5 Somatosensitivity, viscerosensititvity, proprioception and pain I Somatosensitivity, viscerosensititvity, proprioception and pain I2 The role of nervous system Somatosensitivity, viscerosensititvity, proprioception and pain I3 Input Integration Output REGULATIONREGULATION Potential input Potential output ANTICIPATIONANTICIPATION Sensor Effector Cortex Cortex Receptors/sensors Somatosensitivity, viscerosensititvity, proprioception and pain I4 • Energy convertor – Signal reception – Signal transformation • Receptor potential – Generator potential • Action potential • Adequate stimulus • Non adequate stimulus http://www.slideshare.net/CsillaEgri/presentations Receptor/generator and action potential Somatosensitivity, viscerosensititvity, proprioception and pain I5 http://www.slideshare.net/drpsdeb/presentations Receptors/sensors Somatosensitivity, viscerosensititvity, proprioception and pain I6 • Energy convertor – Signal reception – Signal transformation • Receptor potential – Generator potential • Action potential • Adequate stimulus • Non adequate stimulus http://www.slideshare.net/CsillaEgri/presentations Receptors/sensors Somatosensitivity, viscerosensititvity, proprioception and pain I7 • Energy convertor – Signal reception – Signal transformation • Receptor potential – Generator potential • Action potential • Adequate stimulus • Non adequate stimulus http://www.slideshare.net/CsillaEgri/presentations Receptors/sensors Somatosensitivity, viscerosensititvity, proprioception and pain I8 • Energy convertor – Signal reception – Signal transformation • Receptor potential – Generator potential • Action potential • Adequate stimulus • Non adequate stimulus http://www.slideshare.net/CsillaEgri/presentations Receptors/sensors Somatosensitivity, viscerosensititvity, proprioception and pain I9 • Energy convertor – Signal reception – Signal transformation • Receptor potential – Generator potential • Action potential • Adequate stimulus • Non adequate stimulus http://www.slideshare.net/CsillaEgri/presentations Receptors/sensors Somatosensitivity, viscerosensititvity, proprioception and pain I10 • Energy convertor – Signal reception – Signal transformation • Receptor potential – Generator potential • Action potential • Adequate stimulus • Non adequate stimulus http://www.slideshare.net/CsillaEgri/presentations Intensity coding Somatosensitivity, viscerosensititvity, proprioception and pain I11 http://www.slideshare.net/CsillaEgri/presentations • Amplitude of receptor potential is transtucted into the frequency of AP Intensity coding Somatosensitivity, viscerosensititvity, proprioception and pain I12 • In the other words: an increased intensity is associated with increase in frequency of AP • A high-intensity stimulus may also activate more receptors http://neuronresearch.net/neuron/files/neuralcode.htm Intensity coding Somatosensitivity, viscerosensititvity, proprioception and pain I13 http://slideplayer.cz/slide/3217923/ Amplitudeofreceptorpotential Actionpotentialfrequency Stimulus intensity Stimulus intensity • Relation between receptor and action potential is logarithmic Qualitative information Somatosensitivity, viscerosensititvity, proprioception and pain I14 http://www.slideshare.net/drpsdeb/presentations • The law of specific nerve energies: The nature of perception is defined by the pathway over which the sensory information is carried • Labeled line coding define the information about quality Qualitative information Somatosensitivity, viscerosensititvity, proprioception and pain I15 • Labeled line coding • Receptive field • Nerve stimulation mimics receptor stimulation http://www.slideshare.net/drpsdeb/presentations Receptive fields Somatosensitivity, viscerosensititvity, proprioception and pain I16 • Various size and overaly • Small receptive field – high resolution • Spatial resolving power increased by lateral inhibition http://www.slideshare.net/drpsdeb/presentations Lateral inhibition Somatosensitivity, viscerosensititvity, proprioception and pain I17 http://www.slideshare.net/drpsdeb/presentations Receptor adaptation Somatosensitivity, viscerosensititvity, proprioception and pain I18 • The decline of receptor responses in spite of stimulus presence • Tonic receptors – slow adaptation – presence of stimulus, position • Phasic receptors – rapid adaptation – change of stimulus http://www.slideshare.net/CsillaEgri/presentations Receptors Somatosensitivity, viscerosensititvity, proprioception and pain I19 • Simple • Complex • General – Superficial – somatosensors – Deep – viscerosensors – Muscles, tendons, joints – proprioceptors • Special – Part of sensory organs Receptors Somatosensitivity, viscerosensititvity, proprioception and pain I20 • Simple • Complex • General – Superficial – somatosensors – Deep – viscerosensors – Muscles, tendons, joints – proprioceptors • Special – Part of sensory organs Receptors Somatosensitivity, viscerosensititvity, proprioception and pain I21 http://www.slideshare.net/CsillaEgri/presentations • Simple • Complex • General – Superficial – somatosensors – Deep – viscerosensors – Muscles, tendons, joints – proprioceptors • Special – Part of sensory organs Somato/viscero/ proprio Somatosensitivity, viscerosensititvity, proprioception and pain I22 • Somatosensitivity – Pain – Temperature – Touch • Viscerosensitivity – Pain • Proprioception – Position – Movement http://www.slideshare.net/CsillaEgri/presentations Somato/viscero/ proprio Somatosensitivity, viscerosensititvity, proprioception and pain I23 • Somatosensitivity – Pain – Temperature – Touch • Viscerosensitivity – Pain • Proprioception – Position – Movement http://www.slideshare.net/CsillaEgri/presentations Evolutionary point of view Somatosensitivity, viscerosensititvity, proprioception and pain I24 http://www.slideshare.net/CsillaEgri/presentations • The signals indicating potential damage are the most important and the corresponding systems evolved early – Pain – Temperature • The touch signals have adaptive value and evolved later • The structure of the receptor, nerve fibers and pathways reflects the evolution Evolutionary point of view Somatosensitivity, viscerosensititvity, proprioception and pain I25 http://www.slideshare.net/CsillaEgri/presentations • The signals indicating potential damage are the most important and the corresponding systems evolved early – Pain – Temperature • The touch signals have adaptive value and evolved later • The structure of the receptor, nerve fibers and pathways reflects the evolution Evolutionary point of view Somatosensitivity, viscerosensititvity, proprioception and pain I26 http://www.slideshare.net/CsillaEgri/presentations • The signals indicating potential damage are the most important and the corresponding systems evolved early – Pain – Temperature • The touch signals have adaptive value and evolved later • The structure of the receptor, nerve fibers and pathways reflects the evolution Evolutionary point of view Somatosensitivity, viscerosensititvity, proprioception and pain I27 http://www.slideshare.net/CsillaEgri/presentations • The signals indicating potential damage are the most important and the corresponding systems evolved early – Pain – Temperature • The touch signals have adaptive value and evolved later • The structure of the receptor, nerve fibers and pathways reflects the evolution Free nerve endindgs Somatosensitivity, viscerosensititvity, proprioception and pain I28 http://www.slideshare.net/CsillaEgri/presentations • Non-specialized nerve endings • Polymodal – Nociception – Termoreception – Mechanoreception • A delta fibres • C fibres Nerve fibres Somatosensitivity, viscerosensititvity, proprioception and pain I29 http://www.slideshare.net/CsillaEgri/presentations Nociceptors • Free nerve endings responding to high-intensiti stimuli • Stimulus – Mechanical ✓High pressure ✓Sharp object – Thermal ✓Above aprox. 45°C ✓Low treshold – variable – Chemical ✓pH ✓Mediators of inflammation and so on Somatosensitivity, viscerosensititvity, proprioception and pain I30 Thermoreceptors Somatosensitivity, viscerosensititvity, proprioception and pain I31 http://www.slideshare.net/CsillaEgri/presentations • Free nerve endings receptive to thermal stimuli • TRP (transient receptor potential) channels • Polymodal recetor (chemoreception, thermoreception) • Present also in many cells (including neurons, keratinocytes, mechanoreceptros) Thermoreceptors Somatosensitivity, viscerosensititvity, proprioception and pain I32 • Perceived temperature is determined by relative activity of cold and warm receptors http://www.slideshare.net/CsillaEgri/presentations Thermoreceptors Somatosensitivity, viscerosensititvity, proprioception and pain I33 • Mostly phasic response http://www.slideshare.net/CsillaEgri/presentations The receptors of the skin Somatosensitivity, viscerosensititvity, proprioception and pain I34 • Simple versus complex (rapid vibration) (slow vibration, texture) (rapid vibration) (deep pressure) (movement of hairs) (sustained touch, pressure) http://www.slideshare.net/CsillaEgri/presentations The receptors of the skin Somatosensitivity, viscerosensititvity, proprioception and pain I35 http://www.slideshare.net/CsillaEgri/presentations The receptors of the skin Somatosensitivity, viscerosensititvity, proprioception and pain I36 http://neuroscience.uth.tmc.edu/s2/chapter02.html 72. Receptors, receptor potential vs. action potential, receptive field Somatosensitivity, viscerosensititvity, proprioception and pain I37 ✓ Receptor definition (energy converter) ✓ Receptor potential vs. Action potential • RP – analogue (amplitude), AP – digital (frequency) • RP – various ionic mechansims, AP - Na-K based ✓ Basic attributes of stimulus • Modality, localization, intensity, duration • The law of specific nerve energies (labeled line coding) ✓ Receptive field • Definition • Examples of large and small receptive fields, association with resolution • Lateral inhibition • Receptor adaptation (tonic and phasic response) ✓ Various classifications of receptors • Brief overview of the skin receptors