Obecná fyziologie smyslů ■ Přes receptory vstupují informace do NS ■ Smysly jsou branami do vědomí. ■ Jak vedou k subjektivní zkušenosti? gickými pochody? Otcové lili Ernst Weber 1795-1878 1801-1887 Hermann Helmholtz (1858- 1871) Transformace Transdukce Receptorová buňka Akční potenciál _ Generátorový potenciál Elektrotonické sirem *r Receptorový potenciál i aA Modality - formy energie: chemická, teplotní, mechanická, Tabic 10.1 Main types of sensory modalities Sensory modality Form of energy Receptor organ Receptor cell 1 Chemical common chemical arterial oxygen toxins (vomiting) osmotic pressure glucose pH (cerebrospinal fluid) molecules O2 tension molecules osmotic pressure glucose ions various carotid body medulla hypothalamus hypothalamus medulla free nerve endings cells and nerve endings chemoreceptor cells osmoreceptors glucoreceptors ventricle cells Taste ions and molecules tongue and pharynx taste bud cells Smell molecules nose olfactory receptors Somatosensory touch pressure heat and cold pain mechanical mechanical temperature various skin skin and deep tissue skin, hypothalamus skin and various organs nerve terminals encapsulated nerve endings nerve terminals and central neurons nerve terminals Muscle vascular pressure muscle stretch muscle tension joint position mechanical mechanical mechanical mechanical blood vessels muscle spindle tendon organs joint capsule and ligaments nerve terminals nerve terminals nerve terminals nerve terminals Balance linear acceleration (gravity) angular acceleration mechanical mechanical vestibular organ vestibular organ hair cells hair cells Hearing mechanical inner ear (cochlea) hair cells Vision electromagnetic (photons) eye (retina) photoreceptors Modified from Ganong (1985) Vstup určuje Povahu (kvalitu) vjemu- Labeled lines 3 úrovně organizace sensorických systémů B) Sensorické obvody a dráhy C) Sensorická percepce 3 úrovně organizace sensorických systémů Sensorická membrána a) mikrovili- mikroklky (vláskové buňky, vomeronasální chemorecepce, fotorecepce členovců) b) cilie - brvy, řasinky (čich v nosní sl., fotorecepce obratlovci) Mikrovily, mi kro klky Mikrofilamenta vláskové buňky, čich, vom., foto. členov. Rhabdomere Actin filamenfe Organization of sensory membráně of a photoreceptor in the fruit fty Drvw}phila |A) AtiiilDiiiy ui li Drutuplňtit pluitortteptor. The sensury membrant? fořin^i ,i stmi/tun', CiillitJ ji rhftl)i]iHiu»nj, loinpom'ii of 50,000 miťiwilli. [^) Thť mern-brane of thr mirmvilhis is hij*hly or^řinizprl by íi Sfflffolding protein ťflllert ] iST AI > {C), ivhich hinds ro pmfpins in Hip ť-ytnsnl íind pLds-tii^ membráně-11F -C" índ 1'fCC proteins ,irr sh»ivn íik if cytnsíilif but arp !ifcf*[y tn he kvist periphwally assodatetl with rhe prisma mrmbrřinp. Ahhrpviahnns: líh", aerivated form of the photopifprient rhiidopnin; Cl Ji; gufinnsine diphnsphah?; QatA, ta I modul in; CIT, giianosiru.1 triphos-phflre; PLC pJiospholLjMsc C; \J\\\. phospkiüdylinosilot 4,5-b.ibphosphaLo; 11% inusí-lo I 1,'1,5-triphosphLitc; DAC, diacyl^lyiicrol; NINAC. a form of my oslu; PKC, protein Kinase C; LU, endoplasmic reliculutn; SMC. submkroťilLqrdsicrnac. NÍNAC Cilie (brvy, řasinky) Mikrotubuly Figure 2.4 Formation of disks of a rod photoreceptor Disks are intiated at the base of the rod outer segment adjacent to a rilaim. (After Steinberg, 19&G,) cilie (čich v nosní sliznici, foto receptory obratlovců) Cilia jsou produkována z bazálních tělísek z centriol, která jsou v dělících se buňkách nezbytná pro organizaci a separaci chromozómů. U tyčinek se clium organizuje a dává vznik vychlípeninám membrány. U tyčinek pak fúzuje* membrána a měchýřky