New Publication: A revised conceptual framework for mouse vomeronasal pumping and stimulus sampling

February 19, 2024

Christoph Hamacher, Rudolf Degen, Melissa Franke, Victoria K. Switacz, David Fleck, Raghu Ram Katreddi, Andres Hernandez-Clavijo, Martin Strauch, Nao Horio, Enno Hachgenei, Jennifer Spehr, Stephen D. Liberles, Dorit Merhof, Paolo E. Forni, Geraldine Zimmer-Bensch, Yoram Ben-Shaul, and Marc Spehr (2024) A revised conceptual framework for mouse vomeronasal pumping and stimulus sampling, Current Biology 34,

Show abstract
The physiological performance of any sensory organ is determined by its anatomy and physical properties. Consequently, complex sensory structures with elaborate features have evolved to optimize stimulus detection. Understanding these structures and their physical nature forms the basis for mechanistic insights into sensory function. Despite its crucial role as a sensor for pheromones and other behaviorally instructive chemical cues, the vomeronasal organ (VNO) remains a poorly characterized mammalian sensory structure. Fundamental principles of its physico-mechanical function, including basic aspects of stimulus sampling, remain poorly explored. Here, we revisit the classical vasomotor pump hypothesis of vomeronasal stimulus uptake. Using advanced anatomical, histological, and physiological methods, we demonstrate that large parts of the lateral mouse VNO are composed of smooth muscle. Vomeronasal smooth muscle tissue comprises two subsets of fibers with distinct topography, structure, excitation-contraction coupling, and, ultimately, contractile properties. Specifically, contractions of a large population of noradrenaline-sensitive cells mediate both transverse and longitudinal lumen expansion, whereas cholinergic stimulation targets an adluminal group of smooth muscle fibers. The latter run parallel to the VNO’s rostro-caudal axis and are ideally situated to mediate antagonistic longitudinal constriction of the lumen. This newly discovered arrangement implies a novel mode of function. Single-cell transcriptomics and pharmacological profiling reveal the receptor subtypes involved. Finally, 2D/3D tomography provides non-invasive insight into the intact VNO’s anatomy and mechanics, enables measurement of luminal fluid volume, and allows an assessment of relative volume change upon noradrenergic stimulation. Together, we propose a revised conceptual framework for mouse vomeronasal pumping and, thus, stimulus sampling.

News from ECRO 2023 in Nijmegen

October 6, 2023

7 members of the Chemosensation laboratory attended the annual meeting of the European Chemoreception Research Organization (ECRO). They represented the lab in full forces: Victoria, Christoph, Johanna and Moritz successfully presented their projects on posters. Additionally, Victoria, Andres and Moritz organized a symposium called ‘Novel perspectives in mouse olfaction’, inviting junior group leaders to present their current work. The Spehr lab was represented with a talk in this symposium held by Friederike.
Johanna received a ECRO travel grant to cover for her expenses. Congrats Johanna!

News from the ETW2023

June 18, 2023

Five members of our group, Jerome Schröer, Lina Kenzler, David Fleck, Michelle Nowara, and Ilian Schröder (from left to right in the photo), attended the European Testis Workshop 2023 (ETW2023). This workshop brought together experts from the fields of reproductive biology and medicine to share their insights.

Four of our participants received funding from the Male Contraceptive Initiative (MCI) to cover their travel expenses. Lina Kenzler, Michelle Nowara, Jerome Schröer, and Ilian Schröder were the recipients of this grant, enabling their valuable contributions to the conference.

News from AChemS 2023

June 16, 2023

Lena Terlau, Friederike Seifert, Stefanie Kurth, Melissa Franke, and Marc Spehr attended the annual meeting of the Association for Chemoreception Sciences (AChemS) 2023, which took place in Bonita Springs, Florida. 

Lena received a travel grant from the European Chemoreception Research Organization (ECRO) that funded her participation. Moreover, at the meeting, Lena won the prestigious AChemS Award for Undergraduate Research for her poster presentation entitled “Insights into Adult Neurogenesis of Vomeronasal Sensory Neurons” Congratulations, Lena!!!

News from NWG Göttingen

March 25, 2023

Victoria Switacz, Hannah Tröger, Moritz Nesseler and Friederike Seifert travelled to Göttingen and participated at the 15th Göttingen meeting of the German Neuroscience Society. They all successfully presented great posters.
See you again in 2025, Göttingen!

Friederike returns from Pennsylvania

October 17, 2022

Friederike came back from a 6-month research stay at Ma lab, University of Pennsylvania, Philadelphia. She learned to do in vivo virus-injections into the accessory olfactory bulb. These injections were used to chemogenetically inhibit Mitral cells during behavioural experiments.

News from ECRO 2022

September 4, 2022

Marc Spehr, Andres Hernandez-Clavijo, Hannah-Lena Tröger, Moritz Nesseler, Lena Terlau and Victoria Switacz participated in the annual meeting of the European Chemoreception Research Organization (ECRO) 2022—which took place in August in Berlin, Germany. An excellent opportunity to network and meet fellow scientists! See you again in Nijmegen, the Netherlands, for ECRO 2023!

News from ASA 2022

July 1, 2022

On the annual meeting of the American Society for Andrology (ASA) 2022—which took place in May in La Jolla, California, USA—Lina Kenzler presented her data and was awarded an ASA travel award as well as a travel grant from the Male Contraceptive Initiative (MCI).

New Publication: Ventral striatal islands of Calleja neurons control grooming in mice

November 30, 2021

Zhang Y, Vargas Cifuentes L, Wright K, Bhattarai J, Mohrhardt J, Fleck D, Janke E, Jiang C, Cranfill S, Goldstein N, chreck M, Moberly A, Yu Y, Arenkiel B, Betley J, Luo W, Stegmaier J, Wesson D, Spehr M, Fuccillo M, Ma M (2021) Ventral striatal islands of Calleja neurons control grooming in mice. Nature Neuroscience 24 (12). DOI: 10.1038/s41593-021-00952-z

Show abstract
The striatum comprises multiple subdivisions and neural circuits that differentially control motor output. The islands of Calleja (IC) contain clusters of densely packed granule cells situated in the ventral striatum, predominantly in the olfactory tubercle (OT). Characterized by expression of the D3 dopamine receptor, the IC are evolutionally conserved, but have undefined functions. Here, we show that optogenetic activation of OT D3 neurons robustly initiates self-grooming in mice while suppressing other ongoing behaviors. Conversely, optogenetic inhibition of these neurons halts ongoing grooming, and genetic ablation reduces spontaneous grooming. Furthermore, OT D3 neurons show increased activity before and during grooming and influence local striatal output via synaptic connections with neighboring OT neurons (primarily spiny projection neurons), whose firing rates display grooming-related modulation. Our study uncovers a new role of the ventral striatum’s IC in regulating motor output and has important implications for the neural control of grooming.

News from SSR 2021

November 19, 2021

On the annual meeting of the Society for the Study of Reproduction (SSR) 2021 which will take place in December in Saint-Louis, Missouri, USA, Lina Kenzler and Justine Fischoeder will present their respective data in posters as well as in virtual flash talks.

Lina Kenzler was awarded an SSR trainee-travel award. Justine won an SSR trainee-travel award as well and also received travel grants from the Male Contraceptive Initiative (MCI) and the Molecular Science & Engineering Profile Area.