@article {6877, title = {Comparing thoracic and intra-nasal pressure transients to monitor active odor sampling during odor-guided decision making in the mouse.}, journal = {Journal of Neuroscience Methods}, volume = {221}, year = {2014}, month = {2014 Jan 15}, pages = {8-14}, abstract = {

BACKGROUND: Recording of physiological parameters in behaving mice has seen an immense increase over recent years driven by, for example, increased miniaturization of recording devices. One parameter particularly important for odorant-driven behaviors is the breathing frequency, since the latter dictates the rate of odorant delivery to the nasal cavity and the olfactory receptor neurons located therein. NEW METHOD: Typically, breathing patterns are monitored by either measuring the breathing-induced temperature or pressure changes in the nasal cavity. Both require the implantation of a nasal cannula and tethering of the mouse to either a cable or tubing. To avoid these limitations we used an implanted pressure sensor which reads the thoracic pressure and transmits the data telemetrically, thus making it suitable for experiments which require a freely moving animal. RESULTS: Mice performed a Go/NoGo odorant-driven behavioral task with the implanted pressure sensor, which proved to work reliably to allow recording of breathing signals over several weeks from a given animal. COMPARISON TO EXISTING METHOD(S): We simultaneously recorded the thoracic and nasal pressure changes and found that measuring the thoracic pressure change yielded similar results compared to measurements of nasal pressure changes. CONCLUSION: Telemetrically recorded breathing signals are a feasible method to monitor odorant-guided behavioral changes in breathing rates. Its advantages are most significant when recording from a freely moving animal over several weeks. The advantages and disadvantages of different methods to record breathing patterns are discussed.

}, issn = {1872-678X}, doi = {10.1016/j.jneumeth.2013.09.006}, author = {Reisert, Johannes and Golden, Glen J and Matsumura, Koichi and Smear, Matt and Rinberg, Dmitry and Gelperin, Alan} } @article {2364, title = {Olfactory coding with all-or-nothing glomeruli.}, journal = {Journal of Neurophysiology}, volume = {98}, year = {2007}, month = {2007 Dec}, pages = {3134-42}, abstract = {

We present a model for olfactory coding based on spatial representation of glomerular responses. In this model distinct odorants activate specific subsets of glomeruli, dependent on the odorant{\textquoteright}s chemical identity and concentration. The glomerular response specificities are understood statistically, based on experimentally measured distributions of activation thresholds. A simple version of the model, in which glomerular responses are binary (the all-or-nothing model), allows us to account quantitatively for the following results of human/rodent olfactory psychophysics: 1) just noticeable differences in the perceived concentration of a single odor (Weber ratios) are as low as dC/C approximately 0.04; 2) the number of simultaneously perceived odors can be as high as 12; and 3) extensive lesions of the olfactory bulb do not lead to significant changes in detection or discrimination thresholds. We conclude that a combinatorial code based on a binary glomerular response is sufficient to account for several important features of the discrimination capacity of the mammalian olfactory system.

}, keywords = {Algorithms, Animals, Discrimination (Psychology), Mice, Models, Neurological, Odors, Olfactory Bulb, Olfactory Pathways, Olfactory Receptor Neurons, Psychomotor Performance, Psychophysics, Rats, Smell}, issn = {0022-3077}, doi = {10.1523/JNEUROSCI.3613-08.2008}, author = {Koulakov, Alexei and Gelperin, Alan and Rinberg, Dmitry} } @article {2368, title = {Olfactory neuronal dynamics in behaving animals.}, journal = {Seminars in Cell \& Developmental Biology}, volume = {17}, year = {2006}, month = {2006 Aug}, pages = {454-61}, abstract = {

More than 50 years have passed since the first recording of neuronal responses to an odor stimulus from the primary olfactory brain area, the main olfactory bulb. During this time very little progress has been achieved in understanding neuronal dynamics in the olfactory bulb in awake behaving animals, which is very different from that in anesthetized preparations. In this paper we formulate a new framework containing the main reasons for studying olfactory neuronal dynamics in awake animals and review advances in the field within this new framework.

}, keywords = {Anesthesia, Animal, Animals, Behavior, Brain, Conditioning (Psychology), Neuronal Plasticity, Olfactory Bulb, Olfactory Receptor Neurons, Rabbits, Rats, Synaptic Transmission}, issn = {1084-9521}, doi = {10.1523/JNEUROSCI.3613-08.2008}, author = {Rinberg, Dmitry and Gelperin, Alan} } @article {2365, title = {Sparse odor coding in awake behaving mice.}, journal = {The Journal of Neuroscience: The Official Journal of the Society for Neuroscience}, volume = {26}, year = {2006}, month = {2006 Aug 23}, pages = {8857-65}, abstract = {

Responses of mitral cells represent the results of the first stage of odor processing in the olfactory bulb. Most of our knowledge about mitral cell activity has been obtained from recordings in anesthetized animals. We compared odor-elicited changes in firing rate of mitral cells in awake behaving mice and in anesthetized mice. We show that odor-elicited changes in mitral cell firing rate were larger and more frequently observed in the anesthetized than in the awake condition. Only 27\% of mitral cells that showed a response to odors in the anesthetized state were also odor responsive in the awake state. The amplitude of their response in the awake state was smaller, and some of the responses changed sign compared with their responses in the anesthetized state. The odor representation in the olfactory bulb is therefore sparser in awake behaving mice than in anesthetized preparations. A qualitative explanation of the mechanism responsible for this phenomenon is proposed.

}, keywords = {Afferent, Anesthesia, Animals, Electrophysiology, Inbred C57BL, Male, Mice, Neurons, Odors, Olfactory Bulb, Smell, Wakefulness}, issn = {1529-2401}, doi = {10.1523/JNEUROSCI.3613-08.2008}, author = {Rinberg, Dmitry and Koulakov, Alex and Gelperin, Alan} } @article {2366, title = {Speed-accuracy tradeoff in olfaction.}, journal = {Neuron}, volume = {51}, year = {2006}, month = {2006 Aug 3}, pages = {351-8}, abstract = {

The basic psychophysical principle of speed-accuracy tradeoff (SAT) has been used to understand key aspects of neuronal information processing in vision and audition, but the principle of SAT is still debated in olfaction. In this study we present the direct observation of SAT in olfaction. We developed a behavioral paradigm for mice in which both the duration of odorant sampling and the difficulty of the odor discrimination task were controlled by the experimenter. We observed that the accuracy of odor discrimination increases with the duration of imposed odorant sampling, and that the rate of this increase is slower for harder tasks. We also present a unifying picture of two previous, seemingly disparate experiments on timing of odorant sampling in odor discrimination tasks. The presence of SAT in olfaction provides strong evidence for temporal integration in olfaction and puts a constraint on models of olfactory processing.

}, keywords = {Animals, Chemical, Discrimination Learning, Inbred C57BL, Male, Mice, Psychomotor Performance, Reaction Time, Smell, Stimulation}, issn = {0896-6273}, doi = {10.1523/JNEUROSCI.3613-08.2008}, author = {Rinberg, Dmitry and Koulakov, Alexei and Gelperin, Alan} }