se odštípnou a tvoří vesikuly v cytoplasmě. U čípků není membránová fúze úplná, takže disky se neuzavřou. Pigmentová i vrstva Membránové disky Tyčinky Čípky Mitochondrie Jádro Axony zrakového nervu Horizontální buňky Bipolární buňky marinní buňky Gangliové buňky Úloha cytoskeletu v signálních drahách recepčních buněk Difúzni model signálového přenosu x Signalplex (transducizóm), scaffolding proteins; Multimolekulární signalizační komplex Úloha cytoskeletu v signálních drahách recepčních buněk Velká adaptabilita zraku Drosophily Translokace recepčního komplexu po aktinu podle množství dopadajícího světla. Obnova smyslové membrány Figure 2.7 Renewal of sensory membrane in a vertebrate photoreceptor Renewal of membrane in the outer segment of rod photoreceptor. Black dots indicate labeled amino acid, first incorporated into protein in the inner segment, then transported to the outer segment as components of the disk (largely as rhodopsin). Synthesis of new disks pushes label upward until, after 10-14 days, it is shed by the outer segment and phagocytosed by the cells of an adjacent cell layer, called the retinal pigment epithelium. (After Young, 1976.) Externí specializace Ochrana, podpora, účast na recepci (A) (B) i_i .0.05 mm Figure 2.8 Taste receptors of the housefly (A) Chemosensory bristles (hairs) on the tarsus of the housefly. Letters indicate different anatomical classes of hairs (type a, type b, etc; see discussion in Chapter 8). (B) Structure of a chemosensory bristle. In addition to two to four chemoreceptors, the bristle also contains a single mechanoreceptor. Trichogen and tor-mogen cells are accessory cells that secrete the hair and bristle socket. Dense object (statolith) Sensorv hairs Sensory neurons Dendrites Mec ha n o recep tor Cuticle Tormogen Trichogen Chemoreceptors M echa norecep to r cell body J^>-Neurilernma Axons í y xr Kódování signálu Receptorová buňka 7 Akční potenciál Generátorový /potenciál - JL_. Elektrotonické s— šíření ^- Receptorový potencia^ Stimulus Input 1 Sensory signals Integration Conduction Output (transmitter release) Graded receptor potent Action potential Ia: I Receptor potential Ml j Action Action potential | potential Input Graded synaptic potential 2 Motor signals Integration Conduction Output (transmitter release) Action ^potential Receptor potential Action potential / Action potential Input Graded synaptic potential 3 Muscle signals Integration Conduction Output (behavior) Action Action /potential ^potential Receptor potential Muscle spindle Sensory neuron Kódování signálu Sekundární receptor Stimulus Chemically gated channels Na"" Diffusion of Chemical messenger Afferent neuron fiber Na+ Receptor (separate cell} Primární receptor Voltage-gated channels Afferent neuron fiber Receptor (modified ending of afferent neuron) Tabic tO.l Main types of sensory modalities Sensory modality Form of energy Receptor organ Receptor cell Chemical common chemical arterial oxygen toxins (vomiting) osmotic pressure glucose pH (cerebrospinal fluid) Taste Smell Somatosensory touch pressure heat and cold pain Muscle vascular pressure muscle stretch muscle tension joint position Balance linear acceleration (gravity) angular acceleration Hearing Vision molecules O2 tension molecules. osmotic pressure glucose ions ions and molecules molecules mechanical mechanical temperature various mechanical mechanical mechanical mechanical mechanical mechanical mechanical electromagnetic (photons) various carotid body medulla hypothalamus hypothalamus medulla tongue and pharynx nose skin skin and deep tissue skin, hypothalamus skin and various organs blood vessels muscle