Eugene M. Taylor

Vocalization in rhesus monkeys: Conditionability

Three rhesus monkeys were individually trained to emit relatively prolonged calls in an experimental arrangement which required that intensity of each call be maintained within prescribed limits. Each animal learned to produce the calls when a stimulus signaled the appropriate occasion. Stimulus control over the calls was demonstrated by increased number of calls and increased average duration of calls when the signal was present, together with diminished number of calls when the signal was not present.

Analysis of central nervous system involvement in the microwave auditory effect

Abstract Nine cats were prepared for the recording of potentials in 3 brain sites evoked by acoustic and microwave stimuli. Loci in which potentials were observed were eighth cranial nerve, medial geniculate nucleus and primary auditory cortex. The effect of cochlear disablement on these potentials was evaluated. Potentials at all sites were abolished by cochlear damage. There were no differences between acoustic and microwave stimuli in this regard. Data are interpreted as supporting the contention that the microwave auditory effect is mediated at the periphery as are the effects of conventional acoustic stimuli.

Amiloride sensitivity of the chorda tympani response to sodium chloride in sodium-depleted Wistar rats.

Peripheral gustatory mechanisms that may contribute to the expression of sodium (Na) appetite have been a focus of interest for many years. Because amiloride-sensitive Na transport is involved in the generation of neural signals in response to NaCl stimulation, the present study assessed whether changes in amiloride sensitivity of the neural response to NaCl accompany the induction of a Na appetite in the rat. Na deprivation was achieved by acute depletion with the diuretic furosemide. The magnitude of the whole-nerve chorda tympani response to 0.5 M NaCl was reduced in Na-depleted, compared with Na-replete, rats, which provides qualified support for previous reports that the induction of a Na appetite is associated with reduced neural responses to NaCl. However, changes in sensitivity to the specific Na channel blocker amiloride hydrochloride as a result of Na depletion were not evident. These findings suggest that the behavioral and neural changes that occur after Na depletion are not based on changes in amiloride sensitivity in the taste bud.

Microwave Interaction with the Auditory Systems of Humans and Cats

Recordings from elements of the auditory system of cats in response to pulsed microwaves, as well as determinations of thresholds of audibility of humans to the pulses indicate that an auditory sensation may be elicited by pulse energies >20 /spl mu/J/cm/sup 2/, regardless of average or peak power.

SOME EFFECTS OF ELECTROMAGNETIC RADIATION ON THE BRAIN AND SPINAL CORD OF CATS

The central nervous system has received particular attention in the appraisal of possible effects of electromagnetic energy on biologic entities. This concern has numerous bases with face validity. Because it is well known that the basic function of the nervous system, generation and propagation of signals, is dependent on a generally well-understood complex of electrical and electrochemical processes, it is first a t least plausible that electromagnetic fields established by microwave irradiation, or by any means, could interfere with these mechanisms. Second, many studies, particularly in the Soviet Union and in Eastern European laboratories, have attributed general organismic response to electromagnetic radiation to effects exerted upon the central nervous s y ~ t e m . ~ Finally, some Western work implicates the central nervous system in microwave-evoked effects. Particularly noteworthy is the work of Frey and Messenger,s Guy and associates: and others that indicates microwave interaction with the auditory system. The effects considered relative to these bases are taken to be quite different from electromagnetic radiation-induced temperature elevation of the nervous tissue, that is, that the former are specific irradiation effects. Unfortunately, each of these bases has features that detract from its plausibility. Substantial data are not available to support the idea that external fields are effective in perturbing basic nervous system processes. The Soviet work has been characterized by two features that limit its acceptance as definitive information: procedural detail has been so lacking in the published reports that the findings are difficult to e ~ a l u a t e , ~ and the purported effects are based on nonspecific functional changes in which the nervous system can be implicated only through numerous equivocal assumptions. The role of central nervous system involvement in auditory perception of microwaves is an unresolved question. There is evidence that this effect is exerted in much the same mode as that of ordinary acoustic stimuli1° and that it does not act upon the central nervous system. In any event, these considerations and questions have stimulated interest to further investigate possible nervous system effects. We believe that an appropriate approach is to study the behavior of identifiable nervous system entities exposed to quantified electromagnetic energy. Early work in this laboratory involved controlled irradiation of cat heads and observation of

Somatic reflex development in infant macaques.

Thirty infant monkeys have been tested on a protocol of 19 measures of somatic reflex development. The sample includes four cesarean-derived premature infants of 150-160 days gestational age, and 26 term infants ranging in age from four to 48 days.

Microwave Effects on Central Nervous System Attributed to Thermal Factors

Microwave-produced changes in CNS-evoked potentials appear limited to thermal effects, as evidenced by 1) similar changes being elicited by equivalent non-radiation heating, and 2) reduction or even reversal of radiation effects with concurrent brain cooling.

Infant primate larynx: developmental histology

Laryngeal epithelium of monkeys (M. mulatta, M. nemestrina) ranging in age from late fetal to adult was found to undergo the following developmental changes: (1) progressive elaboration of commissural epithelium prenatally, reaching the adult form of pseudostratified columnar ciliated epithelium early in the postnatal period;(2) vocal process epithelium changing from cuboid to stratified squamous tissue during the late prenatal period, and (3) progressive increments in overall epithelial thicknees during development, reaching a maximum in the early postnatal period. Chondrocyte density of the cricoid and thyroid cartilage decreased during the late prenatal period, reaching the adult form at the neonatal stage. The evidence suggests that mechanical or metaplastic stresses do not determine the observed tissue changes.

Isometric force control by human tongue and forefinger

Abstract The performance of the tongue and forefinger in two isometric force tracking tasks was studied. Tracking a sine-wave force was done more effectively than tracking a square-wave force, using either finger or the tongue. Finger tracking performance proved to be consistently better than tongue tracking in either task.