Fig 5. CB₁ immunoreactivity in the spinal cord, dorsal root ganglia and peripheral nerve.

In figure A, strong CB₁ immunoreactivity is shown in the grey matter of the cervical spinal cord of a six-month-old dog and the cytoplasm of ependymal cells lining the central canal (A; arrow). Within the dorsal horn, CB₁ immunoreactivity appears surrounding unstained neuronal bodies (B; arrow). In the cervical spinal cord of a ten-year-old dog notice slight immunoreactivity of the grey matter (C). Figure D showing the cervical dorsal root ganglia of a six-month-old dog with slight immunoreactivity of large neurons and strong CB₁ immunoreactivity of small dark neurons (arrows) and satellite cells (arrowheads). The thoracic dorsal root ganglia of a ten-year-old dog with moderate CB₁ immunoreactivity of small dark neurons and satellite cells, large neurons show slight immunoreactivity (E; arrow). The cervical dorsal root ganglia of a four-week-old dog depicting scattered large and small neurons and satellite cells with slight CB₁ immunoreactivity (F; arrow). In figure G the cervical spinal nerve of a six-month-old dog shows strong CB₁ expression in Schwann cells ensheating axons (arrow). Few Schwann cells show moderate CB₁ immunoreactivity (arrow) in a thoracic spinal nerve of a ten-year-old dog (H). The cervical spinal nerve in the four-week-old dog shows moderate CB₁ immunoreactivity of scattered Schwann cells (I; arrow). IHC was performed using the avidin-biotin-peroxidase complex (ABC) method.