spindle tendon organs joint capsule and ligaments vestibular organ vestibular organ inner ear (cochlea) eye (retina) free nerve endings cells and nerve endings chemoreceptor cells osmoreceptors glu co receptors ventricle cells taste bud cells olfactory receptors nerve terminals encapsulated nerve endings nerve terminals and central neurons nerve terminals nerve terminals nerve terminals nerve terminals nerve terminals hair cells hair cells hair cells photoreceptors Modified from Ganong (1985) Kódování signálu - překódování intenzity do frekvence AP j—(>)-, / ! 1 < * / / *T* - * if _\ % f) / / ml * ^/ // » i RECEPTOR CELLS llllllllllllllllll ODOR A MITRAL CELLS 1 1 III Mi (High Concentration)1 1 1 i 1 II ODOR A ——— (Low Concentration) " 1 1 II 1 1 1 1! II 11 I I I ODOR 8 ODOR C .III, I I I --1 I I I I I M I Fig. 11.11 Extracellular single-unit recordings of responses to odors of receptor cells (left) and mitral cells (right) in the salamander, showing different types of responses and different temporal patterns of activity. (After Kauer, 1974, and Getchell and Shepherd. 1978) Spontánní aktivita a centrifugální řízení Receptor potential ■jr.. Hype rpolari sat ion DepoEarisation J i m r.............riiiiJiiiiniiiintiiiHJi i i i i i L i i i J I Resting discharge Increased Impulse frequency Decreased impulse frequency EXCITATION INHIBITION Table 10.3 Common operations in sensory transduction Transduction operations Operations in single sensory cells Operations in cell populations Detection Amplification Encoding/ discrimination Adaptation and termination Sensory channel gating Electrical response I Transmission to brain Peri receptor mechanisms: filters: carriers: tuning; inactivation Sensitivity Rapidity Positive feedback Active processes Signal/noise enhancement Intensity coding Quality coding Temporal differentiation Desensitization Negative feedback Temporal discrimination Repetitive responses Open or close conductance gating Depolarization or hyperpolarization Electrotonic spread Active properties Synaptic output or impulse discharges Peri receptor mechanisms: filters; carriers; tuning; inactivation Different thresholds Positive feedback. Signal/noise enhancement Different dynamic ranges Quality independent of intensity Center—surround antagonisms Opponent mechanisms Construction of maps Temporal discrimination Spatial patterns: maps and image formation Temporal patterns: directional selectivity, etc. From Shepherd (1991b) Jednoduchá receptorová buňka (primární receptor) Inervovaná receptorová buňka (sekundární receptor) Místa vzniku akčního potenciálu a speciální konstrukce synapsí (ribbon u sluchu) Fig. 10.1 Different types of sensory receptor cells in vertebrates. Small arrows indicate sites where sensory stimuli act. Stippling indicates sites for transduction of the sensory stimuli, and also for synaptic transmission; both of these sites mediate graded signal transmission. Heavy arrows indicate sites of impulse initiation. (Adapted from Bodtan, 1967} (A) Sensory stimulus Figure 2-1 Mechanisms of sensory transduction (A) Ionotropic transduction. The stimulus directly gates an ion channel that is part of the receptor molecule. (B) Metabotropic transduction. The receptor is not itself a channel but activates a heterotrimeric G protein that initiates a transduction cascade. (B) Sensory stimulus Odorant Tight Na+ Ca2H Effector molecule Receptor G protein GTP GTP ^ Second messenger Ionotropní - přímá stimulace kanálu Metabotropní - stejně jako hormony, transmitery... Receptor ne vždy nutný - slano, MGP Table 10.2 Steps in sensory transduction Taste Transduction step Vision Olfaction Energy Photons I Membrane receptor 7TD family: rhodopsin I G protein Transducin G-protein target Phosphodiesterase Second messenger cGMP Protein kinase Membrane channel Cationic; inward i Sensory response Adaptation mechanism Cell body output Synapses Close channel i Ca~+; phosphorylation?; arrestin 1 Molecules 1 7TD family: olfactory 1 1 Adenylate cyclase HI; phospholipase C 1 cAMP; IP, Cationic; inward Anionic; inward 1 Open channel I Ca2 + ; protein kinases ? 