| Title: | An ex vivo preparation of the intact mouse vomeronasal organ and accessory olfactory bulb |
| Address: | "Department of Anatomy and Neurobiology, Washington University School of Medicine, Campus Box 8108, 660 S. Euclid Ave, Saint Louis, MO 63110, United States. meeks@pcg.wustl.edu " |
| DOI: | 10.1016/j.jneumeth.2008.11.013 |
| ISSN/ISBN: | 0165-0270 (Print) 1872-678X (Electronic) 0165-0270 (Linking) |
| Abstract: | "The accessory olfactory system (AOS) in mammals detects and processes information from liquid-phase environmental odorants, including pheromones. The AOS carries out tasks such as individual recognition, learning, and decision-making with relatively few stages of neural processing; it thus represents an attractive system for investigating the neural circuits that carry out these functions. Progress in understanding the AOS has long been impeded by its relative inaccessibility to standard physiological approaches. In this report, we detail a novel dissection and tissue perfusion strategy that improves access to the accessory olfactory bulb (AOB) while maintaining afferent connections from sensory neurons in the vomeronasal organ (VNO). Mitral cells demonstrated spontaneous and evoked firing patterns consistent with recent in vivo reports. We assayed cell degradation in the AOB tissue using Fluoro-Jade C and found that the VNO and AOB glomerular, external plexiform, and mitral cell layers showed minimal signs of degeneration for up to 6h. Whereas histology indicated some degeneration in the deep inhibitory granule cell layer over time, electrophysiological assays demonstrated intact inhibitory function on mitral cells. Pharmacological blockade of GABA(A) receptors with 3microM SR95531 (gabazine) resulted in increased evoked mitral cell activity. Furthermore, mitral cells displayed suppression of responses to preferred urine stimuli when preferred and non-preferred stimuli were mixed, an effect thought to involve functional laterally connected inhibition. These results demonstrate the utility of whole mount ex vivo preparations for studying sensory processing in the AOS, and suggest that similar strategies may improve experimental access to other difficult-to-study neural circuits" |
| Keywords: | "Action Potentials/drug effects/physiology Animals Diffusion Chambers, Culture/instrumentation/methods Dissection/*methods Electrophysiology/instrumentation/*methods Fluoresceins Male Mice Mice, Inbred C57BL Mice, Inbred DBA Nerve Degeneration/pathology/ph;" |
| Notes: | "MedlineMeeks, Julian P Holy, Timothy E eng R01 DC005964/DC/NIDCD NIH HHS/ R01 DC005964-05/DC/NIDCD NIH HHS/ R01-DC005964/DC/NIDCD NIH HHS/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Netherlands 2008/12/17 J Neurosci Methods. 2009 Mar 15; 177(2):440-7. doi: 10.1016/j.jneumeth.2008.11.013. Epub 2008 Nov 27" |
