insertion-flexible-neural-probes-using-rigid-stiffeners-attached-with

Insertion of Flexible Neural Probes Using Rigid Stiffeners Attached with Biodissolvable Adhesive

Microelectrode  arrays for neural interface devices that are made of biocompatible thin-film  polymer are expected to have extended functional lifetime ...

University of California, San Francisco

The temporal features of tactile stimuli are faithfully represented by the activity of neurons in the somatosensory cortex. However, the cellular mechanisms that enable cortical neurons to report accurate temporal information are not known. Here, we show that in the rodent barrel cortex, the temporal window for integration of thalamic inputs is under the control of thalamocortical feed-forward inhibition and can vary from 1 to 10 ms. A single thalamic fiber can trigger feed-forward inhibition and contacts both excitatory and inhibitory cortical neurons. The dynamics of feed-forward inhibition exceed those of each individual synapse in the circuit and are captured by a simple disynaptic model of the thalamocortical projection. The variations in the integration window produce changes in the temporal precision of cortical responses to whisker stimulation. Hence, feed-forward inhibitory circuits, classically known to sharpen spatial contrast of tactile inputs, also increase the temporal resolution in the somatosensory cortex.

Somatosensory integration controlled by dynamic thalamocortical feed-forward inhibition.

How the brain encodes relevant sensory stimuli in the context of active, natural sensation is not known. During active tactile sensation by rodents, whisker movement across surfaces generates complex whisker micro-motion, including discrete, transient slip-stick events, which carry information about surface properties. We simultaneously measured whisker motion and neural activity in somatosensory cortex (S1) in rats whisking across surfaces. Slip-stick motion events were prominently encoded by one or two low-probability, precisely timed spikes in S1 neurons, resulting in a probabilistically sparse ensemble code. Slips could be efficiently decoded from transient, correlated spiking (approximately 20-ms time scale) in small (approximately 100 neuron) populations. Slip responses contributed substantially to increased firing rate and transient firing synchrony on surfaces, and firing synchrony was an important cue for surface texture. Slips are thus a fundamental encoded tactile feature in natural whisker input streams and are represented by sparse, temporally precise, synchronous spiking in S1.

Sparse temporal coding of elementary tactile features during active whisker sensation.

The consolidation of memory is thought to occur via a hippocampal-neocortical dialog involving reactivation of memory patterns in the hippocampus during sharp-wave ripples. In this issue of Neuron, Nakashiba et al. demonstrate that CA3 output is required for consolidation of contextual fear memory. They also show that lack of CA3 output results in a decrease in ripple-related reactivation, providing additional evidence for a role of ripple-related reactivation in the consolidation process.

Reactivating memories for consolidation.

