This work is supported by a grant (1R01MH094449-01A1) from the National Institute of Mental Health to Y.Z.&#160;

Experiments described in this manuscript were performed in accordance with the guidelines and regulations set forth by the University of California, Santa Cruz Institutional Animal Care and Use Committee.
1. Setup (Also See Materials List)
<ol>
	<li>Use millet seeds as food pellets.</li>
	<li>Use a custom-made clear Plexiglas&#160;training chamber (20 cm tall, 15 cm deep, and 8.5 cm wide, measured from outside, with the thickness of the Plexiglas 0.5 cm) that contains three vertical slits (one slit on &#39;shaping&#39; edge, and two slits on the opposite &#39;training&#39; edge). The vertical slits should be 0.5 cm wide and 13 cm tall and be located on the front wall of the box: in the center, on the left side, and on the right side (Figure 1A).</li>
	<li>Use a tilted tray to hold the seeds used during shaping sessions. The tray can be custom-made from three glass slides (Figure 1B).</li>
	<li>Prepare a food platform (8.5 cm long, 4.4 cm wide, and 0.9 cm tall). This food platform is placed in the front side (facing the trainer) of the training chamber during training sessions. There are two divot slots on the food platform for positioning seeds, one slot on the left, and the other slot on the right side. The divots are 0.3 cm from the long edge, and 2.4 cm from the width edge (Figure 1C). The left and right divot slots correspond to the left and right slit in the mouse training chamber and are used for training of dominant forelimbs. The purpose of having these divot slots is to ensure that the seed is placed consistently at the same place for each reaching attempt.</li>
	<li>During sessions have in hand a pair of forceps, weighing scale, and stopwatch.</li>
</ol>
2. Food Deprivation (2 Days)
<ol>
	<li>Weigh each mouse to obtain a baseline bodyweight before food deprivation.</li>
	<li>Food-restrict mice for 2 days to initiate bodyweight loss. As a general starting point, mice are given 0.1 g of food per 1 g bodyweight per day (e.g.&#160;a mouse weighing 15 g, we usually start with 1.5 g of food). Adjust the amount of food based on the baseline bodyweight, the rate of weight loss, sex, and age of mice. While the bodyweight may continue to decrease a little more during the shaping phase, such reduced body weight (i.e.&#160;~90% of the original baseline weight) should be maintained throughout training (Figures 2A and 2B). The amount of food necessary to maintain the mouse&#39;s body weight is typically the same as the amount used in restriction.</li>
</ol>
3. Shaping (3-7 Days)
<ol>
	<li>Group habitat acclimatization (Day 1): Put two mice into the training chamber at the same time. Place approximately 20 seeds/mouse inside the chamber for their consumption. Allow the mice to stay in the chamber for 20 min and then put them back into their home cage.</li>
	<li>Individual habitat acclimatization (Day 2): The same setup as in step&#160;3.1, but place mice into the training chamber individually. The purpose of group and individual habitat acclimatization is to get the mice familiar with both the training chamber and the millet seeds.</li>
	<li>Determination of forelimb dominance (Day 3 and later): Place the single slit side of the training chamber facing downwards (Figure 1D). Fill the food tray with seeds. Press the food tray up against the front wall of the training chamber to allow the seeds accessible to the mouse. Place mice into the cage individually. If they are sufficiently interested in the seeds located on the food tray, they would plow through the slit to get the seed inside. They will then pick up the seeds and consume them. &#39;Shaping&#39; is considered finished when both of the following criteria are met: 1) the mouse conducts 20 reaching attempts within 20 min, and 2) more than 70% reaches are performed with one forelimb.</li>
</ol>
Notes:
<ol>
	<li>If the mouse uses its tongue to get the seeds into the chamber, move the tray back from the slit slightly. The increase in reaching distance discourages the mouse to use its tongue to acquire the seed and therefore facilitates its forelimb reaching.</li>
	<li>If the mouse cannot finish shaping within a week, drop it from the experiment.</li>
</ol>
4. Training (8+ Days)
<ol>
	<li>Place the double-slit side of the training chamber facing downwards (Figure 1E).</li>
	<li>Place the mice in the cage individually. Put individual seeds on the food platform in the divot corresponding to the preferred paw (i.e.&#160;for the right-handed mouse, use the slit on the mouse&#39;s right side).</li>
	<li>Observe mouse reaching behavior and score according to the following categories:
	<ol>
		<li>Success: The mouse reaches with preferred paw, grasps and retrieves the seed, and feeds it into its mouth.</li>
		<li>Drop: The mouse reaches with preferred paw, grasps the seed, but drops it before putting it into its mouth.</li>
		<li>Fail: The mouse reaches with preferred paw towards the seed, but it either misses the seed or knocks it off from the holding plate.</li>
	</ol>
	</li>
	<li>Train the mice for 30 reaching attempts on the preferred limb or 20 min (whichever comes first) per day.</li>
	<li>Place the mice back to their home cage after training and provide daily food quantum.</li>
</ol>
Notes:
<ol>
	<li>In some cases, mice reach even when there is no seed placed on the food platform. Such reaches are considered &#34;in-vain reaches&#34; and are not counted towards the total number of reaching attempts. To discourage &#34;in-vain reaches&#34;, train mice to walk back to the other end of the training chamber before placing the next seed. A similar strategy has been used in rats for a similar behavioral task21. Mice sometimes also reach with nonpreferred paw in the presence of the seed. These reaches are considered &#39;contralateral reaches&#39; and do not count&#160;towards the total number of reaches either.</li>
	<li>To limit behavioral variations due to the fluctuations in circadian rhythm, perform all shaping and training sessions at the same time of the day, during normal waking hours for mice.</li>
	<li>To avoid &#160;behavioral variation due to different trainers, make sure the same person trains the same mice throughout the experiment.</li>
	<li>Attention of mice is critical for this behavioral test. Train mice in a separate and quiet room to minimize environmental perturbation.</li>
	<li>Mice can be trained with more than 30 reaches daily (e.g.&#160;50 reaches). Increasing the number of reaching attempts makes it possible to examine behavioral improvement within the same training session.</li>
</ol>
5. Data Quantification
There are many ways to quantify mouse behavior following training. Two most straight-forward analyses are:
<ol>
	<li>Success rate = successful reaches over total reaching attempts, presented as percentages. Drop and failure rates can be plotted the same way.</li>
	<li>Speed of success = number of successful attempts divided by time, presented as successful reaches per minute. In most cases, the speed of success continues to increase, even when the success rate attains the plateau.</li>
</ol>

