Search
Presentation Details
| Poster #328 FOSTRAPPING Neural Networks Driven by Odor Stimulation |
| Saptarsi Mitra2 & Debra Ann Fadool1,2,3 1Department of Biological Science, Florida State University, Tallahassee, FL, United States 2Program In Neuroscience, Florida State University, Tallahassee, FL, United States 3Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States |
Mitral/tufted cells not only serve to output olfactory information, but are now known to project to downstream sites regulating energy balance at specific hypothalamic nuclei. Herein, we employed Fos-TRAP (targeted recombination in active populations) to functionally map neuronal populations in the brain that are active following odor stimulation. Male and female Fos2A-iCreER (TRAP2) mice were stimulated with isopropyl tiglate in a custom olfactometer using a cyclic pattern of odor stimulation. Using the olfactory bulb as a positive control, we observed an abundance of FOSTRAP neurons in the granule cell layer (***p<0.001), and moderate activation in the mitral cell layer (**p<0.01) in odor-stimulated mice. Significant activation was seen in both anterior and posterior piriform cortex subdivisions (**p<0.01). Discrete activation pattern was observed in the hypothalamic arcuate nucleus, paraventricular hypothalamic nucleus, dorsomedial hypothalamic nucleus, supramammillary nucleus and lateral hypothalamus (**p<0.01). Specific dendritic spine labeling in hippocampal granule and pyramidal neurons suggests a novel method to study plasticity in active neurons. Using Tbx21-cre mice with restricted EGFP expression in mitral and tufted cells, we screened downstream neural connectivity and observed axonal varicosities near c-Fos immunoreactive cells in the accessory olfactory bulb and cortical amygdala. Probing for calretinin in the olfactory bulb and oxytocin/vasopressin in the paraventricular nucleus revealed minimal co-expression with FOSTRAP/c-Fos, suggesting alternate activated populations in these areas. This study demonstrates that the FOSTRAP approach is a convenient tool for mapping odor-activated pathways in the brain. |