Excitation of neurons in the canine area postrema by prostaglandins.

The effects of prostaglandins on electrical activity of neurons in the canine area postrema were studied using the techniques of extracellular recording with iontophoresis. Excitatory responses were obtained upon application of prostaglandins A1, B1, B2, E1, F1 alpha, and F2 alpha in between 24 and 50% of the cells studied. The excitation was very similar in pattern to that observed to apomorphine, biogenic amines, and several neuropeptides in that it had a relatively long latency, low maimal frequency, and prolonged duration. Since the area postrema is known to play a central receptive role in initiating emesis to circulating toxins, these results suggest that prostaglandins may play a role in the initiation of some forms of emesis.