<ol>
	<li>Schmidt, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Motor+Learning+Principles+for+Physical+Therapy.">Motor Learning Principles for Physical Therapy.</a> Foundations for Physical Therapy. Contemporary Management of Motor Control Problems, Proceedings of the II STEP Conference. , 49-63 (1991).</li><li>Honda, M., Deiber, M. P., Ibanez, V., Pascual-Leone, A., Zhuang, P., Hallett, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+cortical+involvement+in+implicit+and+explicit+motor+sequence+learning.+A+PET+study..">Dynamic cortical involvement in implicit and explicit motor sequence learning. A PET study..</a> Brain. 121, 2159-2173 (1998).</li><li>Karni, A., Meyer, G., Jezzard, P., Adams, M. M., Turner, R., Ungerleider, L. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+MRI+evidence+for+adult+motor+cortex+plasticity+during+motor+skill+learning.">Functional MRI evidence for adult motor cortex plasticity during motor skill learning.</a> Nature. 377, 155-158 (1995).</li><li>Karni, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+acquisition+of+skilled+motor+performance:+fast+and+slow+experience-driven+changes+in+primary+motor+cortex.">The acquisition of skilled motor performance: fast and slow experience-driven changes in primary motor cortex.</a> Proc. Natl Acad. Sci. U.S.A. 95, 861-868 (1998).</li><li>Muellbacher, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+consolidation+in+human+primary+motor+cortex.">Early consolidation in human primary motor cortex.</a> Nature. 415, 640-644 (2002).</li><li>Kleim, J. A., Hogg, T. M., VandenBerg, P. M., Cooper, N. R., Bruneau, R., Remple, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cortical+synaptogenesis+and+motor+map+reorganization+occur+during+late,+but+not+early,+phase+of+motor+skill+learning.">Cortical synaptogenesis and motor map reorganization occur during late, but not early, phase of motor skill learning.</a> J. Neurosci. 24, 628-633 (2004).</li><li>Rioult-Pedotti, M. S., Friedman, D., Donoghue, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Learning-induced+LTP+in+neocortex.">Learning-induced LTP in neocortex.</a> Science. 290, 533-536 (2000).</li><li>Rioult-Pedotti, M. S., Friedman, D., Hess, G., Donoghue, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strengthening+of+horizontal+cortical+connections+following+skill+learning.">Strengthening of horizontal cortical connections following skill learning.</a> Nat. Neurosci. 1, 230-234 (1998).</li><li>Farr, T. D., Whishaw, I. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+and+qualitative+impairments+in+skilled+reaching+in+the+mouse+(Mus+musculus)+after+a+focal+motor+cortex+stroke.">Quantitative and qualitative impairments in skilled reaching in the mouse (Mus musculus) after a focal motor cortex stroke.</a> Stroke J. Cereb. Circ. 33, 1869-1875 (2002).</li><li>Huang, V. S., Haith, A., Mazzoni, P., Krakauer, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rethinking+motor+learning+and+savings+in+adaptation+paradigms:+model-free+memory+for+successful+actions+combines+with+internal+models.">Rethinking motor learning and savings in adaptation paradigms: model-free memory for successful actions combines with internal models.</a> Neuron. 70, 787-801 (2011).</li><li>Smith, M. A., Ghazizadeh, A., Shadmehr, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interacting+adaptive+processes+with+different+timescales+underlie+short-term+motor+learning.">Interacting adaptive processes with different timescales underlie short-term motor learning.</a> PLoS Biol. 4, (2006).</li><li>Pavlides, C., Miyashita, E., Asanuma, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Projection+from+the+sensory+to+the+motor+cortex+is+important+in+learning+motor+skills+in+the+monkey.">Projection from the sensory to the motor cortex is important in learning motor skills in the monkey.</a> J. Neurophysiol. 70, 733-741 (1993).</li><li>Paz, R., Boraud, T., Natan, C., Bergman, H., Vaadia, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparatory+activity+in+motor+cortex+reflects+learning+of+local+visuomotor+skills.">Preparatory activity in motor cortex reflects learning of local visuomotor skills.</a> Nat. Neurosci. 6, 882-890 (2003).</li><li>Paz, R., Vaadia, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Learning-induced+improvement+in+encoding+and+decoding+of+specific+movement+directions+by+neurons+in+the+primary+motor+cortex.">Learning-induced improvement in encoding and decoding of specific movement directions by neurons in the primary motor cortex.</a> PLoS Biol. 2, (2004).</li><li>Plautz, E. J., Milliken, G. W., Nudo, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+repetitive+motor+training+on+movement+representations+in+adult+squirrel+monkeys:+role+of+use+versus+learning.">Effects of repetitive motor training on movement representations in adult squirrel monkeys: role of use versus learning.