1 Impulses Sweet/bitter amino adds Salt/sour Molecules i 7TD family: gustatory I 'gust 1 AC; PLC I cAMP; IP, I Protein kinase Á? 1 Close channel 1 ? i Synapses Na + , H' Na4; K + Open; close I ? Synapses 7 I'D family: 7 transmembrane domain receptor family. From Shepherd (1991b) Mechanorccepti on (hair cells) Displacement Cationic; inward Open channel 1 Myosin/actin motor; Ca~f ? i Synapses Weber-Fechnerův psychofyzický zákon S = a log I/Iq + b Weber gradually increased the weight that a blindfolded man was holding and asked him to respond when he first felt the increase emu Úroveň saturace ntenzita vj lín / logyS"*^ X\x\ >S Intenzita podnětu Obr. 4.15. Intenzita vjemu roste s intenzitou podnětu logaritmicky - ne lineárně. Tento kompromis mezi rozlišovací schopností a saturační m prahem (nasycením) receptoru umožňuje zachovat odstupňovanou reakci na velmi široký rozsah intenzit současně s velkou citlivostí pro slabé podněty. Neplatí ale pro všechny modality. "is this sound twice as strong as that sound?" Stevens found that such results from different sensory modalities varied too much in "steepness" to be fitted by the Webner-Fechner law. Instead he introduced a formula with one more parameter, and therefore more flexible: R = k (S-S0)alfa Exponent závisí na typu stimulu Pressure 10 10' 10J 10" 10a 10° 10' S-Sjj (relative units) 10 20 30 40 50 60 70 80 Stimulus magnitude (arbitrary units) 90 100 100 r 2 3 B 10 2030 50 100 200 50010OC Stimulus magnitude (arbitrary units log scale) B Figure 3.2 Psychophysical correlations, (a) When subjective magnitude is graphed against stimulus magnitude on linear coordinates the lines are frequently curved upwards or downwards, (b) When graphed against log-log coordinates straight lines are obtained whose gradients depend on the value of the exponent, 'ri. From Stevens, 1961 Pain has a high value of a, reflected in a steep curve. In other words, once a stimulus is strong enough to elicit pain, the pain rapidly becomes stronger as the stimulus becomes stronger. The other modalities shown have successively lower a values, which means that they can cover much wider ranges of stimulus intensity. Sensorická adaptace Diferenční receptor i Proporcionální receptor >a> ■o o o. Receptor hi air follicles Meissner Pacinian Merkel cell- Rufnnl C-fibre LTM Mechano-notfceptor subtype corpuscle corpuscle neurite complex corpuscle Poly modal nociceptor Skin L i c j 111 br li si i Dyna niic Vibration I ntf e m la i ion Stretch Touch Inj u lious forces Adaptace: inaktivace kanálů, často pod vlivem Ca, odstředivé tlumení z CNS Vliv přídatných struktur na adaptaci Paciniho tělíska Smyslový práh Zesílení, šum Časová a prostorová sumace sníží práh, ale zhorší rozlišení. Psychometrická křivka Tri res hold Stimulus intensity Figure 3.1 Psychometric curve. The threshold is defined as the intensity when half the responses are correct. The position of the curve on the ordinate is arbitrary. It will shift to the right or left according to circumstances TRP - 1969; Transient Receptor Potential - Přechodný receptorový potenciál, místo trvalé odpovědi na trvalé světlo TRP kanály kromě fotorecepce Dros. řídí mechanorecepci háďátka, octomilky, myši, člověka. Byly popsány v receptorech bolesti a teploty. U myši TRP zprostředkují vnímání některých chutí. mTHPCa (huitum TRPC2 ■i i-.L'l..yj-j(T:.