Olfactory Inputs to Hypothalamic Neurons Controlling Reproduction and Fertility

Howard Hughes Medical Institute, Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Cell (Impact Factor: 33.12). 12/2005; 123(4):669-82. DOI: 10.1016/j.cell.2005.08.039
Source: PubMed

ABSTRACT In order to gain insight into sensory processing modulating reproductive behavioral and endocrine changes, we have aimed at identifying afferent pathways to neurons synthesizing luteinizing hormone-releasing hormone (LHRH, also known as gonadotropin-releasing hormone [GnRH]), a key neurohormone of reproduction. Injection of conditional pseudorabies virus into the brain of an LHRH::CRE mouse line led to the identification of neuronal networks connected to LHRH neurons. Remarkably, and in contrast to established notions on the nature of LHRH neuronal inputs, our data identify major olfactory projection pathways originating from a discrete population of olfactory sensory neurons but fail to document any synaptic connectivity with the vomeronasal system. Accordingly, chemosensory modulation of LHRH neuronal activity and mating behavior are dramatically impaired in absence of olfactory function, while they appear unaffected in mouse mutants lacking vomeronasal signaling. Further visualization of afferents to LHRH neurons across the brain offers a unique opportunity to uncover complex polysynaptic circuits modulating reproduction and fertility.

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Available from: Lynn Enquist, Aug 03, 2015
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    • "Removal of the vomeronasal organs or lesioning of the accessory olfactory bulbs results in the disappearance of the effect of the partner ( Beltramino and Taleisnik , 1983 ) . However , this strict relationship between the accessory olfactory system and partner cues in rodents has been challenged by Yoon et al . ( 2005 ) who used transgenic mice to demonstrate the presence of direct pro - jections from the main olfactory bulbs to GnRH neurons but none from the accessory olfactory system . While much less research has been carried out in non - rodent mammals effects of olfactory cues from sexual partners appear to primarily involve air - born odors . T"
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