</a> Neurobiol. Learn. Mem. 74, 27-55 (2000).</li><li>Hosp, J. A., Pekanovic, A., Rioult-Pedotti, M. S., Luft, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dopaminergic+projections+from+midbrain+to+primary+motor+cortex+mediate+motor+skill+learning.">Dopaminergic projections from midbrain to primary motor cortex mediate motor skill learning.</a> J. Neurosci. 31, 2481-2487 (2011).</li><li>Adkins, D. L., Boychuk, J., Remple, M. S., Kleim, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Motor+training+induces+experience-specific+patterns+of+plasticity+across+motor+cortex+and+spinal+cord.">Motor training induces experience-specific patterns of plasticity across motor cortex and spinal cord.</a> 101, 1776-1782 (2006).</li><li>Whishaw, I. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+endpoint,+descriptive,+and+kinematic+comparison+of+skilled+reaching+in+mice+(Mus+musculus)+with+rats+(Rattus+norvegicus).">An endpoint, descriptive, and kinematic comparison of skilled reaching in mice (Mus musculus) with rats (Rattus norvegicus).</a> Behav. Brain Res. 78, 101-111 (1996).</li><li>Xu, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+formation+and+selective+stabilization+of+synapses+for+enduring+motor+memories.">Rapid formation and selective stabilization of synapses for enduring motor memories.</a> Nature. 462, 915-919 (2009).</li><li>Fu, M., Yu, X., Lu, J., Zuo, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Repetitive+motor+learning+induces+coordinated+formation+of+clustered+dendritic+spines+in+vivo.">Repetitive motor learning induces coordinated formation of clustered dendritic spines in vivo.</a> Nature. 483, 92-95 (2012).</li><li>Whishaw, I. Q., Whishaw, P., Gorny, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+structure+of+skilled+forelimb+reaching+in+the+rat:+a+movement+rating+scale.">The structure of skilled forelimb reaching in the rat: a movement rating scale.</a> J .Vis. Exp. , (2008).</li><li>Bailey, K. R., Crawley, J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anxiety-Related+Behavior+in+Mice.">Anxiety-Related Behavior in Mice.</a> In Buccafusco JJ (Ed.) Methods of Behavior Analysis in Neuroscience. Chapter 5, 2nd ed. , (2009).</li><li>Yu, X., Zuo, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spine+plasticity+in+the+motor+cortex.">Spine plasticity in the motor cortex.</a> Curr. Opin. Neurobiol. 21, 169-174 (2011).</li><li>Qian, Y., Chen, M., Forssberg, H., Diaz Heijtz, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+variation+in+dopamine-related+gene+expression+influences+motor+skill+learning+in+mice.">Genetic variation in dopamine-related gene expression influences motor skill learning in mice.</a> Genes Brain Behav. 12, 604-614 (2013).</li><li>MacLellan, C. L., Gyawali, S., Colbourne, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Skilled+reaching+impairments+follow+intrastriatal+hemorrhagic+stroke+in+rats.">Skilled reaching impairments follow intrastriatal hemorrhagic stroke in rats.</a> Behav. Brain Res. 175, 82-89 (2006).</li><li>Hong, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reduced+hippocampal+neurogenesis+and+skill+reaching+performance+in+adult+Emx1+mutant+mice.">Reduced hippocampal neurogenesis and skill reaching performance in adult Emx1 mutant mice.</a> Exp. Neurol. 206, 24-32 (2007).</li><li>Bureau, G., Carrier, M., Lebel, M., Cyr, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intrastriatal+inhibition+of+extracellular+signal-regulated+kinases+impaired+the+consolidation+phase+of+motor+skill+learning.">Intrastriatal inhibition of extracellular signal-regulated kinases impaired the consolidation phase of motor skill learning.</a> Neurobiol. Learn. Mem. 94, 107-115 (2010).</li><li>McCormick, D. A., Lavond, D. G., Thompson, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuronal+responses+of+the+rabbit+brainstem+during+performance+of+the+classically+conditioned+nictitating+membrane+(NM)/eyelid+response.">Neuronal responses of the rabbit brainstem during performance of the classically conditioned nictitating membrane (NM)/eyelid response.</a> Brain Res. 271, 73-88 (1983).</li><li>Molinari, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebellum+and+procedural+learning:+evidence+from+focal+cerebellar+lesions.">Cerebellum and procedural learning: evidence from focal cerebellar lesions.</a> Brain. 120, 1753-1762 (1997).</li><li>Willuhn, I., Steiner, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Motor-skill+learning+in+a+novel+running-wheel+task+is+dependent+on+D1+dopamine+receptors+in+the+striatum.">Motor-skill learning in a novel running-wheel task is dependent on D1 dopamine receptors in the striatum.</a> Neuroscience. 153, 249-258 (2008).</li></ol>

The authors declare no conflict of interest.

Importance of the shaping phase:
Because of increased anxiety from being in an unknown environment, it is usually difficult for mice to be trained in a novel environment21,22. Therefore, the goal of shaping is to familiarize mice with the training chamber, the trainer&#160;(i.e.&#160;reduce their anxiety levels), and the task requirements (i.e.&#160;to identify seed as food source). Another goal of the shaping is to determine the preferred limbs of individual mice for...

Understanding the mechanisms underlying learning and memory is one of the biggest challenges in neuroscience. In the motor system, the acquisition of novel motor skills with practice is often referred as motor learning, whereas the retention of previously learned motor skills is regarded as motor memory1. Learning a new motor skill is usually reflected in improvement of desired motor performance over time, until a point when the motor skill is either perfected or satisfactorily consistent. For most cases, the acquired motor memory can persist for a long period of time, even in the absence of practice. In humans, neuroimaging studies using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have shown that primary motor cortex (M1) activity changes during the acquisition phase of motor skill learning2-4, and temporary interference of M1 activity by low frequency transcranial magnetic stimulation leads to significantly disrupted retention of motor behavioral improvement5. Similarly, forelimb-specific training in rats induces functional and anatomical plasticity in the M1, exemplified by the increase of both c-fos activity and synapse/neuron ratio in the M1 contralateral to the trained forelimb during the late phase of motor skill learning6. Furthermore, a similar training paradigm also strengthens layer 2/3 horizontal connections in the contralateral M1 corresponding to the trained forelimb, resulting in reduced long term potentiation (LTP) and enhanced long term depression (LTD) after rats acquire the tasks7. Such synaptic modification, however, is not observed in the M1 cortical regions corresponding to untrained forelimb or hindlimbs8. Alternatively, when the M1 is damaged through stroke, there are dramatic deficiencies in forelimb specific motor-skills9. While most of the motor behavioral studies have been conducted on humans, monkeys, and rats2-8,10-17, mice become an attractive model system because of its powerful genetics and low cost.
Here we present a forelimb specific motor-skill learning paradigm: a single-pellet reaching task. In this paradigm, mice are trained to extend their forelimbs through a narrow slit to grasp and retrieve food pellets (millet seeds) positioned at a fixed location, a behavior analogous to learning archery, dart-throwing, and shooting basketballs in human. This reaching task has been modified from previous rat studies that have shown similar results between mice&#160;and rats18. Using two-photon transcranial imaging, our previous work has followed the dynamics of dendritic spines (postsynaptic structures for majority excitatory synapses) over time during this training. We found that a single training session led to rapid emergence of new dendritic spines on pyramidal neurons in the motor cortex contralateral to the trained forelimb. Subsequent training of the same reaching task preferentially stabilized these learning-induced spines, which persisted long after training terminated19. Furthermore, spines that emerged during repetitions of reaching task tended to cluster along dendrites, whereas spines formed during tandem execution of reaching task and another forelimb-specific motor task (i.e.&#160;the pasta handling task) did not cluster20.
In the present video, we describe step-by-step the setup of this behavioral paradigm, from the initial food deprivation to shaping, and to motor training. We also describe the common behaviors of mice during the process of executing this behavioral paradigm, and how these behaviors are categorized and analyzed. Finally, we discuss the precautionary measures needed to practice such a learning paradigm and the issues that may be encountered during data analyses.

