Telencephalic bill projections in the Landes goose.

Abstract

Electrical activity of trigeminal central projection areas was recorded in anesthetized and chronic awake geese. Evoked potentials of telencephalic structures were studied after stimulation of the bill, quintofrontal tract (QF), and several telencephalic structures (nucleus basalis [Bas], neostriatum frontale [NF], paleostriatum augmentatum [PA], and neostriatum caudale [NC]). Short-latency evoked potentials were recorded in Bas after stimulation of the bill or QF; this finding is consistent with a direct connection between the main sensory trigeminal nucleus and Bas. Short- and long-latency evoked potentials were recorded in PA and NC after stimulation of the posterior QF. These potentials are concluded to be due to two different pathways: The shorter-latency response is produced by fibers leaving QF posteriorly, while the longer-latency response is derived from fibers traveling along QF, relaying first in Bas and then in NF. From Bas and NF, two pathways convey impulses to NC; only one is relayed in PA.