Synapses, Cells, and Circuits – Page 6 – UCLA Brain Research Institute (BRI)

20Jan

Scott Chandler, Ph.D.

Faculty Member

Selected Publications:

Hsiao, CF Wu, N Chandler, SH Voltage-dependent calcium currents in trigeminal motoneurons of early postnatal rats: modulation by 5-HT receptors Journal of neurophysiology. , 2005; 94(3): 2063-72.

Wu, N Enomoto, A Tanaka, S Hsiao, CF Nykamp, DQ Izhikevich, E Chandler, SH Persistent sodium currents in mesencephalic v neurons participate in burst generation and control of membrane excitability Journal of neurophysiology. , 2005; 93(5): 2710-22.

Tanaka, S Wu, N Hsaio, CF Turman, J Chandler, SH Development of inward rectification and control of membrane excitability in mesencephalic v neurons Journal of neurophysiology. , 2003; 89(3): 1288-98.

Wu, N Hsiao, CF Chandler, SH Membrane resonance and subthreshold membrane oscillations in mesencephalic V neurons: participants in burst generation The Journal of neuroscience : the official journal of the Society for Neuroscience. , 2001; 21(11): 3729-39.

Del Negro, C.A., Hsiao, C.F., and Chandler, S.H. Outward currents controlling bursting dynamics in guinea pig trigeminal motoneurons, J. Neurophysiology, 1999; 81: 1478-1485.

Del Negro, CA Hsiao, CF Chandler, SH Garfinkel, A Evidence for a novel bursting mechanism in rodent trigeminal neurons Biophysical journal. , 1998; 75(1): 174-82.

Hsiao, CF Del Negro, CA Trueblood, PR Chandler, SH Ionic basis for serotonin-induced bistable membrane properties in guinea pig trigeminal motoneurons Journal of neurophysiology. , 1998; 79(6): 2847-56.

Del Negro, CA Chandler, SH Physiological and theoretical analysis of K+ currents controlling discharge in neonatal rat mesencephalic trigeminal neurons Journal of neurophysiology. , 1997; 77(2): 537-53.

20Jan

A vertebrate photoreceptor uses a G-protein receptor (rhodopsin) and a G-protein cascade to produce the electrical response that signals a change in light intensity. Powerful new techniques have made it possible to understand the working of this cascade in extraordinary detail. The reason for this is that practically every protein involved in the cascade in a photoreceptor, from the pigment molecule rhodopsin to the G-protein and channels, but including also a large number of control proteins, are expressed only in the photoreceptors and nowhere else in the body. This makes it possible with genetic techniques to create mice in which these proteins have been knocked out, over or under expressed, or replaced with proteins of modified structure. We use electrical recording to study the effects of such genetic alterations on the light responses of mouse rods and cones, in order to understand the role of these proteins in the visual cascade. We are especially interested in modulatory enzymes and their function in light and dark adaptation. We also have a long-standing interest in mechanisms of photoreceptor degeneration in genetically inherited disease.

Publications

A selected list of publications:

Fain Gordon, Sampath Alapakkam P Rod and cone interactions in the retina F1000Research, 2018; 7: .

Morshedian Ala, Woodruff Michael L, Fain Gordon L Role of recoverin in rod photoreceptor light adaptation The Journal of physiology, 2018; 596(8): 1513-1526.

Morshedian Ala, Toomey Matthew B, Pollock Gabriel E, Frederiksen Rikard, Enright Jennifer M, McCormick Stephen D, Cornwall M Carter, Fain Gordon L, Corbo Joseph C Cambrian origin of the CYP27C1-mediated vitamin A Royal Society open science, 2017; 4(7): 170362.

Morshedian Ala, Fain Gordon L Light adaptation and the evolution of vertebrate photoreceptors The Journal of physiology, 2017; 595(14): 4947-4960.

Kaylor Joanna J, Xu Tongzhou, Ingram Norianne T, Tsan Avian, Hakobyan Hayk, Fain Gordon L, Travis Gabriel H Blue light regenerates functional visual pigments in mammals through a retinyl-phospholipid intermediate Nature communications, 2017; 8(1): 16.

