Abstract
Intrinsic sensitization is a form of behavioral facilitation that is distinct from the extrinsic sensitization normally studied. To examine whether intrinsic and extrinsic sensitization are mediated by different physiological processes, the effects of 5,7-dihydroxytryptamine-induced serotonin (5-HT) depletion on intrinsic sensitization of the leech whole-body shortening response were observed. Previous experiments have shown that 5-HT depletion disrupts dishabituation and extrinsic sensitization of this behavior in the leech. Intrinsic sensitization was observed in preparations from both control and 5-HT-depleted animals, indicating that this form of behavioral facilitation was not affected by 5-HT depletion. The differences in the effects of 5-HT depletion on intrinsic versus extrinsic sensitization suggest that there are distinct neurophysiological processes mediating these two forms of behavioral facilitation. In addition, 5-HT depletion appeared to disrupt a putative extrinsic form of habituation of the shortening reflex. These data support the hypothesis that both intrinsic and extrinsic processes of neuromodulation mediate habituation and sensitization.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 509-520 |
| Number of pages | 12 |
| Journal | Learning and Memory |
| Volume | 6 |
| Issue number | 5 |
| DOIs | |
| State | Published - 1999 |
| Externally published | Yes |
ASJC Scopus subject areas
- Neuropsychology and Physiological Psychology
- Cognitive Neuroscience
- Cellular and Molecular Neuroscience