006

What makes up the TG?

• Many different cell types– Whisker sensory neurons– Temperature-sensing neurons– Motor (movement) neurons

• Functions– Correlations to vision

• Hyperacuity– Trigeminal neuralgia

• Blood vessels rub against TG cells

R

M

L

C

rostral (R), caudal (C), lateral (L), medial (M)

Why should spatial organization exist?

TG Studies:• Anatomy • Gene Expression

Adapted from Waite 1992 Adapted from Hodge 2007

Whisker Follicle Injections

• Fluorescent retrograde neuron labeling– Alexa Fluor® Cholera Toxin Subunit B– Wild type mice, age ~P16

• TG histological slice– 50 to 75 micrometer slices

488 nm

555 nm

647 nm

Image Analysis

• Confocal Microscopy• Image through sample (~50-100 um)• Develop image stacks

"Confocal Microscopy", D Semwogerere & ER Weeks, published in the Encyclopedia of Biomaterials and Biomedical Engineering, Taylor & Francis (2005).

Screen with pinhole

Focal Point

Sample EA (488) B (555) C (647)

R

M

L

C

Image Analysis• Spatial Organization

• Measure cell height, width, length• Calculate and compare average:

• Position, volume

A (488) B (555) C (647)

R

M

L

C

TG Patterning

_x0001_A _x0001_B _x0001_C _x0001_D _x0001_E0

200

400

600

800

1000

1200

Average Cell Cross-sectional Area

12345

Whisker

Squa

re M

icrom

eter

s

Going Forward• Process image data

• Investigate other patterns• Average X-coordinate• Average Y-coordinate• Average volume

• Finish thesis paper

• Graduate

Acknowledgments

David W. MatthewsDr. David KleinfeldThe Kleinfeld LabPhysics REU ProgramUCSD

MPS FacultyProfessor ShilepskyProfessor Heinekamp

MPS MajorsWells College