Neural correlates of frog calling: preoptic area trigger of ?mating calling?

Abstract

1. The mating calling circuits of the leopard frog,Rana pipiens pipiens, can be triggered in an isolated brainstem by electrical stimulation of the anterior preoptic nucleus (Fig. 1). 2. The area most sensitive to stimulation was found to be in the ventral half of the nucleus and was at the lateral border of the preoptic gray (Figs. 2, 3). The ventricular surface was not sensitive to small amplitude stimuli. 3. Gross lesions showed that direct pathways at the ventrolateral border of the central gray, from the stimulation site to the isthmotrigeminal tegmentum, were adequate to trigger the mating calling pattern generator (Fig. 4). 4. A pathway crossing in the region of the ansulate commissure was also identified.