@article {48275,
	title = {Optogenetics through windows on the brain in the nonhuman primate.},
	journal = {Journal of neurophysiology},
	volume = {110},
	year = {2013},
	month = {2013 Sep},
	pages = {1455-67},
	abstract = {<p>Optogenetics combines optics and genetics to control neuronal activity with cell-type specificity and millisecond temporal precision. Its use in model organisms such as rodents, Drosophila, and Caenorhabditis elegans is now well-established. However, application of this technology in nonhuman primates (NHPs) has been slow to develop. One key challenge has been the delivery of viruses and light to the brain through the thick dura mater of NHPs, which can only be penetrated with large-diameter devices that damage the brain. The opacity of the NHP dura prevents visualization of the underlying cortex, limiting the spatial precision of virus injections, electrophysiological recordings, and photostimulation. Here, we describe a new optogenetics approach in which the native dura is replaced with an optically transparent artificial dura. This artificial dura can be penetrated with fine glass micropipettes, enabling precisely targeted injections of virus into brain tissue with minimal damage to cortex. The expression of optogenetic agents can be monitored visually over time. Most critically, this optical window permits targeted, noninvasive photostimulation and concomitant measurements of neuronal activity via intrinsic signal imaging and electrophysiological recordings. We present results from both anesthetized-paralyzed (optical imaging) and awake-behaving NHPs (electrophysiology). The improvements over current methods made possible by the artificial dura should enable the widespread use of optogenetic tools in NHP research, a key step toward the development of therapies for neuropsychiatric and neurological diseases in humans.</p>
},
	keywords = {Animals, Brain, Dura Mater, Gene Transfer Techniques, Haplorhini, Neurosurgical Procedures, Optogenetics},
	issn = {1522-1598},
	doi = {10.1152/jn.00153.2013},
	author = {Ruiz, Octavio and Lustig, Brian R and Nassi, Jonathan J and Cetin, Ali and Reynolds, John H and Albright, Thomas D and Callaway, Edward M and Stoner, Gene R and Roe, Anna W}
}
@article {48276,
	title = {Voltage-sensitive dye imaging reveals shifting spatiotemporal spread of whisker-induced activity in rat barrel cortex.},
	journal = {Journal of neurophysiology},
	volume = {109},
	year = {2013},
	month = {2013 May},
	pages = {2382-92},
	abstract = {<p>In rats, navigating through an environment requires continuous information about objects near the head. Sensory information such as object location and surface texture are encoded by spike firing patterns of single neurons within rat barrel cortex. Although there are many studies using single-unit electrophysiology, much less is known regarding the spatiotemporal pattern of activity of populations of neurons in barrel cortex in response to whisker stimulation. To examine cortical response at the population level, we used voltage-sensitive dye (VSD) imaging to examine ensemble spatiotemporal dynamics of barrel cortex in response to stimulation of single or two adjacent whiskers in urethane-anesthetized rats. Single whisker stimulation produced a poststimulus fluorescence response peak within 12-16 ms in the barrel corresponding to the stimulated whisker (principal whisker). This fluorescence subsequently propagated throughout the barrel field, spreading anisotropically preferentially along a barrel row. After paired whisker stimulation, the VSD signal showed sublinear summation (less than the sum of 2 single whisker stimulations), consistent with previous electrophysiological and imaging studies. Surprisingly, we observed a spatial shift in the center of activation occurring over a 10- to 20-ms period with shift magnitudes of 1-2 barrels. This shift occurred predominantly in the posteromedial direction within the barrel field. Our data thus reveal previously unreported spatiotemporal patterns of barrel cortex activation. We suggest that this nontopographical shift is consistent with known functional and anatomic asymmetries in barrel cortex and that it may provide an important insight for understanding barrel field activation during whisking behavior.</p>
},
	keywords = {Action Potentials, Animals, Rats, Rats, Long-Evans, Sensory Receptor Cells, Somatosensory Cortex, Time Factors, Vibrissae, Voltage-Sensitive Dye Imaging},
	issn = {1522-1598},
	doi = {10.1152/jn.00430.2012},
	author = {Lustig, Brian R and Friedman, Robert M and Winberry, Jeremy E and Ebner, Ford F and Roe, Anna W}
}