- ■ Classical (short) TRPC UNIVERZÁLNI role ve smyslové transdukci Více než 50 TRP kanálů u kvasinek, hlístů, hmyzu, ryb a savců. 3 úrovně organizace sensorických systémů A) Receptory C) Sensorická percepce Ještě před vznikem digitálního zápisu se informace na periferii zpracovává. Konvergence, receptivní pole, zpětná vazba, syntéza, centrifugální vedení Receptivní pole - různé velikosti Receptivní pole - různé velikosti Velikost se může dynamicky měnit-sítnice ttícepíoc Hair follicle* tubcypo Skin |.H]lg| twUlh Stimulus Meissner H' 1111111 Dyn milic drítMiiiiiEiori Pacinian Ccrpufclc Vlurotkm MírkřlcííL- Rufflnl rViuritů complex tor pustla Inclrl ll.id.lil lk-plJl Slrclctt C-fibn?UM Tourb Mcchano-noclccplor | I1;-.--! iinnl.l1......... Inunnmfwc« function] nnwpíniil T)H|n rnoKrxi: viorirory CUOlImp ErtTtilP *)tm Mrp(cJi; llroyinr rntnofl;jmn in|iu^ di'N'f druj clipping Irjniunilli-il liy iJiMiiniinji[K>r>: iini-r[i[>rM>ridjj>'<:l vk i.i! uilri.ii Imn p.mi object* body com net wiwn f\)\.\i ^:;:r;n;ii t: f I .ir,n lni i !>l jiHir» j. i:. M 11 [wtdfrof pri mu ry «• so ry neuron* CáJl Hi^hcT-iirdcr iiilcrnc-nriinx * Ei. ľ i la LuiS i-yiupiĽ -| III hihi n iß- -.yrwf^í b NEUROBIOLOGY Gary G. Matthews DiT'.vli-.iiĽilk Topografie drah a polí - Sensorické mapy - somatotopie - retinotopie . - tonotopie - chemotopie Sensorické mapy - somatotopie - retinotopie - tonotopie - chemotopie Reprezentace odpovídajících si plošných, ale i neprostorových vlastností. Rychlost, směr, vůně responses reflect odor ants' structural properties (chain length, residues, polarity etc.): odor map carbon chain langth A ^jL CP -CP CI Ä Ä £k *k & .« - ■ 1 c"' Cytoskeleton Figure 1 General features of mechanosensory transduction, A transduction channel is anchored by intracellular and extracellular anchors to the cytoskeleton and to an extracellular structure to which forces are applied. The transduction channel responds to tension in the system, which is increased by net displacements between intracellular and extracellular structures. Inaktivovatelny CLosed Open Closed and adapted Inactivated jit i n.j-1 n a^t11 ■ Gating spring Inactivation particle Relaxing element Figure 3 | Mechanisms of mechanotransducer current desensitization. Desensitization of mechanosensitive cu rre nts m an if ests as adeclinein responsetosustain ed a p p I icati on of t he mec ha n ical sti m u lu s. The d i fferent desensitization rates of m ec han ot ra n sd u cer cu rre nts relate to thei r fu n ct ion s as sen sors of p hasic a nd ton ic sti m u li, a n d cont r ibute to the ext ra ct i on of b i olog ica lly important inFormation f rom the stim u lus. a | A series of m ech a n ica 1 sti m u li applied in 0.7-pm increments in a rat dorsal root ganglion neuron elicits a family of rapidly adapting mechanosensitive currents, b | A conditioning stimulus of increasing duration causes desensitization, manifested as a decrease in the current response to subsequently delivered test steps. C | Current—stimulus (J-X) relationships derived from (b) at different times after the onset of the conditioning stimulus illustrate the effect of desensitization. In particular, the conditioning stimulus shifts the activation curve right ward (adaptation) and reduces its amplitude relative to the control relationship (inactivation). d | A cartoon representation of the main states of mechanosensitive channels in sensory neurons. M ech an ica I forces are conveyed to the pore-forming structure