<table border="0" cellpadding="0" cellspacing="0" width="856">
	<colgroup>
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">Training chamber in clear acrylic box</td>
			<td style="width:595px;">For dimensions, see Fig. 1A</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">Tilted tray for shaping</td>
			<td>custom-made from glass slides, see Fig. 1B</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">Food platform for training</td>
			<td>For dimensions, see Fig. 1C</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">Millet seeds&#160;</td>
			<td>filtered from &#8220;Wild Bird Food Dove and Quail Blend Wild Bird Food (All Living Things)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">Forceps</td>
			<td>For placing the seeds</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">A weighing scale</td>
			<td>For daily body weight measurement</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">A stopwatch</td>
			<td>For time measurement during shaping/training sessions</td>
		</tr>
	</tbody>
</table>

study motor skill learning by single-pellet reaching tasks in mice

Reaching for and retrieving objects require precise and coordinated motor movements in the forelimb. When mice are repeatedly trained to grasp and retrieve food rewards positioned at a specific location, their motor performance (defined as accuracy and speed) improves progressively over time, and plateaus after persistent training. Once such reaching skill is mastered, its further maintenance does not require constant practice. Here we introduce a single-pellet reaching task to study the acquisition and maintenance of skilled forelimb movements in mice. In this video, we first describe the behaviors of mice that are commonly encountered in this learning and memory paradigm, and then discuss how to categorize these behaviors and quantify the observed results. Combined with mouse genetics, this paradigm can be utilized as a behavioral platform to explore the anatomical underpinnings, physiological properties, and molecular mechanisms of learning and memory.

Learning curve:
Mastery of a motor skill often requires persistent practice over time. A typical averaged learning curve is composed of two phases: an initial acquisition phase during which the success rate improves progressively, and a later consolidation phase when the success rate reaches the plateau (Figure 2C). It should be noted the learning curves of individual mice vary; different mice take different numbers of days to reach the plateau level, and the individual learning ...

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Study Motor Skill Learning by Single-pellet Reaching Tasks in Mice

Persistent practice improves the precision of coordinated movements.&#160;Here we introduce a single-pellet reaching task, which is designed to assess the learning and memory of forelimb skill in mice.&#160;

Reaching for and retrieving objects require precise and coordinated motor movements in the forelimb. When mice are repeatedly trained to grasp and ...

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20.6K Views.  University of California, Santa Cruz. Persistent practice improves the precision of coordinated movements. Here we introduce a single-pellet reaching task, which is designed to assess the learning and memory of forelimb skill in mice. 

Video: Study Motor Skill Learning by Single-pellet Reaching Tasks in Mice

Compensatory Limb Use and Behavioral Assessment of Motor Skill Learning Following Sensorimotor Cortex Injury in a Mouse Model of Ischemic Stroke

Mouse models have become increasingly popular in the field of behavioral neuroscience, and specifically in studies of experimental stroke. As models advance, it is important to develop sensitive behavioral measures specific to the mouse. The present protocol describes a skilled motor task for use in mouse models of stroke. The Pasta Matrix Reaching Task functions as a versatile and sensitive behavioral assay that permits experimenters to collect accurate outcome data and manipulate limb use to mimic human clinical phenomena including compensatory strategies (i.e., learned non-use) and focused rehabilitative training. When combined with neuroanatomical tools, this task also permits researchers to explore the mechanisms that support behavioral recovery of function (or lack thereof) following stroke. The task is both simple and affordable to set up and conduct, offering a variety of training and testing options for numerous research questions concerning functional outcome following injury. Though the task has been applied to mouse models of stroke, it may also be beneficial in studies of functional outcome in other upper extremity injury models.

