Highly Specific Olfactory Receptor Neurons for Types of Amino Acids in the Channel Catfish

• Published in: Journal of neurophysiology 2007-10, Vol.98 (4), p.1909-1918
• Main Authors: Nikonov, Alexander A, Caprio, John
• Format: Article
• Language: English
• Subjects: Amino Acids - pharmacology; Anesthesia; Animals; Data Interpretation, Statistical; Electrophysiology; Freshwater; Ictaluridae - physiology; Ictalurus punctatus; Odorants; Olfactory Bulb - physiology; Olfactory Receptor Neurons - physiology; Prosencephalon - physiology
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.00548.2007

Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana Submitted 15 May 2007; accepted in final form 2 August 2007 Odorant specificity to L - -amino acids was determined electrophysiologically for 93 single catfish olfactory receptor neurons (ORNs) selected for their narrow excitatory molecular response range (EMRR) to only one type of amino acid (i.e., Group I units). These units were excited by either a basic amino acid, a neutral amino acid with a long side chain, or a neutral amino acid with a short side chain when tested at 10 –7 to 10 –5 M. Stimulus-induced inhibition, likely for contrast enhancement, was primarily observed in response to the types of amino acid stimuli different from that which activated a specific ORN. The high specificity of single Group I ORNs to type of amino acid was also previously observed for single Group I neurons in both the olfactory bulb and forebrain of the same species. These results indicate that for Group I neurons olfactory information concerning specific types of amino acids is processed from receptor neurons through mitral cells of the olfactory bulb to higher forebrain neurons without significant alteration in unit odorant specificity. Address for reprint requests and other correspondence: J. Caprio, Department of Biological Sciences, 202 Life Sciences Bldg., Louisiana State University, Baton Rouge, LA 70803 (E-mail: jcap{at}lsu.edu )