through an elastic element or gating spring, which can be a cytoplasmic domain bound to phospholipidsand/or cytoskeleta I elements oran associated protein. When the gating spri ng i s stretc hed,channeldo ma in s a re pu lied a part, favouringtheopen state. As force i s ma intained,thechanneleither inactivates, possibly via a ball-and-chain mechanism, or adapts. The inactivating ball could be either a cytoskeletal element or part of thechannel protein. During adaptation, thestiffness of the gating spring remains constant but the channel reverts to a closed conformation.cT, conditioning time; I , maximum current. Figure is modified, with permission, from REE 51 ©(2010) Society for Neuroseience. f Box 11 Experimental strategies to probe mechanotransduction a Cell-based assays Stretch of a patch membrane Hypotonic cell swelling ftt Motor-driven positive pressure Membrane stretch using a magnet 1—Membrane protein b Whole-cell mecha no-clam p The development of various techniques for studying mechanotransduction has opened up new pathways for the investigation of molecular mechanisms of mechanosensation. These techniques can be used to bridge the gap between the properties of mechanotransducer currents in vitro and the characteristics of mechanoreceptors in vivo. Cell-based assays Several types of mechanical challenges can be used to activate mechanosensitive channels (see the figure, part a). These strategies are based on membrane deformation, yet each has the potential to recruit different populations of mechanosensitive channels. Motor-driven pressure. Focal deformation of the plasma membrane uses an electrically driven mechanical probe. This technique can be applied to cell bodies and neurites of sensory neurons in vitro43-48. Ceil stretch. Two methods are commonly used — surface elongation of a flexible silicone elastomer substrate on which cells have been seeded57 and application of positive or negative pressures to a patch membrane through a patch pipette36-138-159. A recently developed, related technique consists of stimulating neurites of cultured dorsal root ganglion (DRG) neurons through indentation of an elastomeric substrate adjacent to the neurite with a mechanical probe160. 8.5 um 200 pA 100 ms Hij id sJipuj-srjes.s. Shrsir stress can bn grinemrod hy changing rht; perfusion flow and/or the viscosity ot the perfusion solution. DRG neurons are sensil ive to fluid-flow changes*'. Gene ioj's and cup formers. Anionic and ne Litrů I amphipathlc compounds, sucli as free fatty etc ids. trinitrophcnol and Lysolecilhiu. preleieutially iusei I in I fie (ml pi leaflel »1 I he membrane anrl induce I he cienal ion oi ihe plasma membrane. Conversely, positively charged amp hi path ic eom pounds, such as chlorpromazincand tetracaine, insert in the inner leaflet of 11 le bilayer din I cla use the cell 1» form inp shapes. Such ampf lipathic molecules have been shown In reyulale the activities of the MslL ion channel"1 and of the two-poi e domain K* channel TRCKl and TRAAKlJB-l1tz. Osmotic challenges. Hypotonic conditions Induce r.ell swelling, whereas hypertoniclry causes cell shrinkage. I hi is, owing t o i f e Toi 11 ial ion of cell morpi ioIoejy a r id I ipid I > i layer t en si* >i i, osn lot ic var iat ions ar e 1:01 isidered hy some i eseai cl lers as a type oí mechanical slinu rial ion11. However, note lhal osmotic: si less does uol creale uniform tension in lliecell membrane and causes cytusulic alterations. iiiLludinq intiacelluEar calcium elevation and exchange of osinolyles that complicate data interpretation'1*. Mtiijiietic pm Ileitis. Tlris 1 ecf iriigue uses magnet ir: pa\\ ides