Oxytocin brain circuits in lactating rats
Final Report Abstract
In our project we gained by recombinant viruses selective genetic access to hypothalamic OXT neurons to study their connectivity and control their activity by optogenetic means. We found axons of hypothalamic OXT neurons in the majority of forebrain regions, including the central amygdala (CeA), a structure critically involved in OXT-mediated fear suppression. In vitro, exposure of channelrhodopsin-2 expressing OXT axons to blue-light activated a local GABAergic circuit that inhibited neurons in the output region of the CeA. Remarkably, in vivo, local blue-light induced endogenous OXT release robustly decreased freezing responses in fearconditioned rats. Our results thus show widespread central projections of hypothalamic OXT neurons and demonstrate for the first time that OT release from local axonal endings can specifically control region-associated behaviors.
Publications
- (2012): Evoked axonal oxytocin release in the central amygdala attenuates fear response. Neuron 73: 553-566
Knobloch, S., Charlet, A., Hoffmann, L.C., Eliava, M., Khrulev, S., Cetin, A.H., Osten, P., Schwarz, M. K., Seeburg, P.H., Stoop, R., and Grinevich, V.
(See online at https://doi.org/10.1016/j.neuron.2011.11.030) - (2012): The hypothalamoneurohypophyseal system: from genome to physiology. J. Neuroendocrinology 24: 539-553
Murphy, D., Konopacka, A., Hindmarch, C., Paton, J.F.R., Sweedler, J.V., Gillette, M., Ueta, Y., Grinevich, V., Lozic, M., and Japundzic-Zigon, N.
