10/28/2011 Reafference Principle Holst E. von and Mittelstaedt H. ( - PDF document

10/28/2011 Reafference Principle Holst E. von and Mittelstaedt H. ( 1950 ) Da;. Reafferenzprincip. L36. EXPECTATION GENERATORS Naturwissenschaften 37, 464 ‐ 476. October 28, 2011 C. D. Hopkins “Much of sensory processing involves the generation of expectations or predictions about sensory input, and subsequent removal of such expectations from the sensory inflow.” Bell, C (1997) Brain, Behavior, Evolution 50 (suppl.) 17-31. 2 Crayfish Escape Response Cricket Stridulation Mormyrid electric fish produce an ‘electromotor’ command, and receive 3 Electroreceptors a electrosensory response as a consequence. Knollenorgans (KO) Communication Single spike, short latency bulbar command associated n. midbrain command associated n. juxtalemniscal cells – to NELL 5 6 Meek, Grant and Bell. The Journal of Experimental Biology 202, 1291–1300 (1999) 1

10/28/2011 C. C. Bell and K. Grant XU-FRIEDMAN, M. A. & HOPKINS, C. D., 1999.- J. Exp. Biol. , 202:1311-1318. 7 8 FRIEDMAN, M.A. & HOPKINS, C.D. 1998 – J. Neurosci.18:1171-1185. Knollenorgans blank inputs by inhibition --Primary afferent (blue) EOD command terminates on nELL cell (yellow) with ipsp in nELL cell --large calyx-like synapses (electrotonic). --fibers from EOD fibers from EOD afferent command (eocd) produce spikes that command arrive at same time that EOD would be fired. --sharp inhibition IPSP blocks spike at the EOD time when EOD is expected -- removes expected XU-FRIEDMAN, M. A. & HOPKINS, C. D., 1999.- J. Exp. Biol. , 202:1311-1318. 9 10 EOD FRIEDMAN, M.A. & HOPKINS, C.D. 1998 – J. Neurosci.18:1171-1185. 3. Ampullary Receptors (=D.C. receptors) 2 Mormyromasts Ampullary (ao) Mormyromasts (morm) Respond to D.C. stimuli Active electrolocation. Passive electrolocation of prey. Burst duration code Frequency code. 11 12 2

10/28/2011 A Modifiable Efference Copy Bell, CC (1982) Recording setup: 1) mormyrid electric fish 2) curarize electric fish – silence the electric organ 3) record command signal in tail 4) stimulate artificially, using command 5) record in ampullary electrosensory area of ELL 13 14 Meek, Grant and Bell. The Journal of Experimental Biology 202, 1291–1300 (1999) Principal Cell Plasticity Principal Cell Plasticity EOD command EOD command 15 16 The negative image works for any Modifiable Negative Image in histogram form stimulus delay after the command 17 18 COMMAND COMMAND 3

10/28/2011 Electrosensory Plasticity in The negative image compensates stimulus applied anywhere on body surface Gymnotiform Fishes Apteronotus leptorhynchus Eigenmannia virescens All recording from same ELL cell; stimulus applied to A, B, C, or D 19 20 Bastian: Sensory Consequence of Propioceptors Monitor Tail Position Movement of Tail Experimental paradigm: 1) Tail movement controlled by motor. 2) Electric discharge continues and stimulates d ti l t electroreceptors. 3) Electrode near skin monitors the EOD amplitude Electrophysiological recordings from propioceptors in the EGp of Apteronotus in response to tail bending experiment. Propioceptors monitor all positions of tail bend. (increases, decreases, middle). 21 22 Electrosensory Feedback From Tail If tail is not bent during artificial Bending is Cancelled in ELL Amplitude modulation, no effect The cancellation is modifiable over time. 23 24 4

10/28/2011 Effect of Global EOD on Local Now, with removal of EOD Electrosensory Response x A) Response of basilar Now, the EOD is silenced to pyramidal cell to whole prevent global stimulation. body AM. y A) Tail is moved back and forth B) Body AM plus local AM to provide the B4) Body AM alone, local proprioceptive cue. AM off. B) Local AM causes stimulation of electroreceptors. C) After pairing, response to tail movement alone, no 25 AM 26 The Basic Architecture 27 1. Bell, C. C., Han, V. and Sawtell, N. B. (2008). Cerebellum-like structures and their implications for cerebellar function. Annu R N i 31 1 24 Anatomy Methods (continued) Identification of Mossy Fibers in Egp. 1) Previous studies by Bell (1991) recorded from cells in EGp with similar properties and found * no synaptic activity, *spikes arising directly from baseline. 2) Several fills with biocytin (3 from proprioceptive input, 2 with EODc input) 3) No neurons responded to both EODc and propioception. 4) Pairing of EODCD synaptic activity and narrow spike activity by averaging responses before Injection of biotinylated dextran into molecular layer of ELL labels: and after EODCD, narrow spikes MG cells (gabaergic cells in ELL) removed. granule cells which project via parallel fibers to MGcell dendrites. 5

10/28/2011 Many Mossy Fibers provide propioceptive sensory information from Some mossy fibers respond to EOD tail. (most common type of unit) command responds to tail bend, Putative MossyFiber cell not EODc. responding to EODc. Spike rate unchanged by EOD. No spontaneous activity. Firing rate is 20-150 Hz. most preferred Response precedes EOD. extremes. A few Has a best tail angle g intermediate occasion occasion angles l al cell 3 units showing differing Spike rate encodes tail angle had latencies of responses. shown for 3 units that prefer burst, Stereotyped rasters. contralateral bend, 3 that prefer then ipsilateral bend. long latency burst. Some proprioceptor units Summed histograms of respond to schnauzenorgan spikes per command from displacement, trunk 30 such units. displacement or fin. Active for up to 400 msec after EODc Circuitry in the ELL 33 34 Recording Plasticity in Slice Theory to Explain Negative Image Preparation Sensory input arrives from Recording intracellularly from an below and stimulates pyramidal ELL cell from mormyromast region cell to fire. of mormyrid ELL. Predictive input comes from above through parallel fibers. Stimulate parallel fibers with two Synaptic modification changes sets of electrodes in molecular strength of predictive input as a layer of ELL. consequence of simultaneous action. 35 36 6

10/28/2011 Spike timing dependent plasticity is anti-hebbian. If the broad spike occurs Other Examples of after the EPSP, the synaptic weight is decreased. If the broad spike occurs before the EPSP, it strengthens. This sculpts a negative image of the Removing Expected Inputs expected input. • Adaptation of receptors or neurons to maintained stimuli removes responses to constant stimulus. • Lateral inhibition: remove expected mean levels L t l i hibiti t d l l over space.” Both methods use simple non-plastic cellular changes (self inhibition, intra-cellular inhibition). Percentage change in excitatory postsynaptic potential (EPSP) amplitude plotted against the delay between EPSP onset and the broad spike peak during pairing. A negative delay with regard to the previous spike and a positive delay with regard to the following spike were present for each pairing. The shorter of these two delays is plotted. Filled circles, significant changes; open circles, non-significant changes (at P <0.01). 38 animation rule 7