lo apply forces I o cells1*3, Magnel ic pai tic:les can be c:oaled with specific llqands. Including adhesion molecules and antibodies, which enable them to bind to receptors on the cell si ii face. An a pplied ruaguel It: Field pi jlls 11 le pai 111: les so I \ ml t hey (lei i ve i uanoscale Forces at the level of I he liqand-receptor bond. Whole-cell meehano-clamp Mechanical stimulation of DRG neurons using an electrically driven mechanical probe can be achieved during patch clamping. I his technique involves the attachment at a glass microptpcttc to the surface of the cell membrane. It permits high resolution recording of single or multiple Ion channel currents flowing through the membrane.The mlerophotographs in part b of the figure show patch clamping ot DRG neurons with small (upper panci) and large (lower panel) cell body diameters. Mechauoseusit ive mji renls (lowei I races) activate gradually as a function of the stimulus sti euglh (upper tr.ic.es). I h e bl i re t race highlights tlw ci j rrr: nt ti vn k ed by the- ii, 5 u m stim i ill js. Propriorecepce-somaticky smysl S exoskeletem - Hmyz Kloubni spojeni a proprioreceptory ngure 6 urosopnita Drisne-recepior moaei. a, Lateral view of D. /ne/a/imjaster showing the hundreds of bristles that cover the fly's cuticle. The expanded view of a single bristle indicates the locations of the stereotypical set of cells and structures associated with each mechanosensory organ. Movement of the bristle towards the cuticle of the fly (arrow) displaces the dendrite and elicits an excitatory response in the mechanosensory neuron, b, Transmission electron micrograph of an insect mechanosensory bristle showing the insertion of the dendrite at the base of the bristle. The bristle contacts the dendrite (arrowhead) so that movement of the shaft of the bristle will be detected by the neuron, c, Proposed molecular model of transduction for ciliated insect mechanoreceptors, with the locations of NompC and NompA indicated. Figure 6.3 (a) The figure shows the brushwork of sensilla at the articulation of the second leg of the cockroach, Periptaneta americana. The thick cuticle of the pleuron (pt) thins to a delicate articular membrane and then thickens again to form the cuticle surrounding the coxa (cx). the first segment of the leg. The brush of sensilia forms a hairplate (hp). From Pringle, 1938 Endolyrnph Neuron Extracellular anchor (NompA) / -n i u—fc=rtm= =i-tf~i—M-j=non= Non-adapting transduction channel 1"! Intracellular link— Extracellular link § Adapting transduction channel (NompC) Adaptation machinery Aktivní zvířata potřebují informace o poloze těla a končetin S exoskeletem odlišně od endoskeletu (ih™L~»^P^, mulCles 1 and 2 SN1 - slow adapting sensory neuron; SN = fast adapting sensory neuron; S1, S2 = sensor, S£iv; \ m m0t0r>,f,bre,S t0 ,RM1: Mo2 - fhick motor f*ra to RM2: J = inhibitory fibre. From Handioofr \ ^šlachové \ tělísko Is' kosterní svat — a-motoneuron & afetentni vlákna la o II —\— y-motoneurony onulospiróini zakončeni f- vlákno s jaderným vakem - vlákno s řetézovité uspořádanými jádry svalové vřeténko extrcfyzálni' vlákna svalu t— B. Funkce svalového vřeténka 1 výchozí délka svalu receptor- extra fuzáin í vlákna svalu- svalové vřeténko 2 podráždění vřeténka „nechtěným" protažením svalu <-> reflexní kontrakce pracujícího svalu pro opětné nastavení výchozí délky svalu 3 supraspinální aktivace svalu volní změny délky svalu s preventivním nastavením (zprostředkované y-vlákny) a) žádané délky (cc-y-koaktivace} b) vyšší citlivosti senzoru {Jus i motor-set") supraspinální centra Taktilni kožní receptory - smysl pro dotek a hmat, teplotu