&#x7C7B;&#x578B; 1 &#x5927;&#x9EBB;&#x7D20; &#xFF08;CB1&#xFF09; &#x53D7;&#x4F53;&#x8C03;&#x89E3;&#x5E7F;&#x6CDB;&#x7684;&#x7A81;&#x89E6;&#x53EF;&#x5851;&#x6027;&#xFF0C;&#x4F46;&#x8FD9;&#x5982;&#x4F55;&#x6709;&#x52A9;&#x4E8E;&#x7CFB;&#x7EDF;&#x7EA7;&#x53EF;&#x5851;&#x6027;&#x548C;&#x4F53;&#x5185;&#x7684;&#x53D1;&#x5C55;&#x76EE;&#x524D;&#x8FD8;&#x4E0D;&#x6E05;&#x695A;&#x3002;&#x6211;&#x4EEC;&#x6D4B;&#x8BD5;&#x662F;&#x5426;&#x5728;&#x5927;&#x9F20;&#x4F53;&#x611F;&#x76AE;&#x8D28; CB1 &#x4FE1;&#x53F7;&#x662F;&#x53D1;&#x5C55;&#x548C;&#x53EF;&#x5851;&#x6027;&#x7684;&#x6676;&#x987B;&#x5730;&#x56FE;&#x6240;&#x5FC5;&#x9700;&#x7684;&#x3002;CB1 &#x62EE;&#x6297;&#x5242; AM251 &#x5728;&#x65E9;&#x671F;&#x7684;&#x5173;&#x952E;&#x65F6;&#x671F;&#xFF0C;&#x4E3A;&#x56FE;&#x5C42; (L) &#x4E2D;&#x65AD;&#x7684;&#x53D1;&#x5C55; 2/3 (&#x5F00;&#x59CB;&#x4EA7;&#x540E;&#x5929; [P] 12-16) &#x6676;&#x987B;&#x5904;&#x7406;&#x6620;&#x5C04;&#x53D1;&#x5C55;&#xFF0C;&#x5BFC;&#x81F4;&#x4E0D;&#x6070;&#x5F53;&#x6676;&#x987B;&#x8C03;&#x6574; L2/3 &#x5217;&#x8FB9;&#x7F18;&#x548C;&#x6A21;&#x7CCA;&#x7684;&#x56FE;&#x4E2D;&#x3002;&#x65E9;&#x671F; AM251 &#x6CBB;&#x7597;&#x4E5F;&#x59A8;&#x788D;&#x4E86; L2/3&#xFF0C;&#x5305;&#x62EC;&#x5265;&#x593A;&#x8BF1;&#x5BFC;&#x7A81;&#x89E6;&#x524A;&#x5F31;&#xFF0C;&#x524A;&#x5F31;&#x4E86;&#x88AB;&#x5265;&#x593A;&#x4E86;&#x6676;&#x987B;&#x54CD;&#x5E94;&#x7684;&#x53EF;&#x5851;&#x6027;&#x3002;CB1 &#x5C01;&#x9501;&#x540E;&#x5730;&#x56FE;&#x5F00;&#x53D1;&#x6216;&#x53EF;&#x5851;&#x6027; P25 &#x4E0D;&#x4F1A;&#x4E2D;&#x65AD;&#x3002;AM251 &#x4E86;&#x611F;&#x5B98;&#x8BF1;&#x53D1;&#x8282;&#x5F8B;&#x548C;&#x6F5C;&#x529B;&#xFF0C;&#x7565;&#x53D7;&#x5F71;&#x54CD;&#x7684;&#x9886;&#x57DF;&#x552F;&#x4E00;&#x6CA1;&#x6709;&#x6025;&#x6027;&#x5F71;&#x54CD;&#x8868;&#x660E;&#x53EF;&#x5851;&#x6027;&#x7684;&#x5F71;&#x54CD;&#x5E76;&#x4E0D;&#x6B21;&#x8981;&#x7684;&#x603B;&#x6D3B;&#x52A8;&#x53D8;&#x5316;&#x3002;&#x8FD9;&#x4E9B;&#x7814;&#x7A76;&#x7ED3;&#x679C;&#x7275;&#x8FDE; CB1 &#x4F9D;&#x8D56;&#x5728;&#x7CFB;&#x7EDF;&#x7EA7;&#x5F00;&#x53D1;&#x7684;&#x53EF;&#x5851;&#x6027;&#x548C;&#x65E9;&#x671F;&#x4EA7;&#x540E;&#x53EF;&#x5851;&#x6027;&#x7684;&#x6676;&#x987B;&#x5730;&#x56FE;&#x3002;

Endocannabinoid &#x4FE1;&#x53F7;&#x662F;&#x5FC5;&#x9700;&#x7684;&#x53D1;&#x5C55;&#x548C;&#x5173;&#x952E;&#x65F6;&#x671F;&#x53EF;&#x5851;&#x6027;&#x7684;&#x6676;&#x987B;&#x5730;&#x56FE;&#x4F53;&#x611F;&#x76AE;&#x5C42;&#x3002;

Type 1 cannabinoid (CB1) receptors mediate widespread synaptic plasticity, but how this contributes to systems-level plasticity and development in vivo is unclear. We tested whether CB1 signaling is required for development and plasticity of the whisker map in rat somatosensory cortex. Treatment with the CB1 antagonist AM251 during an early critical period for layer (L) 2/3 development (beginning postnatal day [P] 12-16) disrupted whisker map development, leading to inappropriate whisker tuning in L2/3 column edges and a blurred map. Early AM251 treatment also prevented experience-dependent plasticity in L2/3, including deprivation-induced synapse weakening and weakening of deprived whisker responses. CB1 blockade after P25 did not disrupt map development or plasticity. AM251 had no acute effect on sensory-evoked spiking and only modestly affected field potentials, suggesting that plasticity effects were not secondary to gross activity changes. These findings implicate CB1-dependent plasticity in systems-level development and early postnatal plasticity of the whisker map.

