Nipecotic acid: preferential accumulation in the cochlea by GABA uptake systems and selective retrograde transport to brainstem.
[3H]Nipecotic acid was shown to be preferentially accumulated by the same cochlear structures which selectively accumulate [3H]gamma-aminobutyric acid ([3H]-GABA), including the terminals of a subset of olivocochlear neurons. With both amino acids, olivocochlear fibers selectively transported label in a retrograde direction, from cochlea to brainstem. However, only [3H]nipecotic acid produced dense labeling, and labeling of cell bodies in the superior olive, presumably because it is metabolized very slowly. Nipecotic acid appears to provide a selective retrograde tracer, specific to neurons whose terminals exhibit preferential GABA uptake.
D000818:Animals; D001345:Autoradiography; D001693:Biological Transport, Active; D001933:Brain Stem / Q000166:cytology / Q000378:metabolism*; D003051:Cochlea / Q000294:innervation*; D004525:Efferent Pathways; D005849:Gerbillinae; D009476:Neurons, Efferent / Q000378:metabolism*; D009557:Nipecotic Acids / Q000378:metabolism*; D009847:Olivary Nucleus / Q000166:cytology / Q000378:metabolism; D011392:Proline / Q000031:analogs & derivatives*; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives / Q000378:metabolism*
D009557:Nipecotic Acids; C030278:nipecotic acid; D005680:gamma-Aminobutyric Acid; D011392:Proline; C010983:homoproline