Morshedian Ala, Fain Gordon L The evolution of rod photoreceptors Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 2017; 372(1717): 16.

Ingram Norianne T, Sampath Alapakkam P, Fain Gordon L Why are rods more sensitive than cones? The Journal of physiology, 2016; 594(19): 5415-26.

Reingruber Jürgen, Holcman David, Fain Gordon L How rods respond to single photons: Key adaptations of a G-protein cascade that enable vision at the physical limit of perception BioEssays : news and reviews in molecular, cellular and developmental biology, 2015; 37(11): 1243-52.

Morshedian Ala, Fain Gordon L Single-photon sensitivity of lamprey rods with cone-like outer segments Current biology : CB, 2015; 25(4): 484-7.

Reingruber Jürgen, Pahlberg Johan, Woodruff Michael L, Sampath Alapakkam P, Fain Gordon L, Holcman David Detection of single photons by toad and mouse rods Proceedings of the National Academy of Sciences of the United States of America, 2013; 110(48): 19378-83.

Chen Ching-Kang, Woodruff Michael L, Chen Frank S, Chen Yenlin, Cilluffo Marianne C, Tranchina Daniel, Fain Gordon L Modulation of mouse rod response decay by rhodopsin kinase and recoverin The Journal of neuroscience : the official journal of the Society for Neuroscience, 2012; 32(45): 15998-6006.

Chen Jeannie, Woodruff Michael L, Wang Tian, Concepcion Francis A, Tranchina Daniel, Fain Gordon L Channel modulation and the mechanism of light adaptation in mouse rods The Journal of neuroscience : the official journal of the Society for Neuroscience, 2010; 30(48): 16232-40.

Fain Gordon L, Hardie Roger, Laughlin Simon B Phototransduction and the evolution of photoreceptors Current biology : CB, 2010; 20(3): R114-24.

Okawa Haruhisa, Sampath Alapakkam P, Laughlin Simon B, Fain Gordon L ATP consumption by mammalian rod photoreceptors in darkness and in light Current biology : CB, 2008; 18(24): 1917-21.

Dizhoor Alexander M, Woodruff Michael L, Olshevskaya Elena V, Cilluffo Marianne C, Cornwall M Carter, Sieving Paul A, Fain Gordon L Night blindness and the mechanism of constitutive signaling of mutant G90D rhodopsin The Journal of neuroscience : the official journal of the Society for Neuroscience, 2008; 28(45): 11662-72.

Fain GL Why photoreceptors die (and why they don’t), BioEssays, 2006; 28: 344-354.

20Jan

Christopher Colwell, Ph.D.

Faculty Member

Biography

Christopher S. Colwell is a Neuroscientist who has served on the UCLA School of Medicine faculty since he joined the Department of Psychiatry and Biobehavioral Sciences in 1997. He became a Professor in 2008. Dr. Colwell earned his B.S. in Neuroscience from Vanderbilt University in 1985. During this time, he started his research in circadian rhythms under the mentorship of Dr. T. Page. Dr. Colwell earned his Ph.D. in Biology at the University of Virginia in 1991. His thesis work explored the neural mechanisms by which light regulates circadian rhythms. Dr. Colwell continued this line of research during a postdoctoral fellowship at the University of Virginia with Dr. G. Block. A second postdoctoral fellowship was carried out on the topics of motor control and excitotoxicity in the laboratory of Dr. M. Levine at UCLA. Dr. Colwell learned how to utilize imaging techniques to measure calcium levels inside neurons while a visiting scientist in the laboratory of Dr. Konnerth at the University of Saarland, Germany. Since Dr. Colwell’s faculty appointment at UCLA, his laboratory’s research has focused on understanding the mechanisms underlying circadian rhythms in mammals. Dysfunction in the timing these daily cycles is a key symptom in a number of neurological and psychiatric disorders. Better understanding the basic biology of this timing system should result in new therapies to improve the quality of life of these patients and the people who care for them.