3 research outputs found
Effects of Cultured Adrenal Chromaffin Cell Implants on Hindlimb Reflexes of the 6-OHDA Lesioned Rat
The effects of implantation of cultured
adrenal medullary cells on the recovery of
neurotransmitter specific reflex activity were
studied in the rat spinal cord using electrophysiological
testing methods. Cell suspensions
of cultured neonatal adrenal medullary
chromaffin (AM) cells (which produce
catecholamines), or Schwann (Sc) cells (controls)
were implanted into the lumbar region of the
spinal cord 2 weeks after catecholamine (CA)
denervation by intracisternal injection of 6-hydroxydopamine
(6-OHDA). All cells were
taken from 7 day neonates and cultured for 10
days in the presence of nerve growth factor
(NGF). Three months after implantation, the
extent of implant-associated recovery of reflex
activity was determined by measuring electromyogram
(EMG) activity and force associated
with the long latency component of the hindlimb
withdrawal reflex (which is CA modulated).
After the electrophysiological testing, rats were
anesthetized, and the spinal cords were rapidly
removed and frozen. Spinal cords were sectioned
longitudinally, and implanted cells were
visualized using glyoxylic acid techniques.
Labelled sections were examined to determine
cell survival. Results indicate that 1) chromaffin
cells survive for 3 months in the segments of the
cord into which they have been implanted and
2) rats implanted with AM cells have
significantly more forceful withdrawal reflexes
than those that received Sc cells or received no
implant after lesioning