In 1917 D’Arcy Thompson observed that the pair of antlers of a red deer, a sambur or a wapiti Make up between them a single surface that is more or less spherical or occasionally an ellipsoidal surface. The palmated ...In 1917 D’Arcy Thompson observed that the pair of antlers of a red deer, a sambur or a wapiti Make up between them a single surface that is more or less spherical or occasionally an ellipsoidal surface. The palmated antlers of the moose are explored to provide an exam-ple of how antlers can be instrumental in lowering the threshold sensitivity of hearing.展开更多
Sensing the direction of origin of a sound in space has long been attributed to the delay between arrival times between the two ears. This, now discredited two dimensional theory, was put to rest by the observation th...Sensing the direction of origin of a sound in space has long been attributed to the delay between arrival times between the two ears. This, now discredited two dimensional theory, was put to rest by the observation that a person deaf in one ear can locate sounds in three dimensional space. We present here a new theory of sound localization that has the re-quired three dimensional measurement. It is a theory that interprets the well researched biological structure of the mammalian cochlea in a new and logical way, which leads to a deeper understanding of how sound localization functions.展开更多
When the processes of neurons are in close proximity they effectively couple to each other in a process termed Ephaptic coupling. This coupling occurs without the membranes touching when the space between them is some...When the processes of neurons are in close proximity they effectively couple to each other in a process termed Ephaptic coupling. This coupling occurs without the membranes touching when the space between them is some tens of nanometers. If the intra-membrane spacing has a mechanical bistability, which moves the membranes closer and further apart, the Ephaptic coupling will be turned on and off allowing one neuron to read, or not read the content of the other. This paper explores the possibilities of bistable ephaptic memory element by a study of an analogous system that operates at a much larger scale, the Stereocilia of the hair cell. Published measurement of hair cell Stereocilia force/displacement function shows both a negative slope region in the displacement function and tendency to express bistability. We show here how this negative slope region can arise through the exigency of colloid forces. An explanation of Colloid Theory, presented in a graphic form, shows how a colloid force function can be modified to match the measured hair cell cilia force function. The colloid force function is modified by a limiting function resulting from Stereocilia side links, structural details that tie together the hair cell Stereocilia clusters. Understanding how a limited, simple behavior such as Stereocilia bistability functions may point to a more general understanding of how bistability may underlie other areas of living organisms such as memory and computation.展开更多
Using an engineering perspective which is looking at the hair cells cilia as a total entity interacting with its neighboring cilia along their entire length, a theory of capacitive transduction is developed. This larg...Using an engineering perspective which is looking at the hair cells cilia as a total entity interacting with its neighboring cilia along their entire length, a theory of capacitive transduction is developed. This larger scaled view of cilia interaction suggests that transduction may be achieved through a mechanically controlled variable capacitor in the cilia bundle. A brief review of some seldom considered facts about electrical capacitors supports the hypothesis presented. Experimental measurements of hair cell reversal potential and ionic conditions surrounding the cilia during transduction, long reported in the biophysical literature, also support a capacitive hypothesis of transduction.展开更多
The acoustic sense of fish, embodied in the lateral line, no longer worked when amphibians ventured onto the land. The new acoustic environment where sound traveled in the thin medium of air rather than the relatively...The acoustic sense of fish, embodied in the lateral line, no longer worked when amphibians ventured onto the land. The new acoustic environment where sound traveled in the thin medium of air rather than the relatively dense medium of water presented a major challenge. The multiple sensors of the lateral line were replaced by one gross sensor, the tympanic membrane or eardrum. We show acoustical measurements on the turtle shell that can suggest a possible explanation of how the turtle dealt with the issue of sensing the directionality of incoming sounds.展开更多
文摘In 1917 D’Arcy Thompson observed that the pair of antlers of a red deer, a sambur or a wapiti Make up between them a single surface that is more or less spherical or occasionally an ellipsoidal surface. The palmated antlers of the moose are explored to provide an exam-ple of how antlers can be instrumental in lowering the threshold sensitivity of hearing.
文摘Sensing the direction of origin of a sound in space has long been attributed to the delay between arrival times between the two ears. This, now discredited two dimensional theory, was put to rest by the observation that a person deaf in one ear can locate sounds in three dimensional space. We present here a new theory of sound localization that has the re-quired three dimensional measurement. It is a theory that interprets the well researched biological structure of the mammalian cochlea in a new and logical way, which leads to a deeper understanding of how sound localization functions.
文摘When the processes of neurons are in close proximity they effectively couple to each other in a process termed Ephaptic coupling. This coupling occurs without the membranes touching when the space between them is some tens of nanometers. If the intra-membrane spacing has a mechanical bistability, which moves the membranes closer and further apart, the Ephaptic coupling will be turned on and off allowing one neuron to read, or not read the content of the other. This paper explores the possibilities of bistable ephaptic memory element by a study of an analogous system that operates at a much larger scale, the Stereocilia of the hair cell. Published measurement of hair cell Stereocilia force/displacement function shows both a negative slope region in the displacement function and tendency to express bistability. We show here how this negative slope region can arise through the exigency of colloid forces. An explanation of Colloid Theory, presented in a graphic form, shows how a colloid force function can be modified to match the measured hair cell cilia force function. The colloid force function is modified by a limiting function resulting from Stereocilia side links, structural details that tie together the hair cell Stereocilia clusters. Understanding how a limited, simple behavior such as Stereocilia bistability functions may point to a more general understanding of how bistability may underlie other areas of living organisms such as memory and computation.
文摘Using an engineering perspective which is looking at the hair cells cilia as a total entity interacting with its neighboring cilia along their entire length, a theory of capacitive transduction is developed. This larger scaled view of cilia interaction suggests that transduction may be achieved through a mechanically controlled variable capacitor in the cilia bundle. A brief review of some seldom considered facts about electrical capacitors supports the hypothesis presented. Experimental measurements of hair cell reversal potential and ionic conditions surrounding the cilia during transduction, long reported in the biophysical literature, also support a capacitive hypothesis of transduction.
文摘The acoustic sense of fish, embodied in the lateral line, no longer worked when amphibians ventured onto the land. The new acoustic environment where sound traveled in the thin medium of air rather than the relatively dense medium of water presented a major challenge. The multiple sensors of the lateral line were replaced by one gross sensor, the tympanic membrane or eardrum. We show acoustical measurements on the turtle shell that can suggest a possible explanation of how the turtle dealt with the issue of sensing the directionality of incoming sounds.
