Representation of gustatory and olfactory signals in GC. It had long been thought that primary sensory cortices (i.e., the first cortical areas that respond to sensory information) could only process information from a single sense (e.g., visual cortex could only respond to light). However recent experiments have shown that these areas respond to information from many modalities. We are using in vivo multielectrode recordings in behaving rats to characterize the neural activity of single neurons in gustatory cortex (the primary cortical area for taste) in response to tastes and odors.

Modulation of chemosensory responses by experience with flavor. After experiencing a flavor (a mixture of taste and odor), an odor becomes associated with that taste. This is experience is why many odors are describe using taste qualities (e.g., vanilla smells “sweet”). We are using in vivo multielectrode recordings in behaving rats to investigate how experience with a flavor modulates the response of neurons in gustatory cortex to tastes and odors. In particular, we are interested in understanding how the response to the combination of a taste and odor (flavor) is different than that of the response to the taste or odor alone. 

Modulation of chemosensory activity by mismatching odor-tastes mixtures. While the taste and odor components of a flavor act synergistically, when a taste is mismatched with an odor (e.g., pairing a “sweet” odor with a sour taste) the perception of both components are disrupted. In vivo multielectrode recordings in behaving rats are being used to determine how mismatching odors and tastes modulates neural activity in areas important for flavor. 

Publications

Stocke SK, Samuelsen CL (2021) A drivable optrode for use in chronic electrophysiology and optogenetic experiments. J Neurosci Methods. 15;348:108979. 

McQueen KA, Fredericksen KE, Samuelsen CL (2020) Experience informs consummatory choices for congruent and incongruent odor-taste mixtures in rats. Chem Senses 45(5):371-382.

Fredericksen KE, McQueen KA, Samuelsen CL (2019) Experience-dependent c-Fos expression in the mediodorsal thalamus varies with chemosensory modality. Chem Senses 44(1):41-49.

Bamji-Stocke S, Biggs BT, Samuelsen CL (2018) Experience-dependent c-Fos expression in the primary chemosensory cortices of the rat. Brain Res 1701:189-195.

Samuelsen CL, Fontanini A (2017) Processing of intraoral olfactory and gustatory signals in the gustatory cortex of awake rats. J. Neurosci 37(2):244-257.

Samuelsen CL, Gardner MP, Fontanini A (2013) Thalamic contribution to cortical processing of taste and expectation. J Neurosci33(5):1815-27.

Samuelsen CL, Gardner MP, Fontanini A (2012) Effects of cue-triggered expectation on cortical processing of taste. Neuron 74: 410-422.

Samuelsen CL, Meredith M (2011) Oxytocin antagonist disrupts male mouse medial amygdala response to chemical-communication signals. Neuroscience 180: 96-104.

Samuelsen CL, Meredith M (2009) The vomeronasal organ is required for the male mouse medial amygdala response to chemical-communication signals, as assessed by immediate early gene expression. Neuroscience 164: 1468-1476.

Mast TG, Samuelsen CL (2009) Human pheromone detection by the vomeronasal organ: unnecessary for mate selection? Chem Senses 34: 529-531.

Samuelsen CL, Meredith M (2009) Categorization of biologically relevant chemical signals in the medial amygdala. Brain Res 1263: 33-42.