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ABSTRACT: Chemosensory-based communication is a vital signaling tool in most species, and evidence has recently emerged in support of the notion that humans also use social chemosignals (so-called pheromones) to communicate. An ongoing controversy does exist, however, concerning the receptor organ through which these chemicals are processed. There is a widespread belief that the vomeronasal organ (VNO) is responsible for processing social chemosignals in humans. Here we demonstrate that functional occlusion of the VNO does not change the percept of, sensitivity toward, or functional neuronal processing of a putative human pheromone. Perithreshold and suprathreshold perception of the endogenous chemical androstadienone (AND) were compared, as were positron emission tomography brain activations evoked by AND when the VNO was either occluded or left open. In addition, we compared sensitivity to AND in subjects with an identifiable VNO to those in whom no VNO could be detected. Thus we could examine the effects of the VNO at several different levels of processing. Occlusion or absence of the VNO did not affect either the perceptual measurements or the functional processing of the putative human pheromone, AND. These results provide strong evidence that the human VNO has no obvious function. Pheromonal communication in humans may be conveyed via the main olfactory system.
Human Brain Mapping 03/2011; 32(3):450-60. · 5.88 Impact Factor
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Athanasios Katsarkas
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ABSTRACT: Dizziness and vertigo occur frequently in aging. Inner ear or nervous system pathology (central or peripheral) may be the cause. Other causes may also be cardiovascular disease, medication, leg pathology, psycho-pathologic processes (psychogenic dizziness), etc. In our Dizziness Clinic, 3427 patients 70 years of age or older were evaluated and an accurate diagnosis was possible in 76.25 percent of cases. Dizziness specific to aging was not identified, although at times dizziness was more serious than in younger patients due either to weakness because of aging or to more than one cause of dizziness. Thus dizziness and vertigo in aging have to be investigated carefully and similarly to other age groups. To this effect, the history, the clinical examination, and the follow-up are the most essential tools available to the practicing physician.
Geriatrics 12/2008; 63(11):18-20. · 1.35 Impact Factor
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ABSTRACT: In previous studies, electromyographic potentials, recorded in response to auditory clicks, have been attributed to stimulation of the otolith (saccule) and have been termed vestibular evoked myogenic potentials (VEMPs). In this study, we assessed the VEMPs in subjects with normal auditory brainstem evoked responses, with no history of vestibular symptoms or neck and other skeletal muscle abnormalities. To this effect, 32 subjects (64 ears), after ethics committee approval, were exposed to 75, 150, and 300 clicks at 100 dB, and the responses were averaged. Electromyographic activity was recorded by applying surface electrodes over the sternocleiodomastoid muscle under the following three conditions: no muscle contraction/no clicks, muscle contraction/no clicks, and muscle contraction/clicks. Our findings suggest that electromyographic responses have to be obtained, during muscle contraction, first without and then with clicks. Our data also suggest that comparison of these two recordings is necessary for meaningful results.
The Journal of otolaryngology 05/2002; 31(2):93-6. · 0.50 Impact Factor