Endocannabinoid signaling is required for development and critical period plasticity of the whisker map in somatosensory cortex.

Type 1 (CB1) r&Theta;cepteurs m&eacute;dient la plasticit&eacute; synaptique g&eacute;n&eacute;ralis&eacute;e, mais comment cela contribue &agrave; la plasticit&eacute; au niveau des syst&egrave;mes et d&eacute;veloppement in vivo n&#39;est pas claire. Nous avons v&eacute;rifi&eacute; si CB1 signalisation est n&eacute;cessaire pour le d&eacute;veloppement et la plasticit&eacute; de la carte de moustaches dans le cortex somatosensoriel. Traitement avec la moustache de d&eacute;veloppement de 2/3 (d&eacute;but jour apr&egrave;s la naissance [P] 12-16) perturb&eacute; CB1 antagoniste AM251 pendant une p&eacute;riode critique au d&eacute;but de la couche (L) plan de d&eacute;veloppement, menant &agrave; moustaches inappropri&eacute; tuning en L2/3 bords de colonne et une carte floue. Un traitement pr&eacute;coce AM251 a &eacute;galement emp&ecirc;ch&eacute; exp&eacute;rience d&eacute;pendant plasticit&eacute; en L2/3, y compris la fragilisation induite par la privation synapse et affaiblissement des r&eacute;ponses de moustaches d&eacute;munies. CB1 blocus apr&egrave;s P25 ne pas perturber carte d&eacute;veloppement ou plasticit&eacute;. AM251 a eu aucun effet aigu sur &eacute;voqu&eacute;e par sensorielle de fortification et des potentiels de champ modestement affect&eacute;e uniquement, sugg&eacute;rant que les effets de la plasticit&eacute; ne sont pas secondaires &agrave; brute des changements d&#39;activit&eacute;. Ces r&eacute;sultats impliquent la plasticit&eacute; d&eacute;pendante CB1 au niveau des syst&egrave;mes de d&eacute;veloppement et la plasticit&eacute; postnatale pr&eacute;coce de la carte de la moustache.

Signalisation d&#39;endocannabinoid est requise pour le d&eacute;veloppement et la plasticit&eacute; p&eacute;riode critique de la carte de moustaches dans le cortex somatosensoriel.

Typ 1-Cannabinoidrezeptoren (CB1) vermitteln weit verbreitete synaptische Plastizit&auml;t, aber es ist unklar, wie dies zur Systemebene Plastizit&auml;t und in-vivo-Entwicklung beitr&auml;gt. Wir haben getestet, ob CB1 Signalisierung in Ratte somatosensorischen Kortex f&uuml;r Entwicklung und Plastizit&auml;t der Barthaar-Karte erforderlich ist. Behandlung mit der CB1 Antagonist AM251 in einer fr&uuml;hen kritischen Periode f&uuml;r Layer (L) 2/3-Entwicklung (Beginn postnatale Tag [P] 12-16) gest&ouml;rt barthaare Landkarte Entwicklung, zu unangemessenen barthaare tuning im L2/3 Spalte Kanten und einer unscharfen Karte f&uuml;hrt. Fr&uuml;her AM251 Behandlung verhindert auch Erfahrung-abh&auml;ngigen Plastizit&auml;t in L2/3, einschlie&szlig;lich induziert durch Entbehrungen Synapse Schw&auml;chung und Schw&auml;chung der benachteiligten barthaare Antworten. CB1-Blockade nach P25 keine Karte Entwicklung oder Plastizit&auml;t st&ouml;ren. AM251 hatte keine akute Auswirkungen auf spiking sensorische hervorgerufen und nur bescheiden betroffenen Bereich M&ouml;glichkeiten, darauf hindeutet, dass die Plastizit&auml;t Wirkung nicht sekund&auml;re Aktivit&auml;t &Auml;nderungen grobe waren. Diese Erkenntnisse implizieren CB1-abh&auml;ngigen Plastizit&auml;t in der Systemebene Entwicklung und fr&uuml;he postnatale Plastizit&auml;t der barthaare Karte.

