Table 1.
Summary of the Effects of Various Recombinant apCAMs' Overexpression on 5-HT-Induced Long-Term Functional (EPSP) and Structural (Varicosity) Changes
| Long-term facilitation
|
||
|---|---|---|
| Overexpression | EPSP ↑ | Varicosity ↑ |
| In sensory neuron | ||
| TM-apCAM | No | No |
| GPI(S)-apCAM | Yes | Yes |
| GPI(L)-apCAM | Yes | N.D.a |
| Δcyto | Yes | Yes |
| Δextra | Yes | No |
| GFP-CYTO | Yes | No |
| MAP kinase mutant (T→A) | Yes | No |
| TM-apCAM, anti-HA Ab | Yes | No |
| In motor neuron | ||
| TM-apCAM | Yes | N.D. |
| GPI(S)-apCAM | Yes | N.D. |
Only full-length TM-apCAM overexpression in presynaptic SNs inhibited the 5-HT-induced increase of EPSP amplitude. However, overexpression of other apCAM mutant constructs had no effect on the increase of EPSP amplitude. The overexpression of DNA constructs containing the cytoplasmic domain of TM-apCAM (TM-apCAM, Δextra, GFP-CYTO, MAP kinase mutant (T→A), TM-apCAM, antiHA Ab) inhibited new varicosity formation by 5-HT treatment.
a
N.D.: Not determined.