 The two images on the left (click for larger size) are of mouse olfactory bulbs imaged for different neuron types. The output neurons, also known as mitral cells, are expressing a genetically encoded yellow fluorescent protein (green/yellow). Immunolabeling for brain derived neurotrophic factor (BDNF; red) indicates localization of BDNF to interneurons (red) of the external plexiform layer, as well as to the mitral cell layer (red plus green = yellow). All nuclei are stained with DAPI (blue). The difference between the two olfactory bulbs is the amount of olfactory information, ie the sensory input to the olfactory bulb from the nose. The top image is from a bulb with unchanged input, while the bottom bulb received reduced sensory input as compared to the first. Note that in the lower image the size of the red 'stripe' is smaller indicating BDNF immunolabeling in lost in the external plexiform layer. In summary, these images indicate that in the olfactory bulb, neurogenesis and/ or neurite growth is regulated by both the amount of stimulus and the amount of BDNF. We are currently investigating what, if any, role the BDNF precursor proBDNF plays in this model. Peripheral olfaction: A recent project focued on two ion channels hypothesized to be crucially involved in rodent vomeronasal organ (VNO) sensory transduction. The first channel is the type 2 canonical transient receptor potential channel (TRPC2) and the second channel is the type 3 inositol trisphosphate receptor channel (IP3R3). Both channels conduct calcium, appear to be activated during the VNO receptor-potential, and form a protein-protein interaction. A chaperone-like protein termed receptor transporting protein 1 (RTP1) can increase the amount of functional TRPC2 in the cell surface membrane in vitro. This result was somewhat unexpected as RTP1 was previously thought to interact with G-protein coupled receptors and not ion channels. Please see our article in BMC Neuroscience for more information. Current Research Plans: How does the taste system encode sodium stimuli? Does coding change with physiological stress or learning? |
Dissertation Research |