Endocannabinoid Signalisierung ist im somatosensorischen Kortex f&uuml;r Entwicklung und kritische Periode Plastizit&auml;t der Barthaar-Karte erforderlich.

I recettori dei cannabinoidi (CB1) tipo 1 mediano plasticit&agrave; sinaptica diffusa, ma non &egrave; chiaro come questo contribuisce a livello di sistemi plasticit&agrave; e lo sviluppo in vivo. Abbiamo testato se CB1 segnalazione &egrave; necessaria per lo sviluppo e la plasticit&agrave; della mappa whisker nella corteccia somatosensoriale ratto. Il trattamento con il soffio di sviluppo 2/3 (inizio postnatale giorno [P] 12-16) perturbato CB1 antagonista AM251 durante un periodo critico per strato (L) mappa sviluppo, portando a whisker inappropriato in sintonia L2/3 colonna bordi e mappa offuscata. Il trattamento precoce AM251 impedito anche plasticit&agrave; esperienza-dipendente in L2/3, tra cui privazione indotta sinapsi indebolimento e indebolimento delle risposte whisker svantaggiate. CB1 blocco dopo P25 ha fatto non disturbare lo sviluppo mappa o plasticit&agrave;. AM251 ha avuto alcun effetto acuto su sensoriale evocata chiodare e solo modestamente interessato campo potenzialit&agrave;, suggerendo che gli effetti di plasticit&agrave; non erano secondari al lordo cambi attivit&agrave;. Questi risultati implicano plasticit&agrave; CB1-dipendente a livello di sistemi di sviluppo e plasticit&agrave; postnatale precoce della mappa whisker.

Endocannabinoide segnalazione &egrave; necessaria per lo sviluppo e plasticit&agrave; periodo critico della mappa whisker nella corteccia somatosensoriale.