Mouse models have become increasingly popular in studies of behavioral neuroscience. As models advance, it is important to develop sensitive behavioral measures specific to the mouse. This protocol describes the Pasta Matrix Reaching Task, which is a skilled motor task for use in mouse models of stroke.

Mouse models have become increasingly popular in the field of behavioral neuroscience, and specifically in studies of experimental stroke. As models ...

Uncovering Beat Deafness: Detecting Rhythm Disorders with Synchronized Finger Tapping and Perceptual Timing Tasks

A set of behavioral tasks for assessing perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) is presented here with the goal of uncovering rhythm disorders, such as beat deafness. Beat deafness is characterized by poor performance in perceiving durations in auditory rhythmic patterns or poor synchronization of movement with auditory rhythms (e.g., with musical beats). These tasks include the synchronization of finger tapping to the beat of simple and complex auditory stimuli and the detection of rhythmic irregularities (anisochrony detection task) embedded in the same stimuli. These tests, which are easy to administer, include an assessment of both perceptual and sensorimotor timing abilities under different conditions (e.g., beat rates and types of auditory material) and are based on the same auditory stimuli, ranging from a simple metronome to a complex musical excerpt. The analysis of synchronized tapping data is performed with circular statistics, which provide reliable measures of synchronization accuracy (e.g., the difference between the timing of the taps and the timing of the pacing stimuli) and consistency. Circular statistics on tapping data are particularly well-suited for detecting individual differences in the general population. Synchronized tapping and anisochrony detection are sensitive measures for identifying profiles of rhythm disorders and have been used with success to uncover cases of poor synchronization with spared perceptual timing. This systematic assessment of perceptual and sensorimotor timing can be extended to populations of patients with brain damage, neurodegenerative diseases (e.g., Parkinson&#8217;s disease), and developmental disorders (e.g., Attention Deficit Hyperactivity Disorder).

Behavioral tasks that allow for the assessment of perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) are presented. Synchronization of finger tapping to the beat of an auditory stimuli and detecting rhythmic irregularities provides a means of uncovering rhythm disorders.

A set of behavioral tasks for assessing perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) is presented here ...

Performing Behavioral Tasks in Subjects with Intracranial Electrodes

Patients having stereo-electroencephalography (SEEG) electrode, subdural grid or depth electrode implants have a multitude of electrodes implanted in different areas of their brain for the localization of their seizure focus and eloquent areas. After implantation, the patient must remain in the hospital until the pathological area of brain is found and possibly resected. During this time, these patients offer a unique opportunity to the research community because any number of behavioral paradigms can be performed to uncover the neural correlates that guide behavior. Here we present a method for recording brain activity from intracranial implants as subjects perform a behavioral task designed to assess decision-making and reward encoding. All electrophysiological data from the intracranial electrodes are recorded during the behavioral task, allowing for the examination of the many brain areas involved in a single function at time scales relevant to behavior. Moreover, and unlike animal studies, human patients can learn a wide variety of behavioral tasks quickly, allowing for the ability to perform more than one task in the same subject or for performing controls. Despite the many advantages of this technique for understanding human brain function, there are also methodological limitations that we discuss, including environmental factors, analgesic effects, time constraints and recordings from diseased tissue. This method may be easily implemented by any institution that performs intracranial assessments; providing the opportunity to directly examine human brain function during behavior.

Patients implanted with intracranial electrodes provide a unique opportunity to record neurological data from multiple areas of the brain while the patient performs behavioral tasks. Here, we present a method of recording from implanted patients that can be reproducible at other institutions with access to this patient population.

Patients having stereo-electroencephalography (SEEG) electrode, subdural grid or depth electrode implants have a multitude of electrodes implanted in ...

Functional Near Infrared Spectroscopy of the Sensory and Motor Brain Regions with Simultaneous Kinematic and EMG Monitoring During Motor Tasks

There are several advantages that functional near-infrared spectroscopy (fNIRS) presents in the study of the neural control of human movement. It is relatively flexible with respect to participant positioning and allows for some head movements during tasks. Additionally, it is inexpensive, light weight, and portable, with very few contraindications to its use. This presents a unique opportunity to study functional brain activity during motor tasks in individuals who are typically developing, as well as those with movement disorders, such as cerebral palsy. An additional consideration when studying movement disorders, however, is the quality of actual movements performed and the potential for additional, unintended movements. Therefore, concurrent monitoring of both blood flow changes in the brain and actual movements of the body during testing is required for appropriate interpretation of fNIRS results. Here, we show a protocol for the combination of fNIRS with muscle and kinematic monitoring during motor tasks. We explore gait, a unilateral multi-joint movement (cycling), and two unilateral single-joint movements (isolated ankle dorsiflexion, and isolated hand squeezing). The techniques presented can be useful in studying both typical and atypical motor control, and can be modified to investigate a broad range of tasks and scientific questions.

