Publications by authors named "K V GAVRIKOV"
The purpose of this study was to evaluate the expression patterns of nicotinic and muscarinic ACh receptors (nAChRs and mAChRs, respectively) in relation to one another and to understand their effects on rabbit retinal ganglion cell response properties. Double-label immunohistochemistry revealed labeled inner-retinal cell bodies and complex patterns of nAChR and mAChR expression in the inner plexiform layer. Specifically, the expression patterns of m1, m4, and m5 muscarinic receptors overlapped with those of non-α7 and α7 nicotinic receptors in presumptive amacrine and ganglion cells.
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- * Recent research shows that the intracellular chloride concentration ([Cl(−)](i)) varies within SACs, being high in proximal regions and low in distal ones, which influences how SACs respond to GABA neurotransmitters, affecting their directional light responses.
- * A computational model suggests that for SACs to produce strong direction-selective responses, the chloride gradient must create different effects at proximal (depolarization) and distal (hyperpolarization) sites, and
Displaced starburst amacrine cells (SACs) are retinal interneurons that exhibit GABA( A ) receptor-mediated and Cl (-) cotransporter-mediated, directionally selective (DS) light responses in the rabbit retina. They depolarize to stimuli that move centrifugally through the receptive field surround and hyperpolarize to stimuli that move centripetally through the surround (Gavrikov et al, PNAS 100(26):16047-16052, 2003, PNAS 103(49):18793-18798, 2006). They also play a key role in the activity of DS ganglion cells (DS GC; Amthor et al, Vis Neurosci 19:495-509 2002; Euler et al, Nature 418:845-852, 2002; Fried et al, Nature 420:411- 414, 2002; Gavrikov et al, PNAS 100(26):16047-16052, 2003, PNAS 103(49):18793-18798, 2006; Lee and Zhou, Neuron 51:787-799 2006; Yoshida et al, Neuron 30:771-780, 2001).
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- The study investigates how light responses that are selective for the direction of image motion occur in the starburst amacrine cells in the retina, focusing on the role of chloride cotransporters NKCC and KCC.
- It finds that blocking NKCC2 and KCC2 influences the excitability of starburst cells and disrupts their ability to respond directionally to light.
- The research highlights that the different localizations of NKCC2 and KCC2 on proximal and distal dendrites allow for distinct GABA responses, which are crucial for encoding complex visual information in the nervous system.
Cation--chloride cotransporters mediate neural computation in the retina.
Proc Natl Acad Sci U S A
December 2003
The ability of directionally selective (DS) retinal ganglion cells to respond selectively to stimulus motion in one direction is a classic unresolved example of computation in a local neural circuit. Recent evidence indicates that DS responses occur first in the retina in the dendrites of starburst amacrine cells (interneurons presynaptic to the ganglion cells). We report that the directional responses of starburst-cell dendrites and DS ganglion cells are highly sensitive to the polarity of the transmembrane chloride gradient.
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