Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Crustacean mechanosensory neurons, isolated by enzymatic digestion from abdominal muscle receptor organs of Homarus americanus and Procambarus clarkii, maintain characteristic morphological and electrophysiological phenotypes in culture. New outgrowth occurs at both the axonal and dendritic poles. The patterns of outgrowth are distinct and in keeping with the sensory function. The cut axonal end gives rise to few elongated processes which rarely branch. In contrast, the new growth at the dendritic pole consists of multiple, short ($<$10 um) processes which resemble normal sensory termini. Cultured tonic and phasic sensory neurons respond to depolarizing current injections with characteristic firing patterns. Single channel patch clamp studies have identified at least four different ion channels. In Homarus, three channel types are voltage but not stretch sensitive. One channel type identified in Procambarus, displays both voltage and stretch sensitivity. These cultured mechanosensory neurons have the potential to be useful models for the study of the mechanisms of mechanotransduction.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

No description available.

Tactile sensation is a complex manifestation of mechanical stimuli applied to the skin. At the most fundamental level of the somatosensory system is the cutaneous mechanoreceptor, making it the logical starting point in the bottom-up approach to understanding the somatosensory system and sensation, in general. Unfortunately, a consensus has not been reached in terms of the afferent behavior of mechanoreceptors subjected to compressive stimulation. In this study, several afferent mechanoreceptors were isolated, mechanically stimulated with controlled compressive loads. Their responses were recorded and the sensitivities of the individual receptors to compressive stimulation were statistically evaluated by correlating the compressive state of the skin to the observed“all-or-nothing" responses. A host of linear techniques have been employed previously to describe this multiple-input, binary-output system; however, each of these techniques has associated shortcomings when employed in this context. In particular, two shortcomings are the assumption of linear system input-output and the inability of the model to assess individual input-output associations relative to concurrent input in a multivariate context with interacting input. Therefore, a non-linear regression technique called logistical regression was selected for characterizing the mechanoreceptor system. From this model, the relative contributions that each component of the stimulus has upon the neural response of the receptor can be quantitatively assessed and extrapolated to the greater population of cutaneous mechanoreceptors. Since this study represents a novel approach to receptor characterization, a framework for the application of logistical regression to the time-series representation of the multiple-input, binary-output mechanoreceptor system was established and validated. Subsequently, in-vitro experiments were performed in which the afferent behavior of tactile receptors in rat hairy skin were recorded and the relative association between a number of biologically meaningful stimulus metrics and the observed neural response was evaluated for each receptor. Through the application of logistical regression, it was determined that cutaneous mechanoreceptors are preferentially sensitive to the rate of change of compressive stress when force-control stimulated and both stress and its rate of change when position-control stimulated.

