Similar articles

Abstract: Responses of 302 mitral/tufted (M/T) cells in the olfactory bulb were recorded from 42 anesthetized freely breathing rats using a 16-channel microwire electrode array. Saturated vapors of four pure chemicals, anisole, carvone, citral and isoamyl acetate were applied. After aligning spike trains to the initial phase of the inhalation after odor onset, the responses of M/T cells showed transient temporal features including excitatory and inhibitory patterns. Both odor-evoked patterns indicated that mammals recognize odors within a short respiration cycle after odor stimulus. Due to the small amount of information received from a single cell, we pooled results from all responsive M/T cells to study the ensemble activity. The firing rates of the cell ensembles were computed over 100 ms bins and population vectors were constructed. The high dimension vectors were condensed into three dimensions for visualization using principal component analysis. The trajectories of both excitatory and inhibitory cell ensembles displayed strong dynamics during odor stimulation. The distances among cluster centers were enlarged compared to those of the resting state. Thus, we presumed that pictures of odor information sent to higher brain regions were depicted and odor discrimination was completed within the first breathing cycle.

[1]Bathellier, B., van de Ville, D., Blu, T., Unser, M., Carleton, A., 2007. Wavelet-based multi-resolution statistics for optical imaging signals: application to automated detection of odour activated glomeruli in the mouse olfactory bulb. Neuroimage, 34(3):1020-1035.

[2]Bathellier, B., Buhl, D.L., Accolla, R., Carleton, A., 2008. Dynamic ensemble odor coding in the mammalian olfactory bulb: sensory information at different timescales. Neuron, 57(4):586-598.

[3]Buonviso, N., Chaput, M.A., Berthommier, F., 1996. Similarity of granular-induced inhibitory periods in pairs of neighboring mitral/tufted cells. J. Neurophysiol., 76(4):2393-2401.

[4]Buonviso, N., Amat, C., Litaudon, P., Roux, S., Royet, J.P., Farget, V., Sicard, G., 2003. Rhythm sequence through the olfactory bulb layers during the time window of a respiratory cycle. Eur. J. Neurosci., 17(9):1811-1819.

[5]Chaput, M.A., 1986. Respiratory-phase-related coding of olfactory information in the olfactory bulb of awake freely-breathing rabbits. Physiol. Behav., 36(2):319-324.

[6]Chaput, M.A., Buonviso, N., Berthommier, F., 1992. Temporal patterns in spontaneous and odour-evoked mitral cell discharges recorded in anaesthetized freely breathing animals. Eur. J. Neurosci., 4(9):813-822.

[7]Chen, T.W., Lin, B.J., Schild, D., 2009. Odor coding by modules of coherent mitral/tufted cells in the vertebrate olfactory bulb. PNAS, 106(7):2401-2406.

[8]Couto, A., Alenius, M., Dickson, B.J., 2005. Molecular, anatomical, and functional organization of the drosophila olfactory system. Curr. Biol., 15(17):1535-1547.

[9]Cury, K.M., Uchida, N., 2010. Robust odor coding via inhalation-coupled transient activity in the mammalian olfactory bulb. Neuron, 68(3):570-585.

[10]Davison, I.G., Katz, L.C., 2007. Sparse and selective odor coding by mitral/tufted neurons in the main olfactory bulb. J. Neurosci., 27(8):2091-2101.

[11]Egana, J.I., Aylwin, M.L., Maldonado, P.E., 2005. Odor response properties of neighboring mitral/tufted cells in the rat olfactory bulb. Neuroscence, 134(3):1069-1080.

[12]Feinstein, P., Mombaerts, P., 2004. A contextual model for axonal sorting into glomeruli in the mouse olfactory system. Cell, 117(6):817-831.

[13]Friedrich, R.W., Laurent, G., 2001. Dynamic optimization of odor representations by slow temporal patterning of mitral cell activity. Science, 291(5505):889-894.

[14]Isaacson, J.S., Cang, J.H., 2003. In vivo whole-cell recording of odor-evoked synaptic transmission in the rat olfactory bulb. J. Neurosci., 23(10):4108-4116.

[15]Kay, L.M., Laurent, G., 1999. Odor- and context-dependent modulation of mitral cell activity in behaving rats. Nat. Neurosci., 2(11):1003-1009.

[16]Laing, D.G., 1986. Identification of single dissimilar odors is achieved by humans with a single sniff. Physiol. Behav., 37(1):163-170.

[17]Leon, M., Johnson, B.A., 2003. Olfactory coding in the mammalian olfactory bulb. Brain Res. Rev., 42(1):23-32.

[18]Luo, M.M., Katz, L.C., 2001. Response correlation maps of neurons in the mammalian olfactory bulb. Neuron, 32(6):1165-1179.

[19]Meister, M., Bonhoeffer, T., 2001. Tuning and topography in an odor map on the rat olfactory bulb. J. Neurosci., 21(4):1351-1360.

[20]Mombaerts, P., 1996. Targeting olfaction. Curr. Opin. Neurobiol., 6(4):481-486.

[21]Restrepo, D., Doucette, W., Whitesell, J.D., Mctavish, T.S., Salcedo, E., 2009. From the top down: Flexible reading of a fragmented odor map. Trends Neurosci., 32(10):525-531.

[22]Rinberg, D., Koulakov, A., Gelperin, A., 2006. Sparse odor coding in awake behaving mice. J. Neurosci., 26(34):8857-8865.

[23]Rubin, B.D., Katz, L.C., 1999. Optical imaging of odorant representations in the mammalian olfactory bulb. Neuron, 23(3):499-511.

[24]Stopfer, M., 2005. Olfactory coding: inhibition reshapes odor responses. Curr. Biol., 15(24):R996-R998.

[25]Uchida, N., Mainen, Z.F., 2003. Speed and accuracy of olfactory discrimination in the rat. Nat. Neurosci., 6(11):1224-1229.

[26]Wellis, D.P., Scott, J.W., Harrison, T.A., 1989. Discrimination among odorants by single neurons of the rat olfactory bulb. J. Neurophysiol., 61(6):1161-1177.

[27]Wilson, R.I., Mainen, Z.F., 2006. Early events in olfactory processing. Annu. Rev. Neurosci., 29:163-201.