Monitoring brain activity during upright motor tasks is of great value when investigating the neural source of movement disorders. Here, we demonstrate a protocol that combines functional near infrared spectroscopy with continuous monitoring of muscle and kinematic activity during 4 types of motor tasks.

There are several advantages that functional near-infrared spectroscopy (fNIRS) presents in the study of the neural control of human movement. It is ...

Acquisition of a High-precision Skilled Forelimb Reaching Task in Rats

Movements are the main measurable output of central nervous system function. Developing behavioral paradigms that allow detailed analysis of motor learning and execution is of critical importance in order to understand the principles and processes that underlie motor function. Here we present a paradigm to study movement acquisition within a daily session of training (within-session) representing the fast learning component and primary acquisition as well as skilled motor learning over several training sessions (between-session) representing the slow learning component and consolidation of the learned task. This behavioral paradigm increases the degree of difficulty and complexity of the motor skill task due to two features: First, the animal realigns its body prior to each pellet retrieval forcing renewed orientation and preventing movement execution from the same angle. Second, pellets are grasped from a vertical post that matches the diameter of the pellet and is placed in front of the cage. This requires a precise grasp for successful pellet retrieval and thus prevents simple pulling of the pellet towards the animal. In combination with novel genetics, imaging and electrophysiological technologies, this behavioral method will aid to understand the morphological, anatomical and molecular underpinnings of motor learning and memory.

A paradigm is presented to analyze the acquisition of a high-precision skilled forelimb reaching task in rats.

Movements are the main measurable output of central nervous system function. Developing behavioral paradigms that allow detailed analysis of motor ...

Investigating Motor Skill Learning Processes with a Robotic Manipulandum

Skilled reaching tasks are commonly used in studies of motor skill learning and motor function under healthy and pathological conditions, but can be time-intensive and ambiguous to quantify beyond simple success rates. Here, we describe the training procedure for reach-and-pull tasks with ETH Pattus, a robotic platform for automated forelimb reaching training that records pulling and hand rotation movements in rats. Kinematic quantification of the performed pulling attempts reveals the presence of distinct temporal profiles of movement parameters such as pulling velocity, spatial variability of the pulling trajectory, deviation from midline, as well as pulling success. We show how minor adjustments in the training paradigm result in alterations in these parameters, revealing their relation to task difficulty, general motor function or skilled task execution. Combined with electrophysiological, pharmacological and optogenetic techniques, this paradigm can be used to explore the mechanisms underlying motor learning and memory formation, as well as loss and recovery of function (e.g. after stroke).

A paradigm is presented for training and analysis of an automated skilled reaching task in rats. Analysis of pulling attempts reveals distinct subprocesses of motor learning.

Skilled reaching tasks are commonly used in studies of motor skill learning and motor function under healthy and pathological conditions, but can be ...

Using a Split-belt Treadmill to Evaluate Generalization of Human Locomotor Adaptation

Understanding the mechanisms underlying locomotor learning helps researchers and clinicians optimize gait retraining as part of motor rehabilitation. However, studying human locomotor learning can be challenging. During infancy and childhood, the neuromuscular system is quite immature, and it is unlikely that locomotor learning during early stages of development is governed by the same mechanisms as in adulthood. By the time humans reach maturity, they are so proficient at walking that it is difficult to come up with a sufficiently novel task to study de novo locomotor learning. The split-belt treadmill, which has two belts that can drive each leg at a different speed, enables the study of both short- (i.e., immediate) and long-term (i.e., over minutes-days; a form of motor learning) gait modifications in response to a novel change in the walking environment. Individuals can easily be screened for previous exposure to the split-belt treadmill, thus ensuring that all experimental participants have no (or equivalent) prior experience. This paper describes a typical split-belt treadmill adaptation protocol that incorporates testing methods to quantify locomotor learning and generalization of this learning to other walking contexts. A discussion of important considerations for designing split-belt treadmill experiments follows, including factors like treadmill belt speeds, rest breaks, and distractors. Additionally, potential but understudied confounding variables (e.g., arm movements, prior experience) are considered in the discussion.

We describe a protocol for investigating human locomotor adaptation using the split-belt treadmill, which has two belts that can drive each leg at a different speed. We specifically focus on a paradigm designed to test the generalization of adapted locomotor patterns to different walking contexts (e.g., gait speeds, walking environments).

Understanding the mechanisms underlying locomotor learning helps researchers and clinicians optimize gait retraining as part of motor rehabilitation. ...

Novel Object Recognition Test for the Investigation of Learning and Memory in Mice

The object recognition test (ORT) is a commonly used behavioral assay for the investigation of various aspects of learning and memory in mice. The ORT is fairly simple and can be completed over 3 days: habituation day, training day, and testing day. During training, the mouse is allowed to explore 2 identical objects. On test day, one of the training objects is replaced with a novel object. Because mice have an innate preference for novelty, if the mouse recognizes the familiar object, it will spend most of its time at the novel object. Due to this innate preference, there is no need for positive or negative reinforcement or long training schedules. Additionally, the ORT can also be modified for numerous applications. The retention interval can be shortened to examine short-term memory, or lengthened to probe long-term memory. Pharmacological intervention can be used at various times prior to training, after training, or prior to recall to investigate different phases of learning (i.e., acquisition, early or late consolidation, or recall). Overall, the ORT is a relatively low-stress, efficient test for memory in mice, and is appropriate for the detection of neuropsychological changes following pharmacological, biological, or genetic manipulations.

The object recognition test (ORT) is a simple and efficient assay for evaluating learning and memory in mice. The methodology is described below.

The object recognition test (ORT) is a commonly used behavioral assay for the investigation of various aspects of learning and memory in mice. The ORT is ...

Using Virtual Reality to Transfer Motor Skill Knowledge from One Hand to Another

As far as acquiring motor skills is concerned, training by voluntary physical movement is superior to all other forms of training (e.g. training by observation or passive movement of trainee&#39;s hands by a robotic device). This obviously presents a major challenge in the rehabilitation of a paretic limb since voluntary control of physical movement is limited. Here, we describe a novel training scheme we have developed that has the potential to circumvent this major challenge. We exploited the voluntary control of one hand and provided real-time movement-based manipulated sensory feedback as if the other hand is moving. Visual manipulation through virtual reality (VR) was combined with a device that yokes left-hand fingers to passively follow right-hand voluntary finger movements. In healthy subjects, we demonstrate enhanced within-session performance gains of a limb in the absence of voluntary physical training. Results in healthy subjects suggest that training with the unique VR setup might also be beneficial for patients with upper limb hemiparesis by exploiting the voluntary control of their healthy hand to improve rehabilitation of their affected hand.

We describe a novel virtual-reality based setup which exploits voluntary control of one hand to improve motor-skill performance in the other (non-trained) hand. This is achieved by providing real-time movement-based sensory feedback as if the non-trained hand is moving. This new approach may be used to enhance rehabilitation of patients with unilateral hemiparesis.

As far as acquiring motor skills is concerned, training by voluntary physical movement is superior to all other forms of training (e.g. training by ...

The "Motor" in Implicit Motor Sequence Learning: A Foot-stepping Serial Reaction Time Task

This protocol describes a modified serial reaction time (SRT) task used to study implicit motor sequence learning. Unlike the classic SRT task that involves finger-pressing movements while sitting, the modified SRT task requires participants to step with both feet while maintaining a standing posture. This stepping task necessitates whole body actions that impose postural challenges. The foot-stepping task complements the classic SRT task in several ways. The foot-stepping SRT task is a better proxy for the daily activities that require ongoing postural control, and thus may help us better understand sequence learning in real-life situations. In addition, response time serves as an indicator of sequence learning in the classic SRT task, but it is unclear whether response time, reaction time (RT) representing mental process, or movement time (MT) reflecting the movement itself, is a key player in motor sequence learning. The foot-stepping SRT task allows researchers to disentangle response time into RT and MT, which may clarify how motor planning and movement execution are involved in sequence learning. Lastly, postural control and cognition are interactively related, but little is known about how postural control interacts with learning motor sequences. With a motion capture system, the movement of the whole body (e.g., the center of mass (COM)) can be recorded. Such measures allow us to reveal the dynamic processes underlying discrete responses measured by RT and MT, and may aid in elucidating the relationship between postural control and the explicit and implicit processes involved in sequence learning. Details of the experimental set-up, procedure, and data processing are described. The representative data are adopted from one of our previous studies. Results are related to response time, RT, and MT, as well as the relationship between the anticipatory postural response and the explicit processes involved in implicit motor sequence learning.

The &quot;Motor&quot; in Implicit Motor Sequence Learning: A Foot-stepping Serial Reaction Time Task

We introduce the foot-stepping serial reaction time (SRT) task. This modified SRT task, complementing the classic SRT task that involves only finger-pressing movement, better approximates daily sequenced activities and allows researchers to study the dynamic processes underlying discrete response measures and disentangle the explicit process operating in implicit sequence learning.

This protocol describes a modified serial reaction time (SRT) task used to study implicit motor sequence learning. Unlike the classic SRT task that ...