Effect of synaptic blockade on thermosensitive neurons in hypothalamic tissue slices

Am J Physiol. 1982 Nov;243(5):R480-90. doi: 10.1152/ajpregu.1982.243.5.R480.


To understand the basis of hypothalamic neuronal thermosensitivity, single-unit activity was recorded in vitro, from constantly perfused tissue slices of rat preoptic area and anterior hypothalamus, PO/AH. The firing rate and thermosensitivity of individual PO/AH neurons was determined before, during, and after tissue perfusion with a synaptic blocking medium, containing elevated magnesium and decreased calcium concentrations. During synaptic blockade, thermosensitivity was retained in nearly all of the warm-sensitive neurons, and some temperature-insensitive neurons showed increased warm sensitivity. The thermosensitivity of all cold-sensitive neurons was lost during synaptic blockade. These results support the hypothesis that PO/AH cold-sensitive neurons depend on synapses from nearby warm-sensitive neurons for their temperature sensitivity; whereas warm sensitivity is an independent property of certain PO/AH neurons.

Publication types

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

MeSH terms

  • Animals
  • Calcium / pharmacology
  • Electric Conductivity
  • Hypothalamus, Anterior / drug effects
  • Hypothalamus, Anterior / physiology*
  • In Vitro Techniques
  • Magnesium / pharmacology
  • Male
  • Neurons / drug effects
  • Neurons / physiology*
  • Preoptic Area / physiology*
  • Rats
  • Rats, Inbred Strains
  • Synapses / drug effects
  • Synapses / physiology*
  • Temperature


  • Magnesium
  • Calcium