Accession Number : AD0721466

Title :   Chemical Mechanisms and Neural Coding in Vertebrate Chemosensors.

Descriptive Note : Final rept. Mar 67-Aug 70,

Corporate Author : NORTHWESTERN UNIV EVANSTON ILL DEPT OF BIOLOGICAL SCIENCES

Personal Author(s) : Gesteland,Robert C.

Report Date : FEB 1971

Pagination or Media Count : 105

Abstract : Studies were undertaken to discover the nature of the neural code which transmits chemoreceptor information and the molecular principles of chemoreceptor cell function. In the vertebrate nose odor intensity is coded by average pulse rate, the rate inversely proportional to stimulus intensity. Odor kind is coded by pulse intervals in the signal. The result is a detection and signalling system with maximum discrimination for weak signals and large information content with low pulse rates. Studies on a nose operating under a flowing water stream show that many substances which do not smell are adequate stimuli. Therefore it is not possible to infer olfactory receptor chemistry from knowledge of the chemical properties which distinguish odorous substances from non-odorous ones, as is commonly proposed. Repeated stimulation of a receptor cell yields results best explained by a process of strong bond formation between stimulus and receptor which does not break when stimulation ceases. Experiments with specific blocking substances indicate that the olfactory receptor sites are proteins. An experimental way to separate voltages due to chemoreceptor action from those due to electrochemical events in extracellular fluid has been found. Most important, an animal was found with large olfactory and taste receptor cells and have developed a preparation which allows intracellular microelectrode studies on these cells. (Author)

Descriptors :   (*CHEMORECEPTORS, *ELECTROPHYSIOLOGY), (*BIOCHEMISTRY, CHEMORECEPTORS), END ORGANS, SENSE ORGANS, SENSES(PHYSIOLOGY), TASTE, SMELL, NOSE(ANATOMY), NERVOUS SYSTEM, CENTRAL NERVOUS SYSTEM, STIMULATION(PHYSIOLOGY), PHYSIOLOGY, AMPHIBIANS, EXPERIMENTAL DATA, ODORS

Subject Categories : Biochemistry
      Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE