Name: behavioral assessment of visual function via optomotor response and cognitive function via y-maze in diabetic rats
Uploaded: 2020-10-23T15:00:00
Description: Watch this Scientific Journal Video about Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats at JoVE.com

This work was supported by the Department of Veterans Affairs Rehab R&#38;D Service Career Development Awards (CDA-1, RX002111; CDA-2; RX002928) to RSA and (CDA-2, RX002342) to AJF and the National Institutes of Health (NIH-NICHD F31 HD097918 to DACT and NIH-NIEHS T32 ES012870 to DACT) and NEI Core Grant P30EY006360.

All procedures were approved by the Atlanta Veterans Affairs Institutional Animal Care and Use Committee and conformed to the National Institutes of Health guide for the care and use of laboratory animals (NIH Publications, 8th edition, updated 2011).
1. The optomotor response (OMR)
<ol>
	<li>Set up the OMR apparatus (details on apparatus and software in Table of Materials)
	<ol>
		<li>Choose the appropriate-sized platform for the rodent: mouse, rat, or large/impa...

<ol>
	<li>. International Diabetes Federation Diabetes Atlas, 9th edn Available from: <a target="_blank" href="https://diabetesatlas.org/upload/resources/material/20200302_133351_IDFATLAfinal-web.pdf">https://diabetesatlas.org/upload/resources/material/20200302_133351_IDFATLAfinal-web.pdf</a> (2019)</li><li>Wang, W., Lo, A. C. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diabetic+retinopathy:+pathophysiology+and+treatments.">Diabetic retinopathy: pathophysiology and treatments.</a> International Journal of Molecular Sciences. 19 (6), (2018).</li><li>Akpek, E. K., Smith, 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=Overview+of+age-related+ocular+conditions.">Overview of age-related ocular conditions.</a> The American Journal of Managed Care. 19 (5), 67-75 (2013).</li><li>Urano, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wolfram+syndrome:+diagnosis,+management,+and+treatment.">Wolfram syndrome: diagnosis, management, and treatment.</a> Current Diabetes Reports. 16 (1), 6 (2016).</li><li>Adeva-Andany, M. M., Funcasta-Calder&#243;n, R., Fern&#225;ndez-Fern&#225;ndez, C., Ameneiros-Rodr&#237;guez, E., Dom&#237;nguez-Montero, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subclinical+vascular+disease+in+patients+with+diabetes+is+associated+with+insulin+resistance.">Subclinical vascular disease in patients with diabetes is associated with insulin resistance.</a> Diabetes &amp; Metabolic Syndrome: Clinical Research &amp; Reviews. 13 (3), 2198-2206 (2019).</li><li>Chin, J. A., Sumpio, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diabetes+mellitus+and+peripheral+vascular+disease:+diagnosis+and+management.">Diabetes mellitus and peripheral vascular disease: diagnosis and management.</a> Clinics in Podiatric Medicine and Surgery. 31 (1), 11-26 (2014).</li><li>Barber, A. J., Gardner, T. W., Abcouwer, S. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+significance+of+vascular+and+neural+apoptosis+to+the+pathology+of+diabetic+retinopathy.">The significance of vascular and neural apoptosis to the pathology of diabetic retinopathy.</a> Investigative Ophthalmology &amp; Visual Science. 52 (2), 1156-1163 (2011).</li><li>Pardue, M. T., Allen, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroprotective+strategies+for+retinal+disease.">Neuroprotective strategies for retinal disease.</a> Progress in Retinal and Eye Research. 65, 50-76 (2018).</li><li>Aung, M. H., Kim, M. K., Olson, D. E., Thule, P. M., Pardue, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+visual+deficits+in+streptozotocin-induced+diabetic+long+evans+rats.">Early visual deficits in streptozotocin-induced diabetic long evans rats.</a> Investigative Ophthalmology &amp; Visual Science. 54 (2), 1370-1377 (2013).</li><li>Antonetti, D. 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=Diabetic+retinopathy:+seeing+beyond+glucose-induced+microvascular+disease.">Diabetic retinopathy: seeing beyond glucose-induced microvascular disease.</a> Diabetes. 55 (9), 2401-2411 (2006).</li><li>Logroscino, G., Kang, J. H., Grodstein, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prospective+study+of+type+2+diabetes+and+cognitive+decline+in+women+aged+70-81+years.">Prospective study of type 2 diabetes and cognitive decline in women aged 70-81 years.</a> BMJ. 328 (7439), 548 (2004).</li><li>London, A., Benhar, I., Schwartz, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+retina+as+a+window+to+the+brain-from+eye+research+to+CNS+disorders.">The retina as a window to the brain-from eye research to CNS disorders.</a> Nature Reviews Neurology. 9 (1), 44-53 (2013).</li><li>Archibald, N. K., Clarke, M. P., Mosimann, U. P., Burn, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+retina+in+Parkinson's+disease.">The retina in Parkinson's disease.</a> Brain. 132 (5), 1128-1145 (2009).</li><li>Sakai, R. E., Feller, D. J., Galetta, K. M., Galetta, S. L., Balcer, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vision+in+multiple+sclerosis:+the+story,+structure-function+correlations,+and+models+for+neuroprotection.">Vision in multiple sclerosis: the story, structure-function correlations, and models for neuroprotection.</a> Journal of Neuroophthalmology. 31 (4), 362-373 (2011).</li><li>Wong, T. Y., 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=Retinal+microvascular+abnormalities+and+incident+stroke:+the+Atherosclerosis+Risk+in+Communities+Study.">Retinal microvascular abnormalities and incident stroke: the Atherosclerosis Risk in Communities Study.</a> The Lancet. 358 (9288), 1134-1140 (2001).</li><li>Marqui&#233;, 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=Association+between+retinal+thickness+and+&#946;-amyloid+brain+accumulation+in+individuals+with+subjective+cognitive+decline:+Fundaci&#243;+ACE+Healthy+Brain+Initiative.">Association between retinal thickness and &#946;-amyloid brain accumulation in individuals with subjective cognitive decline: Fundaci&#243; ACE Healthy Brain Initiative.</a> Alzheimer's Research &amp; Therapy. 12 (1), 37 (2020).</li><li>Thomas, B. B., Seiler, M. J., Sadda, S. R., Coffey, P. J., Aramant, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optokinetic+test+to+evaluate+visual+acuity+of+each+eye+independently.">Optokinetic test to evaluate visual acuity of each eye independently.</a> Journal of Neuroscience Methods. 138 (1-2), 7-13 (2004).</li><li>Prusky, G. T., Alam, N. M., Beekman, S., Douglas, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+quantification+of+adult+and+developing+mouse+spatial+vision+using+a+virtual+optomotor+system.">Rapid quantification of adult and developing mouse spatial vision using a virtual optomotor system.</a> Investigative Ophthalmology &amp; Vision Science. 45 (12), 4611-4616 (2004).</li><li>Maurice, 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=Behavioral+evidence+for+a+modulating+role+of+&#963;+ligands+in+memory+processes.+I.+Attenuation+of+dizocilpine+(MK-801)-induced+amnesia.">Behavioral evidence for a modulating role of &#963; ligands in memory processes. I. Attenuation of dizocilpine (MK-801)-induced amnesia.</a> Brain Research. 647 (1), 44-56 (1994).</li><li>Douglas, R. 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=Independent+visual+threshold+measurements+in+the+two+eyes+of+freely+moving+rats+and+mice+using+a+virtual-reality+optokinetic+system.">Independent visual threshold measurements in the two eyes of freely moving rats and mice using a virtual-reality optokinetic system.</a> Visual Neuroscience. 22 (5), 677-684 (2005).</li><li>Feola, A. J., 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=Menopause+exacerbates+visual+dysfunction+in+experimental+glaucoma.">Menopause exacerbates visual dysfunction in experimental glaucoma.</a> Experimental Eye Research. 186, 107706 (2019).</li><li>Allen, R. S., 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=TrkB+signalling+pathway+mediates+the+protective+effects+of+exercise+in+the+diabetic+rat+retina.">TrkB signalling pathway mediates the protective effects of exercise in the diabetic rat retina.</a> European Journal of Neuroscience. 47 (10), 1254-1265 (2018).</li><li>Allen, R. S., 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=Retinal+deficits+precede+cognitive+and+motor+deficits+in+a+rat+model+of+type+II+diabetes.">Retinal deficits precede cognitive and motor deficits in a rat model of type II diabetes.</a> Investigative Ophthalmology &amp; Visual Science. 60 (1), 123-133 (2019).</li><li>Prusky, G. T., Harker, K. T., Douglas, R. M., 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=Variation+in+visual+acuity+within+pigmented,+and+between+pigmented+and+albino+rat+strains.">Variation in visual acuity within pigmented, and between pigmented and albino rat strains.</a> Behavioural Brain Research. 136 (2), 339-348 (2002).</li><li>Hwang, C. K., 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=Circadian+rhythm+of+contrast+sensitivity+is+regulated+by+a+dopamine-neuronal+PAS-domain+protein+2-adenylyl+cyclase+1+signaling+pathway+in+retinal+ganglion+cells.">Circadian rhythm of contrast sensitivity is regulated by a dopamine-neuronal PAS-domain protein 2-adenylyl cyclase 1 signaling pathway in retinal ganglion cells.</a> Journal of Neuroscience. 33 (38), 14989-14997 (2013).</li><li>Mui, A. 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=Daily+visual+stimulation+in+the+critical+period+enhances+multiple+aspects+of+vision+through+BDNF-mediated+pathways+in+the+mouse+retina.">Daily visual stimulation in the critical period enhances multiple aspects of vision through BDNF-mediated pathways in the mouse retina.</a> PLoS One. 13 (2), 0192435 (2018).</li><li>Feola, A. J., 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=Menopause+exacerbates+visual+dysfunction+in+experimental+glaucoma.">Menopause exacerbates visual dysfunction in experimental glaucoma.</a> Experimental Eye Research. 186, 107706 (2019).</li><li>Allen, R. S., 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=Long-term+functional+and+structural+consequences+of+primary+blast+overpressure+to+the+eye.">Long-term functional and structural consequences of primary blast overpressure to the eye.</a> Journal of Neurotrauma. 35 (17), 2104-2116 (2018).</li><li>Maaswinkel, H., Li, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatio-temporal+frequency+characteristics+of+the+optomotor+response+in+zebrafish.">Spatio-temporal frequency characteristics of the optomotor response in zebrafish.</a> Vision Research. 43 (1), 21-30 (2003).</li><li>Benkner, B., Mutter, M., Ecke, G., M&#252;nch, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterizing+visual+performance+in+mice:+an+objective+and+automated+system+based+on+the+optokinetic+reflex.">Characterizing visual performance in mice: an objective and automated system based on the optokinetic reflex.</a> Behavioral Neuroscience. 127 (5), 788-796 (2013).</li><li>Lehmann, K., Schmidt, K. F., L&#246;wel, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vision+and+visual+plasticity+in+ageing+mice.">Vision and visual plasticity in ageing mice.</a> Restorative Neurology and Neuroscience. 30, 161-178 (2012).</li><li>Leinonen, H., Tanila, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vision+in+laboratory+rodents-tools+to+measure+it+and+implications+for+behavioral+research.">Vision in laboratory rodents-tools to measure it and implications for behavioral research.</a> Behavioral Brain Research. 352, 172-182 (2018).</li><li>Spielmann, M., Schr&#246;ger, E., Kotz, S. A., Pechmann, T., Bendixen, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+a+staircase+procedure+for+the+objective+measurement+of+auditory+stream+integration+and+segregation+thresholds.">Using a staircase procedure for the objective measurement of auditory stream integration and segregation thresholds.</a> Frontiers in Psychology. 4, 534 (2013).</li><li>Shi, C., 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=Optimization+of+optomotor+response-based+visual+function+assessment+in+mice.">Optimization of optomotor response-based visual function assessment in mice.</a> Scientific Reports. 8 (1), 9708 (2018).</li><li>You, M., Yamane, T., Tomita, H., Sugano, E., Akashi, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+rat+head+gaze+determination+system+based+on+optomotor+responses.">A novel rat head gaze determination system based on optomotor responses.</a> PLoS One. 12 (4), 0176633 (2017).</li><li>Whyte, A. J., 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=Reward-related+expectations+trigger+dendritic+spine+plasticity+in+the+mouse+ventrolateral+orbitofrontal+cortex.">Reward-related expectations trigger dendritic spine plasticity in the mouse ventrolateral orbitofrontal cortex.</a> The Journal of Neuroscience. 39 (23), 4595-4605 (2019).</li></ol>

The OMR and the Y-maze allow for the non-invasive assessment of visual function and cognitive function deficits in rodents over time. In this protocol, the OMR and the Y-maze were demonstrated to track visual and cognitive deficits in rodent models of diabetes.
Critical steps in the protocol
The OMR
Some important points to consider when performing the OMR to assess visual function are the testing parameters used, experim...

An erratum was issued for:&#160;<a href="https://www.jove.com/t/61806">Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats</a>. The author list was updated.
The author list was updated from:
Kaavya Gudapati*1,2, Anayesha Singh*1,3, Danielle Clarkson-Townsend1,4, Andrew J. Feola1,2, Rachael S. Allen1,2 
1Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 
2Department of Biomedical Engineering, Georgia Institute of Technology, 
3Department of Neuroscience, Emory University, 
4Gangarosa Department of Environmental Health, Emory University 
* These authors contributed equally
to:
Kaavya Gudapati*1,2, Anayesha Singh*1,3, Danielle Clarkson-Townsend1,4, Stephen Q. Phillips1, Amber Douglass1, Andrew J. Feola1,2, Rachael S. Allen1,2 
1Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 
2Department of Biomedical Engineering, Georgia Institute of Technology, 
3Department of Neuroscience, Emory University, 
4Gangarosa Department of Environmental Health, Emory University 
* These authors contributed equally

An erratum was issued for:&#160;<a href="https://www.jove.com/t/61806">Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats</a>. The author list was updated.

Erratum: Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats

Over 463 million people live with diabetes, making it one of the largest global disease epidemics1. One of the serious complications that arises from diabetes is diabetic retinopathy (DR), a leading cause of blindness for working-age American adults2. In the next 30 years, the percentage of the population at risk for DR is projected to double, so it is crucial to find new ways of diagnosing DR in its earlier stages to prevent and mitigate DR development3. DR has conventionally been thought to be a vascular disease4,5,6. However, now with evidence of neuronal dysfunction and apoptosis in the retina that precedes vascular pathology, DR is defined to have neuronal and vascular components4,5,6,7,8,9. One way to diagnose DR would be to examine neural abnormalities in the retina, a tissue that may be more vulnerable to oxidative stress and metabolic strain from diabetes than other neural tissue10.
Declines in cognitive and motor function also occur with diabetes and are often correlated with retinal changes. Older individuals with Type II diabetes portray worse baseline cognitive performance and show more exacerbated cognitive decline than control participants11. Additionally, the retina has been established as an extension of the central nervous system and pathologies can manifest in the retina12. Clinically, the relationship between retina and brain has been studied in the context of Alzheimer&#8217;s and other diseases but is not commonly explored with diabetes12,13,14,15,16. Changes in the brain and retina during the progression of diabetes can be explored using animal models, including the STZ rat (a model of Type I diabetes in which the toxin, streptozotocin or STZ, is used to damage pancreatic beta cells) and the Goto-Kakizaki rat (a polygenic model of Type II diabetes in which animals develop hyperglycemia spontaneously at around 3 weeks of age). In this protocol, a description for the Y-maze and the optomotor response to assess cognitive and visual changes in diabetic rodents, respectively, is provided. The optomotor response (OMR) assesses spatial frequency (similar to visual acuity) and contrast sensitivity by monitoring characteristic reflexive head tracking movements to gauge visual thresholds for each eye17. Spatial frequency refers to the thickness or fineness of the bars, and contrast sensitivity refers to how much contrast there is between the bars and the background (Figure 1E). Meanwhile, the Y-maze tests short-term spatial memory and exploratory function, observed through spontaneous alternations and entries through the arms of the maze.
Both tests can be performed in awake, non-anesthetized animals and have the advantage of capitalizing on innate responses of the animals, meaning that they do not require training. Both are relatively sensitive, in that they can be used to detect deficits early in the progression of diabetes in rodents, and reliable, in that they produce results that correlate with other visual, retinal, or behavioral tests. Additionally, using the OMR and the Y-maze in conjunction with tests such as electroretinogram and optical coherence tomography scans can provide information on when retinal, structural, and cognitive changes develop relative to each other in disease models. These investigations could be useful in identifying neural degenerations that occur due to diabetes. Ultimately, this could lead to new diagnostic methods that effectively identify DR in early stages of progression.
The OMR and the Y-maze systems used to develop this protocol are described in the Table of Materials. Previous research on the OMR, by Prusky et al.18, and the Y-maze, by Maurice et al.19, was used as the starting point to develop this protocol.

<table>
	<tbody>
		<tr>
			<td>OptoMotry HD</td>
			<td>CerebralMechanics Inc.</td>
			<td></td>
			<td>OMR apparatus &#38; software</td>
		</tr>
		<tr>
			<td>Timer</td>
			<td>Thomas Scientific</td>
			<td>810029AR</td>
			<td></td>
		</tr>
		<tr>
			<td>Y-Maze apparatus</td>
			<td>San Diego Instruments</td>
			<td>7001-043</td>
			<td>Available specifically for rats</td>
		</tr>
	</tbody>
</table>

behavioral assessment of visual function via optomotor response and cognitive function via y-maze in diabetic rats

The optomotor response and the Y-maze are behavioral tests useful for assessing visual and cognitive function, respectively. The optomotor response is a valuable tool to track changes in spatial frequency (SF) and contrast sensitivity (CS) thresholds over time in a number of retinal disease models, including diabetic retinopathy. Similarly, the Y-maze can be used to monitor spatial cognition (as measured by spontaneous alternation) and exploratory behavior (as measured by a number of entries) in a number of disease models that affect the central nervous system. Advantages of the optomotor response and the Y-maze include sensitivity, speed of testing, the use of innate responses (training is not needed), and the ability to be performed on awake (non-anesthetized) animals. Here, protocols are described for both the optomotor response and the Y-maze and examples of their use shown in models of Type I and Type II diabetes. Methods include preparation of rodents and equipment, performance of the optomotor response and the Y-maze, and post-test data analysis.

The OMR is considered successful if spatial frequency and contrast sensitivity thresholds can be obtained from a rodent. Here, the use of the OMR to assess spatial frequency is illustrated in na&#239;ve control Brown-Norway and Long-Evans rats, both young (3&#8211;6 months) and aged (9&#8211;12 months). Brown-Norway rats typically show a higher baseline spatial frequency than Long-Evans rats. Additionally, an aging effect on spatial frequency was observed in the Long-Evans rats (Figure 3A). ...

Watch this Scientific Journal Video about Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats at JoVE.com

Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats

Neural degeneration in both eyes and brain as a result of diabetes can be observed through behavioral tests carried out on rodents. The Y-maze, a measure of spatial cognition, and the optomotor response, a measure of visual function, both provide insight into potential diagnoses and treatments.

The optomotor response and the Y-maze are behavioral tests useful for assessing visual and cognitive function, respectively. The optomotor response is a ...

The optomotor response and the Y-maze are behavioral tests that are useful in measuring visual function and cognitive function respectively in a wide variety of disease models. Advantages of these tests include sensitivity, speed of testing, the use of innate responses such that training isn't needed, and the ability to perform the tests on awake non-anesthetized animals. OMR and Y-maze can be used along with other tests to identify temporal appearance of retinal and brain dysfunction in diseases like diabetes with the goal being earlier diagnosis.Demonstrating the Y-maze will be Stephen Phillips, a research technician from my laboratory. Demonstrating the optomotor response or OMR procedure will be Amber Douglass, a research technician in the Allen and Viola Labs. To set up the OMR apparatus, first select an appropriate-sized platform for the experimental animal species to be used and open the OMR software.Zoom in or out with the video camera as needed so that the platform and its surroundings are visible and click the asterisk and rotating stripes icons so that both the green asterisk and green rotating stripes disappear from the live feed. Click the compass icon so that a green circle and two perpendicular lines appear and stretch the green circle so that it aligns perfectly with the black circle on the platform. When the OMR is completely aligned, re-click the compass, asterisk, and rotating stripes icons.Note that the green stripes will rotate in the same direction as the stripes in the drum. Under the testing tab, click the psychophysics tab. To measure spatial frequency, under threshold, select frequency.Under testing, click presets and select the default settings for the experimental animal being used. Click the blanking tab and check the blank on tracking box to pause the stripes and blank out the computer screens in the drum whenever the mouse is right-clicked. Then click the results tab to open the window in which the results of the test will be displayed.To assess spatial frequency, place the rodent onto the circular platform in the center of a virtual reality chamber comprised of four computer monitors showing vertical sine wave gradings circling the chamber at a velocity of 12 degrees per second. The video camera positioned at the top of the chamber should project the rodent's behavior live on the computer monitor. Look for the presence or absence of reflexive actions by the rodent's head as the gradings move in a clockwise or counterclockwise direction.Make sure that illustrated bars are visible in the program as they will show the direction of the grading movement. Watch for the rodent's head to move in the same direction as the gradings. When there is a smooth pursuit, not erratic bursts of head motion, count this movement as tracking.Click on yes or no as appropriate. Spatial frequency will start at 0.042 cycle or degree and adjust with each yes and no click to become easier or more difficult. As the rodent is tested, make sure to keep the asterisk positioned over the rodent's head and watch for the system to say done when the rodent's spatial frequency threshold is reached.Note that the yes and no buttons will no longer be able to be clicked. Then open the results tab to view the spatial frequency for the left, right, and combined eyes. To measure contrast sensitivity, in the testing and psychophysics tabs, select contrast single.Open the stimulus and gradings tabs and enter the appropriate value into the spatial frequency box to start gradings with the spatial frequency constant at the peak of the contrast sensitivity curve. Begin the contrast at 100%and look for the same reflexive head movements as observed during spatial frequency testing. Note that the contrast will decrease as the testing progresses until the rodent no longer has reflexive head movements in response to the stimulus.When the contrast sensitivity threshold has been reached, open the results tab to view the contrast sensitivity values for the left, right, and combined eyes. To conduct a Y-maze analysis, first label the initial arm of the Y-maze as B and the other two arms as A and C and place the rodent in the B arm near the center of the maze. Immediately start the timer and allow the rodent to explore the Y-maze for eight minutes.Sit several feet away from the maze, keeping it in sight and avoiding making any noise while taking recordings and noting any observations. Record the starting location as B.Each time the rodent makes an entry into a new arm, record the new location of the rodent. If the rodent remains in the same spot for more than 60 seconds and does not appear to show exploratory behavior, move the rodent toward the center of the Y-maze and continue the trial.After at the end of each trial, remove any feces and clean the maze with sanitizing solution. Calculate the exploratory behavior as the total number of entries made over the eight minutes of the trial. The spatial cognition is calculated as the number of successful alternations divided by the total number of entries.Here, the use of the OMR to assess spatial frequency is illustrated in naive controlled Brown Norway and Long-Evans rats. Brown Norway rats typically show a higher baseline spatial frequency than Long-Evans rats. Additionally, an aging effect on spatial frequency is observed in the Long-Evans rats.Using the OMR to assess contrast sensitivity reveals significant deficits in contrast sensitivity in type one diabetic rats. Exercise treatment reduces these deficits, demonstrating that the OMR is useful both for detecting and tracking retinal deficits over time with and without intervention. Using a Y-maze to assess cognitive function and exploratory behavior in a type two model of diabetes shows significant deficits in spatial cognition as measured by spontaneous alternation and exploratory behavior as measured by number of entries in Goto-Kakizaki rats compared with Wistar control animals beginning at seven weeks of age.Learning how to identify a tracking head movement in step 3.4 is the most difficult part of OMR. Learning what a smooth pursuit movement looks like is critical. The OMR and Y-maze paved the way for IM brain researchers to quickly and reliably measure visual and cognitive function without training and with minimal stress to the animals.

behavioral-assessment-visual-function-via-optomotor-response

Research

JoVE Journal

Behavior

Assessment of Sensorimotor Function in Mouse Models of Parkinson's Disease

Sensitive and reliable behavioral outcome measures are essential to the evaluation of potential therapeutic treatments in preclinical trials for many neurodegenerative diseases. In Parkinson's disease, sensorimotor tests sensitive to varying degrees of nigrostriatal dysfunction are fundamental for testing the efficacy of potential therapeutics. Reliable and quite elegant sensorimotor measures exist for rats, however many of these tests measure sensorimotor asymmetry within the rat and are not entirely suitable for the newer genetic mouse models of PD. We have put together a battery of sensorimotor tests inspired by the sensitive tests in rats and adapted for mice. The test battery highlighted in this study is chosen for a) its sensitivity in a wide variety of mouse models of PD, b) its ease in implementing into a study, and c) its low expense. These tests have proven useful in characterizing novel genetic mouse models of PD as well as in testing potential disease-modifying therapies.

Assessment of Sensorimotor Function in Mouse Models of Parkinson&#039;s Disease

In Parkinson's disease and movement disorders in general, sensitive and reliable behavioral assays are essential for testing novel potential therapeutics. Here, we describe a manageable battery of sensorimotor tests for mice that are sensitive to varying degrees of injury to the nigrostriatal system and useful for preclinical studies.

Sensitive and  reliable behavioral outcome measures are essential to the evaluation of  potential therapeutic treatments in preclinical trials for many  ...

Irrelevant Stimuli and Action Control: Analyzing the Influence of Ignored Stimuli via the Distractor-Response Binding Paradigm

Selection tasks in which simple stimuli (e.g. letters) are presented and a target stimulus has to be selected against one or more distractor stimuli are frequently used in the research on human action control. One important question in these settings is how distractor stimuli, competing with the target stimulus for a response, influence actions. The distractor-response binding paradigm can be used to investigate this influence. It is particular useful to separately analyze response retrieval and distractor inhibition effects. Computer-based experiments are used to collect the data (reaction times and error rates). In a number of sequentially presented pairs of stimulus arrays (prime-probe design), participants respond to targets while ignoring distractor stimuli. Importantly, the factors response relation in the arrays of each pair (repetition vs. change) and distractor relation (repetition vs. change) are varied orthogonally. The repetition of the same distractor then has a different effect depending on response relation (repetition vs. change) between arrays. This result pattern can be explained by response retrieval due to distractor repetition. In addition, distractor inhibition effects are indicated by a general advantage due to distractor repetition. The described paradigm has proven useful to determine relevant parameters for response retrieval effects on human action.

The distractor-response binding paradigm is described. It can be used to shed light on the influence irrelevant stimuli, competing with targets for a response, can have on human action. Both response retrieval effects and distractor inhibition effects can be analyzed within the paradigm.

Selection tasks in which simple stimuli (e.g. letters) are presented and a target stimulus has to be selected against one or more distractor stimuli are ...

A Procedure to Observe Context-induced Renewal of Pavlovian-conditioned Alcohol-seeking Behavior in Rats

Environmental contexts in which drugs of abuse are consumed can trigger craving, a subjective Pavlovian-conditioned response that can facilitate drug-seeking behavior and prompt relapse in abstinent drug users. We have developed a procedure to study the behavioral and neural processes that mediate the impact of context on alcohol-seeking behavior in rats. Following acclimation to the taste and pharmacological effects of 15% ethanol in the home cage, male Long-Evans rats receive Pavlovian discrimination training (PDT) in conditioning chambers. In each daily (Mon-Fri) PDT session, 16 trials each of two different 10 sec auditory conditioned stimuli occur. During one stimulus, the CS+, 0.2 ml of 15% ethanol is delivered into a fluid port for oral consumption. The second stimulus, the CS-, is not paired with ethanol. Across sessions, entries into the fluid port during the CS+ increase, whereas entries during the CS- stabilize at a lower level, indicating that a predictive association between the CS+ and ethanol is acquired. During PDT each chamber is equipped with a specific configuration of visual, olfactory and tactile contextual stimuli. Following PDT, extinction training is conducted in the same chamber that is now equipped with a different configuration of contextual stimuli. The CS+ and CS- are presented as before, but ethanol is withheld, which causes a gradual decline in port entries during the CS+. At test, rats are placed back into the PDT context and presented with the CS+ and CS- as before, but without ethanol. This manipulation triggers a robust and selective increase in the number of port entries made during the alcohol predictive CS+, with no change in responding during the CS-. This effect, referred to as context-induced renewal, illustrates the powerful capacity of contexts associated with alcohol consumption to stimulate alcohol-seeking behavior in response to Pavlovian alcohol cues.

A procedure to study the capacity of an alcohol associated environmental context to trigger the renewal of alcohol-seeking behavior in rats is described.

Environmental contexts in which drugs of abuse are consumed can trigger craving, a subjective Pavlovian-conditioned response that can facilitate ...

The Knob Supination Task: A Semi-automated Method for Assessing Forelimb Function in Rats

Tasks that accurately measure dexterity in animal models are critical to understand hand function. Current rat behavioral tasks that measure dexterity largely use video analysis of reaching or food manipulation. While these tasks are easy to implement and are robust across disease models, they are subjective and laborious for the experimenter. Automating traditional tasks or creating new automated tasks can make the tasks more efficient, objective, and quantitative. Since rats are less dexterous than primates, central nervous system (CNS) injury produces more subtle deficits in dexterity, however, supination is highly affected in rodents and crucial to hand function in primates. Therefore, we designed a semi-automated task that measures forelimb supination in rats. Rats are trained to reach and grasp a knob-shaped manipulandum and turn the manipulandum in supination to receive a reward. Rats can acquire the skill within 20 &plusmn; 5 days. While the early part of training is highly supervised, much of the training is done without direct supervision. The task reliably and reproducibly captures subtle deficits after injury and shows functional recovery that accurately reflects clinical recovery curves. Analysis of data is performed by specialized software through a graphical user interface that is designed to be intuitive. We also give solutions to common problems encountered during training, and show that minor corrections to behavior early in training produce reliable acquisition of supination. Thus, the knob supination task provides efficient and quantitative evaluation of a critical movement for dexterity in rats.

This manuscript describes a semi-automated task that quantifies supination in rats. Rats reach, grasp, and supinate a spherical manipulandum. The rat is rewarded with a pellet if the turn angle exceeds a criterion set by the user. This task increases throughput, sensitivity to injury, and objectivity compared to traditional tasks.

Tasks that accurately measure dexterity in animal models are critical to understand hand function. Current rat behavioral tasks that measure dexterity ...

Simultaneous Recordings of Cortical Local Field Potentials and Electrocorticograms in Response to Nociceptive Laser Stimuli from Freely Moving Rats

Electrocortical responses, elicited by laser heat pulses that selectively activate nociceptive free nerve endings, are widely used in many animal and human studies to investigate the cortical processing of nociceptive information. These laser-evoked brain potentials (LEPs) consist of several transient responses that are time-locked to the onset of laser stimuli. However, the functional properties of the LEP responses are still largely unknown, due to the lack of a sampling technique that can simultaneously record neural activities at the surface of the cortex (i.e., electrocorticogram [ECoG] and scalp electroencephalogram [scalp EEG]) and inside the brain (i.e., local field potential [LFP]). To address this issue, we present here an animal protocol using freely moving rats. This protocol is composed of three main procedures: (1) animal preparation and surgical procedures, (2) a simultaneous recording of ECoG and LFP in response to nociceptive laser stimuli, and (3) data analysis and feature extraction. Specifically, with the help of a 3D-printed protective shell, both ECoG and LFP electrodes implanted on the rat&#39;s skull were securely held together. During data collection, laser pulses were delivered on the rat&#39;s forepaws through gaps in the bottom of the chamber when the animal was in spontaneous stillness. Ongoing white noise was played to avoid the activation of the auditory system by the laser-generated ultrasounds. As a consequence, only nociceptive responses were selectively recorded. Using the standard analytical procedures (e.g., band-pass filtering, epoch extraction, and baseline correction) to extract stimulus-related brain responses, we obtained results showing that LEPs with a high signal-to-noise ratio were simultaneously recorded from ECoG and LFP electrodes. This methodology makes the simultaneous recording of ECoG and LFP activities possible, which provides a bridge of electrocortical signals at the mesoscopic and macroscopic levels, thereby facilitating the investigation of nociceptive information processing in the brain.

We developed a technique that simultaneously records both electrocorticography and local field potentials in response to nociceptive laser stimuli from freely moving rats. This technique helps establish a direct relationship of electrocortical signals at the mesoscopic and macroscopic levels, which facilitates the investigation of nociceptive information processing in the brain.

Electrocortical responses, elicited by laser heat pulses that selectively activate nociceptive free nerve endings, are widely used in many animal and ...

Supramaximal Intensity Hypoxic Exercise and Vascular Function Assessment in Mice

Exercise training is an important strategy for maintaining health and preventing many chronic diseases. It is the first line of treatment recommended by international guidelines for patients suffering from cardiovascular diseases, more specifically, lower extremity artery diseases, where the patients' walking capacity is considerably altered, affecting their quality of life. 
Traditionally, both low continuous exercise and interval training have been used. Recently, supramaximal training has also been shown to improve athletes' performances via vascular adaptations, amongst other mechanisms. The combination of this type of training with hypoxia could bring an additional and/or synergic effect, which could be of interest for certain pathologies. Here, we describe how to perform supramaximal intensity training sessions in hypoxia on healthy mice at 150% of their maximal speed, using a motorized treadmill and a hypoxic box. We also show how to dissect the mouse in order to retrieve organs of interest, particularly the pulmonary artery, the abdominal aorta, and the iliac artery. Finally, we show how to perform ex vivo vascular function assessment on the retrieved vessels, using isometric tension studies.

High-intensity training in hypoxia is a protocol that has been proven to induce vascular adaptations potentially beneficial in some patients and to improve athletes&#39; repeated sprint ability. Here, we test the feasibility of training mice using that protocol and identify those vascular adaptations using ex vivo vascular function assessment.

Exercise training is an important strategy for maintaining health and preventing many chronic diseases. It is the first line of treatment recommended by ...

Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity

This experimental protocol was designed to investigate whether visual attention is obligatorily deployed at the endpoint of saccades. To this end, we recorded the eye position of human participants engaged in a saccade task via eye tracking and assessed visual orientation discrimination performance at various locations during saccade preparation. Importantly, instead of using a single saccade target paradigm for which the saccade endpoint typically coincides roughly with the target, this protocol comprised the presentation of two nearby saccade targets, leading to a distinct spatial dissociation between target locations and saccade endpoint on a substantial number of trials. The paradigm allowed us to compare presaccadic visual discrimination performance at the endpoint of accurate saccades (landing at one of the saccade targets) and of averaging saccades (landing at an intermediate location in between the two targets). We observed a selective enhancement of visual sensitivity at the endpoint of accurate saccades but not at the endpoint of averaging saccades. Rather, before the execution of averaging saccades, visual sensitivity was equally enhanced at both targets, suggesting that saccade averaging follows from unresolved attentional selection among the saccade targets. These results argue against a mandatory coupling between visual attention and saccade programming based on a direct measure of presaccadic visual sensitivity rather than saccadic reaction times, which have been used in other protocols to draw similar conclusions. While our protocol provides a useful framework to investigate the relationship between visual attention and saccadic eye movements at the behavioral level, it can also be combined with electrophysiological measures to extend insights at the neuronal level.

This experimental protocol combined eye tracking and the assessment of presaccadic visual sensitivity in a dual task paradigm, consisting of a free choice saccade task and a visual discrimination task, to investigate the deployment of visual spatial attention before both, accurate and averaging saccades.

This experimental protocol was designed to investigate whether visual attention is obligatorily deployed at the endpoint of saccades. To this end, we ...

Integrating Visual Psychophysical Assays within a Y-Maze to Isolate the Role that Visual Features Play in Navigational Decisions

Collective animal behavior arises from individual motivations and social interactions that are critical for individual fitness. Fish have long inspired investigations into collective motion, specifically, their ability to integrate environmental and social information across ecological contexts. This demonstration illustrates techniques used for quantifying behavioral responses of fish, in this case, Golden Shiner (Notemigonus crysoleucas), to visual stimuli using computer visualization and digital image analysis. Recent advancements in computer visualization allow for empirical testing in the lab where visual features can be controlled and finely manipulated to isolate the mechanisms of social interactions. The purpose of this method is to isolate visual features that can influence the directional decisions of the individual, whether solitary or with groups. This protocol provides specifics on the physical Y-maze domain, recording equipment, settings and calibrations of the projector and animation, experimental steps and data analyses. These techniques demonstrate that computer animation can elicit biologically-meaningful responses. Moreover, the techniques are easily adaptable to test alternative hypotheses, domains, and species for a broad range of experimental applications. The use of virtual stimuli allows for the reduction and replacement of the number of live animals required, and consequently reduces laboratory overhead.
This demonstration tests the hypothesis that small relative differences in the movement speeds (2 body lengths per second) of virtual conspecifics will improve the speed and accuracy with which shiners follow the directional cues provided by the virtual silhouettes. Results show that shiners directional decisions are significantly affected by increases in the speed of the visual cues, even in the presence of background noise (67% image coherency). In the absence of any motion cues, subjects chose their directions at random. The relationship between decision speed and cue speed was variable and increases in cue speed had a modestly disproportionate influence on directional accuracy.

Here, we present a protocol to demonstrate a behavioral assay that quantifies how alternative visual features, such as motion cues, influence directional decisions in fish. Representative data are presented on the speed and accuracy where Golden Shiner (Notemigonus crysoleucas) follow virtual fish movements.

Collective animal behavior arises from individual motivations and social interactions that are critical for individual fitness. Fish have long inspired ...

Dynamic Digital Biomarkers of Motor and Cognitive Function in Parkinson's Disease

As Parkinson&#8217;s disease (PD) is a heterogeneous disorder, personalized medicine is truly required to optimize care. In their current form, standard scores from paper and pencil symptom- measures traditionally used to track disease progression are too coarse (discrete) to capture the granularity of the clinical phenomena under consideration, in the face of tremendous symptom diversity. For this reason, sensors, wearables, and mobile devices are increasingly incorporated into PD research and routine care. These digital measures, while more precise, yield data that are less standardized and interpretable than traditional measures, and consequently, the two types of data remain largely siloed. Both of these issues present barriers to the broad clinical application of the field&#8217;s most precise assessment tools. This protocol addresses both problems. Using traditional tasks to measure cognition and motor control, we test the participant, while co-registering biophysical signals unobtrusively using wearables. We then integrate the scores from traditional paper-and-pencil methods with the digital data that we continuously register. We offer a new standardized data type and unifying statistical platform that enables the dynamic tracking of change in the person&#8217;s stochastic signatures under different conditions that probe different functional levels of neuromotor control, ranging from voluntary to autonomic. The protocol and standardized statistical framework offer dynamic digital biomarkers of physical and cognitive function in PD that correspond to validated clinical scales, while significantly improving their precision.&#160;

Dynamic Digital Biomarkers of Motor and Cognitive Function in Parkinson&#039;s Disease

This protocol offers a digitization of portions of traditional clinical tasks commonly used to measure cognition and motor control in Parkinson&#8217;s disease. Clinical tasks are digitized while biophysical rhythms are co-registered from different functional levels of the nervous systems, ranging from voluntary, spontaneous, automatic to autonomic.

As Parkinson&#8217;s disease (PD) is a heterogeneous disorder, personalized medicine is truly required to optimize care. In their current form, standard ...

Nest Building Behavior as an Early Indicator of Behavioral Deficits in Mice

Nest building is an innate behavior in male and female rodents, even when raised in laboratory settings. As such, many researchers provide rodents synthetic and/or natural materials (such as twine, tissue, cotton, paper, and hay) as a gauge of their overall well-being and as an ancillary assessment to predict the possible decline in cognition. Typically, changes in nesting behaviors, such as failure to create a nest, indicate a change in health or welfare. In addition, nesting behavior is sensitive to many environmental and physiological challenges, as well as many genetic mutations underlying pathological disease states. The following protocol describes a nesting behavior paradigm that explores the usage of four types of nesting material. In addition, the protocol utilizes intraclass correlations to demonstrate that inter-rater reliability is higher when nests are constructed out of shredded paper compared to other common nesting materials such as cotton squares, paper twists, and soft cob bedding. The chosen methodology and statistical considerations (i.e., intraclass correlation) for this assay may be of interest for those conducting experiments assessing the quality of living of mice.&#160;

Here, we present a protocol to quantify nest building behavior in mice, which is known to be impaired in several neurological disorders and diseases. This protocol examines the utility of four materials and offers the opportunity to quantify the rater agreement in scoring, improving the validity and reliability of the assay.