&#x30BF;&#x30A4;&#x30D7; 1 &#x30AB;&#x30F3;&#x30CA;&#x30D3;&#x30CE;&#x30A4;&#x30C9; &#xFF08;CB1&#xFF09; &#x53D7;&#x5BB9;&#x4F53;&#x666E;&#x53CA;&#x306E;&#x30B7;&#x30CA;&#x30D7;&#x30B9;&#x53EF;&#x5851;&#x6027;&#x3092;&#x4EF2;&#x4ECB;&#x3059;&#x308B;&#x304C;&#x3069;&#x306E;&#x3088;&#x3046;&#x306B;&#x3053;&#x306E;&#x30B7;&#x30B9;&#x30C6;&#x30E0; &#x30EC;&#x30D9;&#x30EB;&#x306E;&#x53EF;&#x5851;&#x6027;&#x3068; in vivo &#x306E;&#x767A;&#x5C55;&#x306B;&#x8CA2;&#x732E;&#x3059;&#x308B;&#x306F;&#x660E;&#x3089;&#x304B;&#x3067;&#x3059;&#x3002;&#x6211;&#x3005; &#x306F;&#x3001;CB1 &#x30B7;&#x30B0;&#x30CA;&#x30EA;&#x30F3;&#x30B0; &#x30E9;&#x30C3;&#x30C8;&#x4F53;&#x6027;&#x611F;&#x899A;&#x76AE;&#x8CEA;&#x3067;&#x306F;&#x958B;&#x767A;&#x3068;&#x30A6;&#x30A3;&#x30B9;&#x30AB; &#x30DE;&#x30C3;&#x30D7;&#x306E;&#x53EF;&#x5851;&#x6027;&#x306E;&#x305F;&#x3081;&#x306B;&#x5FC5;&#x8981;&#x304B;&#x3069;&#x3046;&#x304B;&#x30C6;&#x30B9;&#x30C8;&#x3057;&#x307E;&#x3059;&#x3002;&#x6CBB;&#x7642; CB1 &#x30EC;&#x30A4;&#x30E4;&#x30FC; &#xFF08;L&#xFF09; &#x306E;&#x91CD;&#x8981;&#x306A;&#x521D;&#x671F;&#x306E;&#x4E2D;&#x306B; AM251 &#x62EE;&#x6297;&#x85AC;&#x4E2D;&#x65AD; 2/3 &#x958B;&#x767A; (&#x5148;&#x982D;&#x751F;&#x5F8C;&#x65E5; [P] 12-16) &#x30A6;&#x30A4;&#x30B9;&#x30AB;&#x30FC;&#x3067;&#x4E0D;&#x9069;&#x5207;&#x306A;&#x30A6;&#x30A3;&#x30B9;&#x30AB; L2/3 &#x5217;&#x30A8;&#x30C3;&#x30B8;&#x3068;&#x307C;&#x3084;&#x3051;&#x30DE;&#x30C3;&#x30D7;&#x306E;&#x30C1;&#x30E5;&#x30FC;&#x30CB;&#x30F3;&#x30B0;&#x306B;&#x3064;&#x306A;&#x304C;&#x308B;&#x958B;&#x767A;&#x3092;&#x30DE;&#x30C3;&#x30D7;&#x3057;&#x307E;&#x3059;&#x3002;&#x65E9;&#x671F; AM251 &#x6CBB;&#x7642;&#x3082; L2/3 &#x5265;&#x596A;&#x4F9D;&#x5B58;&#x7684;&#x306A;&#x30B7;&#x30CA;&#x30D7;&#x30B9;&#x306E;&#x5F31;&#x4F53;&#x5316;&#x3001;&#x596A;&#x308F;&#x308C;&#x305F;&#x30A6;&#x30A4;&#x30B9;&#x30AB;&#x30FC; &#x30EC;&#x30B9;&#x30DD;&#x30F3;&#x30B9;&#x306E;&#x5F31;&#x4F53;&#x5316;&#x306A;&#x3069;&#x306E;&#x7D4C;&#x9A13;&#x4F9D;&#x5B58;&#x7684;&#x53EF;&#x5851;&#x6027;&#x3092;&#x9632;&#x6B62;&#x3057;&#x307E;&#x3057;&#x305F;&#x3002;CB1 &#x5C01;&#x9396; P25 &#x5F8C;&#x306F;&#x30DE;&#x30C3;&#x30D7;&#x306E;&#x958B;&#x767A;&#x307E;&#x305F;&#x306F;&#x53EF;&#x5851;&#x6027;&#x306B;&#x306F;&#x5F71;&#x97FF;&#x3092;&#x53CA;&#x307C;&#x3055;&#x306A;&#x3044;&#x3002;AM251 &#x6025;&#x6027;&#x52B9;&#x679C;&#x306E;&#x611F;&#x899A;&#x8A98;&#x767A;&#x30B9;&#x30D1;&#x30A4;&#x30AF; &#x30FB;&#x552F;&#x4E00;&#x306E;&#x63A7;&#x3048;&#x3081;&#x306A;&#x5F71;&#x97FF;&#x3092;&#x53D7;&#x3051;&#x308B;&#x30D5;&#x30A3;&#x30FC;&#x30EB;&#x30C9;&#x96FB;&#x4F4D;&#x6D3B;&#x52D5;&#x5909;&#x5316;&#x3092;&#x7DCF;&#x30BB;&#x30AB;&#x30F3;&#x30C0;&#x30EA;&#x3067;&#x306A;&#x304F;&#x53EF;&#x5851;&#x6027;&#x52B9;&#x679C;&#x3092;&#x793A;&#x5506;&#x304C;&#x306A;&#x304B;&#x3063;&#x305F;&#x3002;&#x3053;&#x308C;&#x3089;&#x306E;&#x8ABF;&#x67FB;&#x7D50;&#x679C; CB1 &#x4F9D;&#x5B58;&#x53EF;&#x5851;&#x6027;&#x306E;&#x30B7;&#x30B9;&#x30C6;&#x30E0; &#x30EC;&#x30D9;&#x30EB;&#x306E;&#x958B;&#x767A;&#x3068;&#x30A6;&#x30A3;&#x30B9;&#x30AB; &#x30DE;&#x30C3;&#x30D7;&#x306E;&#x521D;&#x671F;&#x751F;&#x5F8C;&#x53EF;&#x5851;&#x6027;&#x3092;&#x5DFB;&#x304D;&#x8FBC;&#x307F;&#x307E;&#x3059;&#x3002;

