Response properties of diencephalic neurons to visual, acoustic and hydrodynamic stimulation in the goldfish, Carassius auratus

We studied the responses to sensory stimulation of three diencephalic areas, the central posterior nucleus of the dorsal thalamus, the anterior tuberal nucleus of the hypothalamus, and the preglomerular complex. Units sensitive to acoustic (500 Hz tone burst), hydrodynamic (25 Hz dipole stimulus) and visual (640 nm light flash) stimuli were found in both the central posterior and anterior tuberal nucleus. In contrast, unit responses or large robust evoked potentials confined to the preglomerular complex were not found. In the central posterior nucleus, most units were unimodal. Many units responded exclusively to visual stimulation and exhibited a variety of temporal response patterns to light stimuli. In the anterior tuberal nucleus of the hypothalamus, most units responded to more than one modality and showed a stronger response decrement to stimulus repetitions than units in the central posterior nucleus. Our data suggest that units in the central posterior nucleus are primarily involved in the unimodal processing of sensory information whereas units in the anterior tuberal nucleus of the hypothalamus may be involved in multisensory integration.