[Effects of systemic administration of strychnine, L-allylglycine, bicuculline and picrotoxin on the transsynaptic neural destruction in the medullary dorsal horn following transection of the rat inferior alveolar nerve].
Adult rats underwent unilateral transection of the inferior alveolar nerve and subsequent intraperitoneal injection of strychnine (1 mg/kg, 3-23 days) at various posttransectional intervals. When they were sacrificed at 18-30 days posttransectionally, many pyknotic neuronal cell bodies were observed in plastic embedded toluidine blue-stained 1 micron-thick sections of the medullary dorsal horn. They were mostly found in the dorsal part of the dorsal horn ipsilateral to the neurotomy and were more abundant in laminae I/II than in laminae III/IV. Similar pyknotic neurons were found after 1 or 2 days of L-allylglycine administration (55.7 mg/kg/day) at a posttransectional interval of 20 days. Unlike those observed after strychnine treatment, the pyknotic neurons after L-allylglycine treatment were evenly distributed throughout laminae I-IV of the dorsal half of the medullary dorsal horn. Twenty-three days of bicuculline (2 mg/kg/day) or picrotoxin (0.5 mg/kg/day) treatment at an interval of 7 days did not yield pyknotic neurons. The results are discussed in the light of intrinsic synaptic circuitry of the dorsal horn.
Takemura
M
M
2nd Department of Oral Anatomy, Osaka University, Faculty of Dentistry.
Sugimoto
T
T
Sakai
A
A
D000501:Allylglycine / Q000494:pharmacology*; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology*; D005998:Glycine / Q000031:analogs & derivatives*; D008297:Male; D008340:Mandibular Nerve / Q000502:physiology*; D008526:Medulla Oblongata / Q000473:pathology*; D009410:Nerve Degeneration / Q000187:drug effects*; D010852:Picrotoxin / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013331:Strychnine / Q000494:pharmacology*
D000501:Allylglycine; D001640:Bicuculline; D005998:Glycine; D010852:Picrotoxin; D013331:Strychnine