&#x30AB;&#x30F3;&#x30CA;&#x30D3;&#x30CE;&#x30A4;&#x30C9;&#x3092;&#x30B7;&#x30B0;&#x30CA;&#x30EA;&#x30F3;&#x30B0;&#x4F53;&#x6027;&#x611F;&#x899A;&#x76AE;&#x8CEA;&#x3067;&#x306F;&#x958B;&#x767A;&#x3068;&#x30A6;&#x30A3;&#x30B9;&#x30AB;&#x306E;&#x5730;&#x56F3;&#x306E;&#x91CD;&#x8981;&#x306A;&#x671F;&#x9593;&#x53EF;&#x5851;&#x6027;&#x306E;&#x305F;&#x3081;&#x304C;&#x5FC5;&#x8981;&#x3067;&#x3059;&#x3002;

1 &#xD615; (CB1) cannabinoid &#xC218;&#xC6A9; &#xCCB4; &#xAD11;&#xBC94;&#xC704; &#xD55C; &#xC2DC; &#xB0C5; &#xC2A4;&#xAC00; &#xC18C;&#xC131;&#xC744; &#xC911;&#xC7AC; &#xD558;&#xC9C0;&#xB9CC; &#xC5B4;&#xB5BB;&#xAC8C;&#xC774; &#xC2DC;&#xC2A4;&#xD15C; &#xC218;&#xC900; &#xC18C;&#xC131; &#xBC0F; &#xC0DD;&#xCCB4; &#xC870;&#xAC74; &#xAC1C;&#xBC1C;&#xC5D0; &#xAE30;&#xC5EC; &#xD558;&#xB294; &#xAC83;&#xC740; &#xBD84;&#xBA85; &#xD569;&#xB2C8;&#xB2E4;. &#xC6B0;&#xB9AC;&#xAC00; &#xD14C;&#xC2A4;&#xD2B8; &#xC950; somatosensory &#xD53C; &#xC9C8;&#xC5D0;&#xC11C; &#xAC1C;&#xBC1C; &#xBC0F; &#xC218;&#xC5FC; &#xC9C0;&#xB3C4;&#xC758; &#xC18C;&#xC131;&#xC740; CB1 &#xC2E0;&#xD638;. CB1 AM251 &#xB808;&#xC774;&#xC5B4; (L)&#xC5D0; &#xB300; &#xD55C; &#xCD08;&#xAE30; &#xC911;&#xC694; &#xD55C; &#xAE30;&#xAC04; &#xB3D9;&#xC548; &#xC801;&#xC5D0; &#xAC8C; 2/3 &#xAC1C;&#xBC1C; (&#xCC98;&#xC74C; &#xC0B0; &#xD6C4; &#xD558;&#xB8E8; [P] 12 &#xC6D4; 16 &#xC77C;) &#xC911;&#xB2E8; &#xC218;&#xC5FC; &#xCE58;&#xB8CC; &#xC9C0;&#xB3C4; &#xBC1C;&#xB2EC;, L2/3 &#xC5F4; &#xAC00;&#xC7A5;&#xC790;&#xB9AC;&#xC640; &#xD750;&#xB9B0;&#xB41C; &#xC9C0;&#xB3C4;&#xC5D0;&#xC11C; &#xD29C;&#xB2DD; &#xD558;&#xB294; &#xBD80;&#xC801;&#xC808; &#xD55C; &#xC218;&#xC5FC;&#xC744; &#xC120;&#xB3C4;. AM251 &#xCE58;&#xB8CC; &#xCD08;&#xAE30;&#xC5D0; L2/3, &#xBD80;&#xC871; &#xC720;&#xBC1C; &#xB0C5; &#xC57D;&#xD654; &#xB4F1; &#xBC15;&#xD0C8;&#xB41C; &#xC218;&#xC5FC; &#xC751;&#xB2F5;&#xC758; &#xC57D;&#xD654;&#xC5D0; &#xACBD;&#xD5D8; &#xC885;&#xC18D; &#xC18C;&#xC131; &#xC218; &#xC5C6;&#xC2B5;&#xB2C8;&#xB2E4;. P25 &#xD6C4; CB1 &#xBD09;&#xC1C4; &#xC9C0;&#xB3C4; &#xAC1C;&#xBC1C; &#xB610;&#xB294; &#xC18C;&#xC131;&#xC744; &#xBC29;&#xD574; &#xD558;&#xC9C0; &#xC54A;&#xC558;&#xB2E4;. AM251 &#xC18C;&#xC131; &#xD6A8;&#xACFC; &#xCD1D; &#xD65C;&#xB3D9; &#xBCC0;&#xD654;&#xB97C; &#xBCF4;&#xC870; &#xD588;&#xB2E4; &#xC81C;&#xC548; &#xAC10;&#xAC01; &#xAC16;&#xB294; &#xC694;&#xB3D9; &#xD558; &#xACE0; &#xC720;&#xC77C;&#xD55C; &#xACB8;&#xC190; &#xD558; &#xAC8C; &#xC601;&#xD5A5;&#xC744; &#xBC1B;&#xB294; &#xD544;&#xB4DC; &#xC804;&#xC704;&#xC5D0; &#xC2EC;&#xAC01;&#xD55C; &#xC601;&#xD5A5;&#xC744; &#xD588;&#xB2E4;. &#xC774;&#xB7EC;&#xD55C; &#xC5F0;&#xAD6C; &#xACB0;&#xACFC; &#xC2DC;&#xC2A4;&#xD15C; &#xC218;&#xC900; &#xAC1C;&#xBC1C;&#xC5D0;&#xC11C; CB1 &#xC885;&#xC18D; &#xC18C;&#xC131; &#xBC0F; &#xC218;&#xC5FC; &#xB9F5;&#xC758; &#xCD08;&#xAE30; &#xC0B0; &#xD6C4; &#xC18C;&#xC131; &#xC5F0;&#xB8E8;.

Endocannabinoid &#xC2E0;&#xD638;&#xB294; somatosensory &#xD53C; &#xC9C8;&#xC5D0;&#xC11C; &#xAC1C;&#xBC1C;&#xACFC; &#xC218;&#xC5FC; &#xC9C0;&#xB3C4;&#xC758; &#xC911;&#xC694; &#xD55C; &#xAE30;&#xAC04;&#xAC00; &#xC18C;&#xC131;&#xC5D0; &#xB300; &#xD55C; &#xD544;&#xC694; &#xD569;&#xB2C8;&#xB2E4;.

Receptores de cannabinoides (CB1) tipo 1 median plasticidad sin&aacute;ptica generalizada, pero no est&aacute; claro c&oacute;mo esto contribuye a la plasticidad de nivel de sistemas y desarrollo in vivo. Probamos si se&ntilde;alizaci&oacute;n CB1 es necesaria para el desarrollo y la plasticidad del mapa barba en la corteza somatosensorial de rata. Tratamiento con la barba de CB1 antagonista AM251 durante un per&iacute;odo cr&iacute;tico para capa (L) 2/3 Desarrollo (principio d&iacute;a postnatal [P] 12-16) interrumpi&oacute; mapa desarrollo, llevando a barba inadecuado templar en L2/3 columna bordes y mapa borroso. Tratamiento temprano de la AM251 tambi&eacute;n impidi&oacute; plasticidad dependiente de la experiencia en L2/3, incluyendo debilitamiento inducida por la deprivaci&oacute;n de la sinapsis y debilitamiento de las respuestas privadas barba. Bloqueo de CB1 despu&eacute;s P25 no interrumpir desarrollo de mapa o plasticidad. AM251 no afect&oacute; aguda sensorial-evocado clavar y &uacute;nico campo modestamente afectados potenciales, sugiriendo que los efectos de plasticidad no eran secundarias a cambios de actividad. Estos resultados implican plasticidad CB1-dependiente en el desarrollo de sistemas de nivel y plasticidad postnatal temprana del mapa de barba.

Endocannabinoide es necesaria la se&ntilde;alizaci&oacute;n para el desarrollo y plasticidad per&iacute;oda cr&iacute;tica del mapa de barba en la corteza somatosensorial.

