Effects of glutamate and gamma-aminobutyric acid on spontaneously active intraocular spinal cord graft neurons.
Pieces of fetal rat lumbar spinal cord were transplanted into the anterior eye chamber of adult rat hosts. At least seven months later, extracellular single-unit recordings of spontaneously active graft neurons were made prior to and during the superfusion of either glutamate or gamma-aminobutyric acid (GABA). Superfusion of glutamate produced an increase (five cells), decrease (three cells), or had no effect (two cells) on the firing rate of neurons tested. Superfusion of GABA decreased the firing rate of all twelve neurons tested, while superfusion of the GABA receptor antagonist bicuculline increased the firing rates of all eight neurons tested. The latency and magnitude of the responses to glutamate and GABA were not related to depth of the recording electrode below the graft surface. Together, these data suggest that the intraocular spinal cord graft is suitable for the in vivo study of GABA and glutamate neuropharmacology.
Department of Neurological Surgery, School of Medicine, University of Miami, FL 33136.
J G
JG
Broton
R P
RP
Yezierski
A
A
Seiger
D000818:Animals; D000867:Anterior Chamber; D001640:Bicuculline / Q000031:analogs & derivatives / Q000494:pharmacology; D004594:Electrophysiology; D005260:Female; D016332:Fetal Tissue Transplantation; D005971:Glutamates / Q000494:pharmacology*; D018698:Glutamic Acid; D009474:Neurons / Q000637:transplantation*; D009799:Ocular Physiological Phenomena; D011247:Pregnancy; D051381:Rats; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology / Q000637:transplantation*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D005971:Glutamates; D018698:Glutamic Acid; C017069:bicuculline methiodide; D005680:gamma-Aminobutyric Acid; D001640:Bicuculline