The aims of our project are:
1. Exploit the discovery of the PV1-nucleus (a rodent LTN homologue) to study its connectivity by means of antero- and retrograde tract-tracing experiments with viral vectors (AAV, pseudorabies).
2. Identify novel markers enriched in the PV1 of rodents and the LTN of primates (gene array techniques).
3. Evaluate the activity in the human LTN after adequate peripheral stimulation (tickling).
Knowledge of the wiring of the rodent PV1-nucleus and of its gene constituents in various species, coupled with MRI-experiments could provide clues to its physiological role.
Methods
Experiments are performed with a wide panel of different techniques: morphology (e.g. in situ hybridization), tract tracing with viral constructs, biochemistry, molecular-biology (e.g. gene-microarrays), magnetic resonance imaging (in humans), and behavioral studies.
Group members
Laurence Clement* (technician), Christiane Marti* (technician), Alexandre Babalian* (PhD), Franck Girard* (PhD), Viktoria Szabolcsi (MD), Elise Wattendorf* (PhD), Alessandro Bilella (PhD student), Diana Waldmeyer (PhD student). (*part time)
Funding
Intramural budget (University of Fribourg), private Foundations (Novartis foundation), Swiss National Science Foundation
Publications
• Mészár Z, Girard F, Saper CB, Celio MR. (2012) The lateral hypothalamic parvalbumin-immunoreactive (PV1) nucleus in rodents. J Comp Neurol. 2012;520(4):798-815.
• Girard F, Meszar Z, Marti C, Davis FP, Celio MR. (2011) Gene expression analysis in the parvalbumin-immunoreactive PV1 nucleus of the mouse lateral hypothalamus. Eur J Neurosci.;34: 1934-43
• Gerig AT, Celio MR. (2007) The human lateral tuberal nucleus: Immunohistochemical characterization and analogy to the rodent PV1-nucleus. Brain Res. 2007;1139:110-6.
well as its cyto- and myeloarchitecture, we concluded that this PV1-nucleus may correspond to the lateral tuberal nucleus (LTN) in humans (Gerig and Celio, 2007). This voluminous hypothalamic nucleus was first described in the human brain by Albert Kölliker in 1897, but its functions have yet to be elucidated.
3-D reconstruction of the localisation of the PV1-nucleus (red) in 50 adjacent coronal sections of the rat hypothalamus. Note the filiform, spaghetti-like structure of the nucleus and its intimate association with the optic tract (green). Gray: third ventricle.