@article {1744,
	title = {Miniature motorized microdrive and commutator system for chronic neural recording in small animals.},
	journal = {Journal of Neuroscience Methods},
	volume = {112},
	year = {2001},
	month = {2001 Dec 15},
	pages = {83-94},
	abstract = {<p>The use of chronically implanted electrodes for neural recordings in small, freely behaving animals poses several unique technical challenges. Because of the need for an extremely lightweight apparatus, chronic recording technology has been limited to manually operated microdrives, despite the advantage of motorized manipulators for positioning electrodes. Here we describe a motorized, miniature chronically implantable microdrive for independently positioning three electrodes in the brain. The electrodes are controlled remotely, avoiding the need to disturb the animal during electrode positioning. The microdrive is approximately 6 mm in diameter, 17 mm high and weighs only 1.5 g, including the headstage preamplifier. Use of the motorized microdrive has produced a ten-fold increase in our data yield compared to those experiments done using a manually operated drive. In addition, we are able to record from multiple single neurons in the behaving animal with signal quality comparable to that seen in a head-fixed anesthetized animal. We also describe a motorized commutator that actively tracks animal rotation based on a measurement of torque in the tether.</p>
},
	keywords = {Action Potentials, Animal, Animals, Behavior, Brain, Electrodes, Electronics, Electrophysiology, Feedback, Implanted, Male, Medical, Neurons, Neurophysiology, Songbirds, Torque},
	issn = {0165-0270},
	author = {Fee, M S and Leonardo, A}
}
@article {1745,
	title = {Decrystallization of adult birdsong by perturbation of auditory feedback.},
	journal = {Nature},
	volume = {399},
	year = {1999},
	month = {1999 Jun 3},
	pages = {466-70},
	abstract = {<p>Young birds learn to sing by using auditory feedback to compare their own vocalizations to a memorized or innate song pattern; if they are deafened as juveniles, they will not develop normal songs. The completion of song development is called crystallization. After this stage, song shows little variation in its temporal or spectral properties. However, the mechanisms underlying this stability are largely unknown. Here we present evidence that auditory feedback is actively used in adulthood to maintain the stability of song structure. We found that perturbing auditory feedback during singing in adult zebra finches caused their song to deteriorate slowly. This {\textquoteright}decrystallization{\textquoteright} consisted of a marked loss of the spectral and temporal stereotypy seen in crystallized song, including stuttering, creation, deletion and distortion of song syllables. After normal feedback was restored, these deviations gradually disappeared and the original song was recovered. Thus, adult birds that do not learn new songs nevertheless retain a significant amount of plasticity in the brain.</p>
},
	keywords = {Aging, Animals, Auditory Perception, Feedback, Learning, Male, Songbirds},
	issn = {0028-0836},
	doi = {10.1038/20933},
	author = {Leonardo, A and Konishi, M}
}
