State-dependent release of acetylcholine in rat thalamus measured by in vivo microdialysis

• DOI: 10.1523/jneurosci.14-09-05236.1994
• Publication Date: 2018-04-02T17:30:24Z
• Authors: JA Williams; J Comisarow; J Day; HC Fibiger; PB Reiner
• Keywords: Microdialysis; Tegmentum

Mesopontine cholinergic neurons have long been thought to play a key role in behavioral state control. In particular, they implicated the process of EEG desynchrony and generation rapid eye movement (REM) sleep. However, profile identified mesopontine has not unequivocally demonstrated. an attempt address this issue, vivo microdialysis was used monitor acetylcholine (ACh) release across rat thalamus, major projection site neurons. Because REM periods rats are short duration, method developed collect accumulate sufficiently large samples from each individual states wake, slow-wave sleep, sleep permit off-line analysis via (HPLC-ECD). Probe placement source innervation vicinity probe were verified using retrograde tracing combined with ChAT immunohistochemistry. Finally, sodium calcium dependence ACh measured thalamus tested TTX calcium-free dialysates. The results showed that (1) extracellular concentrations high during both wake significantly lower (2) majority projections dialysis probes originate tegmentum, (3) is due sodium- calcium-dependent mechanisms. contrast predictions some previous hypotheses, these demonstrate active