Abstract
The distribution of synaptic terminals onto spinothalamic tract cells (types I and II) of the superficial dorsal horn was determined with special reference to the amino acid transmitters glutamate and γ‐aminobutyric acid. Fifteen spinothalamic cells retrogradely labeled from the thalamus with the neuroanatomical tracer wheatgerm agglutinin conjugated to horseradish peroxidase were sectioned for electron microscopy. Serial sections from several levels through each cell were immunostained for glutamate and γ‐aminobutyric acid using a postembedding immunogold technique. Perimeter measurements of spinothalamic cell somata and dendrites and the lengths of apposition for all terminal profiles in contact with the spinothalamic cells were obtained from electron micrographs using a digitizing tablet. These data were used to determine the density of terminals on the soma and dendrites. In addition, the terminal population on these cells was categorized by transmitter content (glutamate, γ‐aminobutyric acid, or unlabeled). The results demonstrate that terminal density increased on dendrites relative to their distance from the soma. Glutamatergic and GABAergic input composed 37% and 20% of the terminal population, respectively, and these percentages remained uniform for the soma and dendrites. There were no significant differences among the 15 cells analyzed for this study. The results, therefore, suggest that both type I and type II STT cells of the superficial DH have similar synaptic organizations. © 1995 Wiley‐Liss, Inc.
Original language | English (US) |
---|---|
Pages (from-to) | 417-428 |
Number of pages | 12 |
Journal | Journal of Comparative Neurology |
Volume | 361 |
Issue number | 3 |
DOIs | |
State | Published - Oct 23 1995 |
Externally published | Yes |
Keywords
- ascending systems
- immunogold
- lamina I
- nociception
ASJC Scopus subject areas
- General Neuroscience