a bolest Tlak, dotyk, vibrace. Různá adaptace receptoru i— A. Kožní senzory - neochlupená kůže zrohovatělákůže oqlhlupená kůže pokožka podkoíf 5 vlasový folikul 1 Meissnerovo tělisko (RA-senzor) E=j 2 Merkelůvdisk (SA l-senzor) 3 Ruffíniho tělísko (SA il-senzor) nervová vlákna 4 Vater-Púciniho tělísko ■— B. Reakce kožních senzorů na tlak (1), dotyk (2) a vibrace (3) - lOg 20g «9 podnět: tlak závaží lOg 10g 19 AA A/W rychlost změny tlak j změna rychlosti mm odpověď: akční potenciály (impulzy) 100 10 1 10 100 intenzita podnětu (g) 0,1 1 10 rychlost směny tlaku (mm/s) 20 40 80 200 400 frekvence vibrací (Hz) (podle Zimmermanna a Schmidta) C. Reakce termo receptoru 12 25 30 35 40 teplota kůže CC) D. PD-propriorecepce: reakce na rychlost a úhel ohýbání kloubu (text viz následující str.) ohýbání 2 úhel ŕ rychlé střední pomalé velký střední malý stejná rychlost ohýbání D-senzor stejné konečné postavení P-senzor různé konečné postavení 0 5 10 15 (podle Boyda a Ftobertse) Čas (s) 10 15 Čas (s) ^228 Receptory on-line http://www.sinauerxom/wolfe3e/chapl2/ssreceptorsF.htm Dennis I piik Mefhnmorwepicrs Toucly vjtiniüwi l' i i -1 ■: - ■ ■ - - -MydinnliĽd iixchi MetwnťrtdľpiiKľlr Touvh; vjhruljwi Etapu] JuhipHiiliwi Mydiruicd mein R u 111 n t ĽoijiiMvk Slmv ilda|H*lľ»ň Mwfcŕl diak i......■■. ■■■ -. - Slow lud^IMtlufl Mydinalsd iiíähi miŤaUklc rtíi:eploľ I Lin ■! \ii m |!...|- I i..l;i|':,H..... Mv-ľIihhľJ uicjií 'J'hrrmurrttplurK Uünci lUfiiiiytľlimjlĽiJ ujlhm] KjflJ íľ-nUllĽ] |i ľ, 1 -|:...ki: UKM ■ S':\'-fl liiniii>Ľlin.'ilLj iijlliii b NEUROBIOLOGY Gary G. Matthews Receptor H a (r folií c I e s subtype Skin Light brush stimulus Meissner corpuscle Dynamic deformation Pacinian corpuscle Merkel cell- Ruffinl n e u rite comple x corpuscle C-fibre LTM Mecha no-nociceptor Poly modal nociceptor Afferent ^ Ll response Stimulus Receptive field Perceptual Skin functions movement Skin ! i h Mi i li i. detecting slipping objects Vibratory cues i; .ll '-.i i ľu-tl pain - rĽĽĽplLTS ľC-íibcm Tü brain Dotek, vibrace, svaly Vstup dorzálními kořeny a dorzáln From uiih.ii, 'Ith"kIhhľi i ľľľ|--. id ľrtWftíiw^lc jaJ Dtirul nutí ľ;iili;Líľiji CKHTdl utlmím mi sl )upci do mozku 4 4 i"ii|'i|nii To mu-^'ta M;:Cíít iiľuj'.iii L;v;il v,Hj.]iUľ b Rh:-.™! NEUROBIOLOGY Gary G. Matthews Proprioreceptory Vstup dorzálními kořeny a spinocerebrálním traktem do mozku Tu bonin Ti* tiniin Servány ■en renin SrniiLvtr^Mljc I -Vi i i li j ■: i i fi I and Miii!-A.-|c njLupliir^ .Lnd: frh.tqi-IrjiiLiPc TůTíZjiLnrs NEUROBIOLOGY Gary G. Matthews Somatotopie Sensorické dráhy Somatotopie Vstup do talamu NEUROBIOLOGY Gary G. Matthews Somatotopie somatosensorické kůry CViH i j.I Ptiitury iU|ľU:i MiiiulĽOJiiihĽTy Ľ"i k Somatotopie somatosensorické kůry -Fantomová bolest http://sites.sinauer.com 3e/chapl3/homunculusl Vertikální členění kortexu Sloupečky somatosensorické kůry odpovídající submodalitám Plasticita somatosensorické kůry Reprezentace se mění podle používání Houslisté, slepci A B Figure 7.16 Mouse whisker barrels, (a) Head showing five rows of vibrissae. (b) Section of cortex showing 'barrels', each corrresponding to one whisker, (c) Diagram to show the organisation of the whisker barrels, (d) Diagrams to show the effect of removing whiskers, (i) Full set of whiskers, full set of barrels; (ii) one row of whiskers removed, unaffected barrels grow into territory of unused barrels; (iii) one column of whiskers removed; again unaffected barrels colonise space left by missing barrels; (iv) total removal of whiskers; loss of all barrels. A, B, and C from Woolsey & van der Loos, 1970: with permission. D from Cowan, 1979: with permission