Effects of prostaglandin E2 on the activity of thermosensitive and insensitive single units in the preoptic/anterior hypothalamus of unanesthetized rabbits.

Toe eliminate depressant effects of anesthetics on neuron activity, we recorded the single unit activity of thermoregulatory neurons in the POAH of unanesthetized rabbits. Intraventricularly applied PGE2 induced consistent excitatory effects (190% increase in firing rate) on cold-excitable cells and inhibited the firing rate (50%) of warm-sensitive neurons. Single units that were insensitive or had uncreelatable changes in firing rate with POAH temperature were either facilitated or inhibited by PGE2. The consistent effects of PGE2 on the thermoregulatory neurons found in this study support the proposal of PGE modulation of thermoregulatory neurons during the development of a fever.