Repetitive Vocalizations Evoked by Local Electrical Stimulation of Avian Brains

Abstract

The brains of 22 anesthetized chickens were systematically explored with stimulating electrodes for electrically-evoked vocalizations. Both active and inactive areas for evoked vocalizations as determined from 821 electrode penetrations were plotted. An apparently continuous system, active for vocalization, extends from the preoptic region rostrally to the most caudal portion of the medulla posteriorly. All portions of the striatum and spinal cord sampled were negative for vocalizations at the stimulus intensity used. Thresholds were lowest; calling was the most natural sounding and was elicited in the absence of other behavior in the area ventro-medial to the inferior colliculus. Most of the brain yielded only repetitive vocalizations ranging from brief ''cuk'' sounds to longer duration squawk sounds similar to those given by normal chickens. In the medulla both repetitive sounds in response to continuous stimulation and single protracted sounds per stimulation were evoked. Both types of vocalization could be elicited from the same site by varying the stimulus intensity. In portions of the midbrain, pons and medulla vocalization substrates corresponded to areas reported to yield respiratory responses in this and other species. Results are in agreement with those reported for chronically-implanted awake birds and are interpreted to suggest a single set of neural mechanisms controlling the production of vocalizations.

Projections of the dorsomedial nucleus of the intercollicular complex (DM) in relation to respiratory-vocal nuclei in the brainstem of pigeon (Columba livia) and zebra finch (Taeniopygia guttata)

“…It has long been known that electrical stimulation of certain regions of the avian midbrain, collectively known as the ''midbrain call area,'' can elicit vocalizations (e.g., Popa and Popa, 1933;Lan, 1958;Brown, 1965Brown, , 1971Murphy and Phillips, 1967; Potash, 1970a,b;Delius, 1971;Peek and Phillips, 1971;Seller, 1980;Jahnke and Abs, 1982;Li and Lan, 1990). The most effective sites, i.e., those where vocalization can be elicited with the smallest amounts of current, correspond to a nuclear component of the intercollicular complex (ICo) in close proximity to rostral levels of the inferior colliculus, known as nucleus mesencephalicus lateralis, pars dorsalis (MLd).…”

Trilobite Eyes: Calcified Lenses in vivo

“…The presence of androgen-concentrating cells in the midbrain of the chaffinch is particularly interesting in view of the suggestion that the midbrain is involved in the control of vocal behavior in a number of avian species (19)(20)(21)(22)(23)(24)(25)(26)(27)(28). Popa and Popa (19) and Brown (20) reported that vocalizations could be electrically stimulated in an area near the optic ventricle.…”

Pattern Generator for Repetitive Avian Vocalization: Preliminary Localization and Functional Characterization

“…ESB was performed through a concentric electrode (0.13 mm in diameter stain less steel wire, enamel-insulated, inside 24-gauge hypodermic tubing, 0.5 mm bare tips) positioned in the low-threshold calling area of the midbrain, ventromedial to the nucleus mesencephalicus lateralis, pars dorsalis (for details of location and sti mulus parameters see Phillips el al., 1972;Peek and Phillips, 1971). A stainless steel wire, 25 ^m in diameter, insulated, and stiffened with a 000 insect pin, picked up extracellular unit spikes well.…”