Leptin-Responsive GABAergic Neurons Regulate Fertility through Pathways That Result in Reduced Kisspeptinergic Tone
Year: 2014
Type: article
Abstract: The adipocyte-derived hormone leptin plays a critical role in the central transmission of energy balance to modulate reproductive function. However, the neurocircuitry underlying this interaction remains elusive, in part due to incomplete knowledge of first-order leptin-responsive neurons. To address this gap, we explored the contribution of predominantly inhibitory (GABAergic) neurons versus excitatory (glutamatergic) neurons in the female mouse by selective ablation of the leptin receptor in each neuronal population: Vgat-Cre;Lepr(lox/lox) and Vglut2-Cre;Lepr(lox/lox) mice, respectively. Female Vgat-Cre;Lepr(lox/lox) but not Vglut2-Cre;Lepr(lox/lox) mice were obese. Vgat-Cre;Lepr(lox/lox) mice had delayed or absent vaginal opening, persistent diestrus, and atrophic reproductive tracts with absent corpora lutea. In contrast, Vglut2-Cre;Lepr(lox/lox) females exhibited reproductive maturation and function comparable to Lepr(lox/lox) control mice. Intracerebroventricular administration of kisspeptin-10 to Vgat-Cre;Lepr(lox/lox) female mice elicited robust gonadotropin responses, suggesting normal gonadotropin-releasing hormone neuronal and gonadotrope function. However, adult ovariectomized Vgat-Cre;Lepr(lox/lox) mice displayed significantly reduced levels of Kiss1 (but not Tac2) mRNA in the arcuate nucleus, and a reduced compensatory luteinizing hormone increase compared with control animals. Estradiol replacement after ovariectomy inhibited gonadotropin release to a similar extent in both groups. These animals also exhibited a compromised positive feedback response to sex steroids, as shown by significantly lower Kiss1 mRNA levels in the AVPV, compared with Lepr(lox/lox) mice. We conclude that leptin-responsive GABAergic neurons, but not glutamatergic neurons, act as metabolic sensors to regulate fertility, at least in part through modulatory effects on kisspeptin neurons.
Source: Journal of Neuroscience
Language: English
Subfield: Reproductive Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Awards: Boston Area Diabetes Endocrinology Research Center, The AgRP / POMC -> Paraventricular (PVH) -> Parabrachial (PBN) -> Limbic/Reward Satiety Circuit, The Kiss1 system in the neuroendocrine control of reproduction, Reproductive Physiology of Gonadotropin Synthesis, Leptin, GABAergic Neurons and the Feedback / Feedforward Regulation of Energy Balance, Boston Nutrition Obesity Research Center, The Kiss1 system in the neuroendocrine control of reproduction, Harvard Reproductive Endocrine Sciences Center, The Epigenetic Regulation of Puberty, Intellectual and Developmental Disablities Research Center, Harvard Reproductive Endocrine Sciences Center, Training Grant in Academic Endocrinology, Reproductive physiology of gonadotropin synthesis
OpenAlex ID: W1998266086