The whisker somatosensory system in awake, behaving rodents is a powerful model for studying neurobiology of sensation, from molecules to circuits to behavior. Recent studies reveal how key tactile features are detected in awake animals and encoded by spike trains in somatosensory cortex (S1). Here we summarize progress on detection of surface texture (roughness). Texture appears to be inferred from the statistics of complex, irregular whisker micromotion on surfaces, specifically by mean speed or by patterns of discrete, high-velocity whisker slips. These are encoded in S1 by mean firing rate and by sparse, synchronous, slip-evoked spike volleys, respectively. An alternative model of place coding for texture based on differential whisker resonance is less well supported, but is not ruled out.

Texture coding in the whisker system.

The hippocampus is required for the encoding, consolidation and retrieval of event memories. Although the neural mechanisms that underlie these processes are only partially understood, a series of recent papers point to awake memory replay as a potential contributor to both consolidation and retrieval. Replay is the sequential reactivation of hippocampal place cells that represent previously experienced behavioral trajectories and occurs frequently in the awake state, particularly during periods of relative immobility. Awake replay may reflect trajectories through either the current environment or previously visited environments that are spatially remote. The repetition of learned sequences on a compressed time scale is well suited to promote memory consolidation in distributed circuits beyond the hippocampus, suggesting that consolidation occurs in both the awake and sleeping animal. Moreover, sensory information can influence the content of awake replay, suggesting a role for awake replay in memory retrieval.

Hippocampal replay in the awake state: a potential substrate for memory consolidation and retrieval.

The rodent whisker system is a major model for understanding neural mechanisms for tactile sensation of surface texture (roughness). Rats discriminate surface texture using the whiskers, and several theories exist for how texture information is physically sensed by the long, moveable macrovibrissae and encoded in spiking of neurons in somatosensory cortex. However, evaluating these theories requires a psychometric curve for texture discrimination, which is lacking. Here we trained rats to discriminate rough vs. fine sandpapers and grooved vs. smooth surfaces. Rats intermixed trials at macrovibrissa contact distance (nose >2 mm from surface) with trials at shorter distance (nose <2 mm from surface). Macrovibrissae were required for distant contact trials, while microvibrissae and non-whisker tactile cues were used for short distance trials. A psychometric curve was measured for macrovibrissa-based sandpaper texture discrimination. Rats discriminated rough P150 from smoother P180, P280, and P400 sandpaper (100, 82, 52, and 35 Âµm mean grit size, respectively). Use of olfactory, visual, and auditory cues was ruled out. This is the highest reported resolution for rodent texture discrimination, and constrains models of neural coding of texture information.

Psychometric curve and behavioral strategies for whisker-based texture discrimination in rats.

The hippocampus is critical for spatial learning and memory. Hippocampal neurons in awake animals exhibit place field activity that encodes current location, as well as sharp-wave ripple (SWR) activity during which representations based on past experiences are often replayed. The relationship between these patterns of activity and the memory functions of the hippocampus is poorly understood. We interrupted awake SWRs in animals learning a spatial alternation task. We observed a specific learning and performance deficit that persisted throughout training. This deficit was associated with awake SWR activity, as SWR interruption left place field activity and post-experience SWR reactivation intact. These results provide a link between awake SWRs and hippocampal memory processes, which suggests that awake replay of memory-related information during SWRs supports learning and memory-guided decision-making.

Article	Year
Somatosensory integration controlled by dynamic thalamocortical feed-forward inhibition. Neuron\| PubMed ID: 16242411	2005
Sparse temporal coding of elementary tactile features during active whisker sensation. Nature neuroscience\| PubMed ID: 19430473	2009
Reactivating memories for consolidation. Neuron\| PubMed ID: 19555641	2009
Endocannabinoid signaling is required for development and critical period plasticity of the whisker map in somatosensory cortex. Neuron\| PubMed ID: 19945395	2009
Texture coding in the whisker system. Current opinion in neurobiology\| PubMed ID: 20299205	2010
Hippocampal replay in the awake state: a potential substrate for memory consolidation and retrieval. Nature neuroscience\| PubMed ID: 21270783	2011
Psychometric curve and behavioral strategies for whisker-based texture discrimination in rats. PloS one\| PubMed ID: 21673811	2011
Awake hippocampal sharp-wave ripples support spatial memory. Science (New York, N.Y.)\| PubMed ID: 22555434	2012

Shantanu P. Jadhav

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