Effects of adenosine on gabaergic synaptic inputs to identified ventrolateral preoptic neurons

Neuroscience. 2003;119(4):913-8. doi: 10.1016/s0306-4522(03)00246-x.


The ventrolateral preoptic nucleus (VLPO) is a key regulator of behavioral state that promotes sleep by directly inhibiting brain regions that maintain wakefulness. Subarachnoid administration of adenosine (AD) or AD agonists promotes sleep and induces expression of Fos protein in VLPO neurons. Therefore, activation of VLPO neurons may contribute to the somnogenic actions of AD. To define the mechanism through which AD activates VLPO neurons, we prepared hypothalamic slices from 9 to 12-day-old rat pups and recorded from 43 neurons in the galaninergic VLPO cluster; nine neurons contained galanin mRNA by post hoc in situ hybridization. Bath application of AD (20 microM) to seven of these neurons had no direct effect but caused a significant decrease in the frequency of spontaneous miniature inhibitory postsynaptic currents in the presence of tetrodotoxin, indicating a presynaptic site of action. We conclude that AD-mediated disinhibition increases the excitability of VLPO neurons thus contributing to the somnogenic properties of AD.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Adenosine / metabolism*
  • Adenosine / pharmacology
  • Afferent Pathways / cytology
  • Afferent Pathways / drug effects
  • Afferent Pathways / metabolism*
  • Animals
  • Animals, Newborn
  • Female
  • Galanin / genetics
  • Male
  • Neural Inhibition / drug effects
  • Neural Inhibition / physiology
  • Organ Culture Techniques
  • Preoptic Area / cytology
  • Preoptic Area / drug effects
  • Preoptic Area / metabolism*
  • Presynaptic Terminals / drug effects
  • Presynaptic Terminals / metabolism*
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Sleep / drug effects
  • Sleep / physiology
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology*
  • gamma-Aminobutyric Acid / metabolism*


  • RNA, Messenger
  • gamma-Aminobutyric Acid
  • Galanin
  • Adenosine