Effect of PGE2 on preoptic and anterior hypothalamic neurons using brain slice preparation.

In the present study, effects of prostaglandin (PG) E2 on the hypothalamic neurons were investigated using slice preparations of rats. Warm- (57%) and cold-responsive (33.3%) and thermally insensitive (42.3%) neurons were facilitated by PGE applied in a culture chamber. Some neurons (5.1%) showed inhibitory response to PGE2. The remaining neurons did not show any responsiveness to PGE2. Moreover, we also examined the effects of PGE2 on the hypothalamic neurons both in normal Krebs-Ringer solution and synaptic blocking medium (low Ca2+, high Mg2+). Most of the neurons (12/15) retained their responsiveness to PGE2 in the synaptic blocking medium, indicating that PGE2 has a direct action on the hypothalamic neuron. Therefore, it is conceivable that neurons in the preoptic and anterior hypothalamic region that respond to PGE2 might play an important role in the development of fever. However, characteristics of neurons responding to PGE2 were not determined based on their thermoresponsiveness.