Characterization of cell types and connectivity of the deep cerebellar nuclei

• Main Author: Lim, Zoe Hui
• Other Authors: Chen I-Ming, Albert
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Science
• Online Access: http://hdl.handle.net/10356/67153
• Institution: Nanyang Technological University

Previous tracing experiments have revealed the existence of bidirectional projections between the cerebellum and hypothalamus, and the cerebellum and hippocampus. These studies imply a role of the cerebellum in hypothalamic and hippocampal functions. To establish these projections in the mouse brain, lumafluor and 10kDa Biotinylated dextran amine (BDA) were injected into the hypothalamus and lateral nucleus of the cerebellum, respectively. Our tracing studies led to two conclusions. First, the retrograde tracing results coincide with previous studies that show direct deep cerebellar nuclei (DCN) projections to the hypothalamus in higher organisms. Second, the BDA tracing revealed potential direct connections between the DCN and hippocampus. To characterize DCN projection neurons, immunohistochemistry (IHC) was performed using vGluT2, TBR1 and Tfap2a antibodies. TBR1 is used as a marker for glutamatergic projection neurons and Tfap2a is used to characterize putative GABAergic neurons in the cerebellum. We found that TBR1 stains a subset of vGluT2 neurons which could potentially function as projection neurons. Tfap2a and TBR1 also highlighted mixed neuronal populations in the DCN that can be used for future characterization of neurons in the cerebellar nuclei. Taken together, our results indicate that direct projections from the cerebellum to hippocampus and hypothalamus exist in mice and we have begun to characterize the cells from which these connections may arise.