by Chan Eliza. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 90-95). / ACKNOWLEDGEMENTS --- p.i / ABSTRACT --- p.ii / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter CHAPTER 2 --- LITERATURE REVIEW / Chapter SECTION 1 --- Classification of cutaneous mechanoreceptors in the mammalian skin --- p.3 / Chapter 1.1 --- Criteria --- p.3 / Chapter 1.2 --- Slowly adapting type I mechanoreceptors --- p.3 / Chapter 1.3 --- Rapidly adapting mechanoreceptors --- p.6 / Chapter SECTION 2 --- Structural features of Merkel cells --- p.8 / Chapter 2.1 --- History --- p.8 / Chapter 2.2 --- General morphology of Merkel cells --- p.8 / Chapter 2.3 --- Electron microscopical description of the Merkel cell-neurite complexes --- p.10 / Chapter SECTION 3 --- Responsive features of Merkel cell as slowly adapting type I mechanoreceptors --- p.12 / Chapter 3.1 --- History --- p.12 / Chapter 3.2 --- Principles of the in-vivo and in-vitro techniques --- p.13 / Chapter 3.2.1 --- Location of Merkel cells --- p.13 / Chapter 3.2.2 --- Characteristic firing pattern of the slowly adapting type I mechanoreceptor --- p.14 / Chapter SECTION 4 --- Functional implications of the Merkel cell --- p.18 / Chapter 4.1 --- An analogy between Merkel cells and sensory hair cells of the auditory system --- p.18 / Chapter 4.1.1 --- Sensory hair cells of the acoustico-lateralis system --- p.18 / Chapter 4.1.2 --- Mechano-electrical activity of the Merkel cells --- p.21 / Chapter 4.2 --- Existence of dense-core vesicles --- p.21 / Chapter 4.2.1 --- Hypoxia reduced excitability of slowly adapting type I mechanoreceptors --- p.23 / Chapter 4.2.2 --- Calcium blockers affect the responsiveness of the slowly adapting type I mechanoreceptors --- p.24 / Chapter 4.3 --- Met-enkephalin as a putative neurotransmitter --- p.25 / Chapter SECTION 5 --- Met-enkephalin as an endogenous opioid peptide --- p.26 / Chapter 5.1 --- Synthesis and metabolic regulation of met-enkephalin --- p.26 / Chapter 5.2 --- The opioid receptors --- p.27 / Chapter 5.3 --- "Selective μ-, δ- and kappa- opioid receptor antagonists" --- p.28 / Chapter CHAPTER 3 --- METHODS / Chapter SECTION 1 --- In-vitro study --- p.30 / Chapter 1.1 --- Dissection --- p.30 / Chapter 1.2 --- Identification of a receptor and administration of chemicals --- p.34 / Chapter 1.2.1 --- Firing patterns of the type I and type II mechanoreceptors --- p.35 / Chapter 1.2.2 --- Interspike interval distributions (ISI) --- p.37 / Chapter 1.3 --- Administration of drugs --- p.39 / Chapter SECTION 2 --- Experimental setup --- p.39 / Chapter 2.1 --- Mechanical stimulation --- p.39 / Chapter 2.2 --- Recordings --- p.40 / Chapter 2.3 --- Data processing --- p.41 / Chapter SECTION 3 --- Preparation of drugs --- p.43 / Chapter 3.1 --- Mu- opioid receptor antagonists --- p.43 / Chapter 3.2 --- Delta- opioid receptor antagonist --- p.43 / Chapter 3.3 --- Kappa- opioid receptor antagonists --- p.44 / Chapter SECTION 4 --- Data analysis --- p.44 / Chapter 4.1 --- Comparison of data --- p.44 / Chapter 4.2 --- Statistics --- p.45 / Chapter CHAPTER 4 --- RESULTS / Chapter SECTION 1 --- Determination of an optimal stimulation force --- p.46 / Chapter SECTION 2 --- Effects of the mu- opioid receptor antagonists --- p.48 / Chapter 2.1 --- Naloxone --- p.48 / Chapter 2.2 --- β-FNA --- p.54 / Chapter 2.2.1 --- Slowly adapting type I mechanoreceptor --- p.54 / Chapter 2.2.2 --- Control study of vehicle --- p.54 / Chapter SECTION 3 --- Effects of the delta- opioid receptor antagonist ICI174864 --- p.58 / Chapter SECTION 4 --- Effects of the kappa- opioid receptor antagonists --- p.58 / Chapter 4.1 --- nor-BNI --- p.58 / Chapter 4.1.1 --- Slowly adapting type I mechanoreceptor --- p.58 / Chapter 4.1.2 --- Afferent nerve attached to the type I mechanoreceptor --- p.62 / Chapter 4.2 --- MR2266 --- p.65 / Chapter 4.2.1 --- Control study of vehicle --- p.67 / Chapter 4.2.2 --- Slowly adapting type I mechanoreceptor --- p.67 / Chapter 4.2.3 --- Afferent nerve attached to the type I mechanoreceptor --- p.73 / Chapter CHAPTER 5 --- DISCUSSION AND CONCLUSION / Chapter SECTION 1 --- Study of the slowly adapting type I mechanoreceptors using the in-vitro preparation --- p.80 / Chapter 1.1 --- Characteristic features of the slowly adapting type I mechanoreceptor --- p.81 / Chapter 1.2 --- Optimal force of stimulation --- p.82 / Chapter SECTION 2 --- Effects of the opioid receptor antagonists --- p.82 / Chapter 2.1 --- Lack of effects of the μ- and δ- opioid receptor antagonists --- p.83 / Chapter 2.2 --- The kappa- opioid receptor antagonists --- p.85 / Chapter 2.2.1 --- nor-BNI --- p.85 / Chapter 2.2.2 --- MR2266 --- p.86 / Chapter SECTION 3 --- Existence of opioidergic receptor sites in the Merkel cell-neurite complexes ？ --- p.87 / REFERENCES --- p.90

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: cutaneous mechanoreceptors, logistical regression. Includes bibliographical references (p. 156-159).

Thesis (Ph. D.)--University of Adelaide, 2004. / Title from title screen. Description based on contents viewed Apr. 21, 2005. Includes bibliographical references.

Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Robert F. Rogers, Dept. of Electrical & Computer Engineering. Includes bibliographical references.

Call number: LD2668 .T4 1978 K84 / Master of Science